Quantification of 10,11-dihydro-10-hydroxy carbamazepine and 10,11-epoxycarbamazepine as the main by-products in the electrochemical degradation of carbamazepine

Carbamazepine (CBZ) is one of the most widely used antiepileptic drugs in Malaysia. It was detected frequently in wastewater. The electrochemical treatment process has been applied for the degradation of CBZ using graphite-PVC as an anode under these conditions: 0.5 g sodium chloride (NaCl)) as supporting electrolyte, 5 V and 0-60 min electrolysis time in 100 mL of solution. However, 10,11-dihydro10-hydroxy carbamazepine (HDX-CBZ) and 10,11-epoxycarbamazepine (EPX-CBZ) as the main by-product have been analysed and quantified using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS). Both by-products were analysed in positive ionization mode, and they were separated on a chromatographic C18 column (5 μm, 2 mm × 150 mm) at a flow rate of 0.3 mL/min. Solid-phase extraction (SPE) was applied as a pre-concentration step for the enhancement of the sensitivity and detectability for both HDX-CBZ and EPX-CBZ by-products. Methanol (MeOH) has been selected as the best elution solvent for both by-products compared to methyl tertiary butyl ether (MTBE) and acetone (AC). However, the recovery was 85% and 92% for HDX-CBZ and EPX-CBZ by-products, respectively. The limit of quantification (LOQ) was 0.588 and 0.109 µg/L for HDX-CBZ and EPX-CBZ by-products, respectively. After 20 min of electrolysis time, both by-products HDX-CBZ and EPX-CBZ appeared at maximum concentrations of 343 and 144 μg/L then they were decreased to 17.2 and 9.8 μg/L, respectively, after 40 min. At the end of electrochemical treatment, both by-products were completely eliminated after 60 min.

Comparison of oxcarbazepine efficacy and MHD concentrations relative to age and BMI: Associations among ABCB1, ABCC2, UGT2B7, and SCN2A polymorphisms

Genetic polymorphisms are related to the concentration and efficacy of oxcarbazepine (OXC). 10-Hydroxycarbazepine (MHD) is the major pharmacologically active metabolite of OXC, and it exerts an antiepileptic effect. This study aimed to explore the connection between the MHD concentration and genes such as ATP-binding cassette B1 (ABCB1), ATP-binding cassette C2 (ABCC2), UDP-glucuronosyltransferase-2B7 and sodium voltage-gated channel alpha subunit 2 (SCN2A), which participate in the antiepileptic function of OXC.Total 218 Chinese epileptic patients, were stratified into different groups according to their age, body mass index (BMI) and OXC efficacy. The genotypes of 7 single nucleotide polymorphisms in all subjects were determined by polymerase chain reaction-improved multiple ligase detection reaction assay. The MHD plasma concentration was detected by high-performance liquid chromatography and then standardized through dosage and body weight.In general, the ABCC2 rs2273697 mutant (P = .026) required a significantly higher standardized MHD concentration. For age groups, carriers of the ABCC2 rs2273697 mutant showed a significantly higher standardized MHD concentration than noncarriers in the juvenile group (P = .033). In terms of BMI, a significantly higher standardized MHD concentration was found in the ABCB1 rs2032582 mutant of the normal weight group (P = .026). The SCN2A rs17183814 mutant required a significantly higher OXC maintenance (P = .014) in the low-weight group, while lower OXC maintenance dose (P = .044) and higher standardized MHD concentration (P = .007) in the overweight group.The ABCC2 rs2273697 polymorphism was significantly associated with MHD plasma concentration in the whole patient cohort and in patients stratified by different ages, this finding provides potential theoretical guidance for the rational and safe clinical use of OXC.

Polymorphic Phase Transitions in Carbamazepine and 10,11-Dihydrocarbamazepine

Temperature-induced phase transitions in carbamazepine (CBZ) and 10,11-dihydrocarbamazepine (DHC) were studied by simultaneous differential scanning calorimetry-X-ray diffraction in this work. The transitions generally involve a transitional melt phase which is quickly followed by recrystallisation. The expansions of the unit cell as a function of temperature could be quantified and allow us to determine a directional order of stability in relation to the lattice constants. Dihydrocarbamazepine form II undergoes a conversion to form I by a localised melt phase. Carbamazepine (CBZ) form IV converts to form I at 182 °C, again by a localised intermediate melt phase. CBZ form II converted to form I at 119 °C by a pathway that appears to have included some melting, and form III underwent a part melt-recrystallisation and a part sublimation-recrystallisation to form I.

Oxcarbazepine oral suspension in young pediatric patients with partial seizures and/or generalized tonic-clonic seizures in routine clinical practice in China: a prospective observational study

BACKGROUND

This study aimed to assess efficacy and safety of oxcarbazepine (OXC) oral suspension in pediatric patients aged 2-5 years with partial seizures (PS) and/or generalized tonic-clonic seizures (GTCS) in real-world clinical practice in China.

METHODS

This 26-week, prospective, single-arm, multicenter, observational study recruited pediatric patients aged 2-5 years with PS or GTCS suitable for OXC oral suspension treatment based on physicians' judgments from 11 medical centers in China. Enrolled subjects started OXC oral suspension treatment as monotherapy or in combination with other antiepileptic drugs. Primary efficacy outcome was the percentage of pediatric subjects achieving ≥ 50% seizure frequency reduction at the end of the 26-week treatment. Secondary efficacy-related parameters and safety parameters such as adverse events (AEs) and serious AEs (SAEs) were also monitored during the 26-week treatment period.

RESULTS

Six hundred and six pediatric patients were enrolled and 531 (87.6%) completed the study. After 26 weeks of treatment, 93.3% subjects achieved ≥ 50% seizure frequency reduction, and 81.8% achieved 100% seizure frequency reduction compared to baseline. Among different seizure types, OXC was effective in all subjects with simple PS and in > 90% of subject with other type of seizure present in the study. AEs were observed in 49 (8.1%) subjects. Only three subjects experienced SAE. Rash (n = 18, 2.97%) was the most common AE. Only 17 subjects discontinued due to AEs.

CONCLUSION

This study, reporting the real-world data, further confirms the efficacy and good safety profile of OXC oral suspension in Chinese pediatric patients aged 2-5 years with PS and/or GTCS.

Risperidone for psychosis-induced aggression or agitation (rapid tranquillisation)

BACKGROUND

Aggressive, agitated or violent behaviour due to psychosis constitutes an emergency psychiatric treatment where fast-acting interventions are required. Risperidone is a widely accessible antipsychotic that can be used to manage psychosis-induced aggression or agitation.

OBJECTIVES

To examine whether oral risperidone alone is an effective treatment for psychosis-induced aggression or agitation.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (up to April 2017); this register is compiled by systematic searches of major resources (including AMED, BIOSIS CINAHL, Embase, MEDLINE, PsycINFO, PubMed, and registries of clinical trials) and their monthly updates, handsearches, grey literature, and conference proceedings. There are no language, date, document type, or publication status limitations for inclusion of records into the register.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing rapid use of risperidone and other drugs, combinations of drugs or placebo for people exhibiting aggression or agitation (or both) thought to be due to psychosis.

DATA COLLECTION AND ANALYSIS

We independently inspected all citations from searches, identified relevant abstracts, and independently extracted data from all included studies. For binary data we calculated risk ratio (RR) and for continuous data we calculated mean difference (MD), all with 95% confidence intervals (CI) and used a fixed-effect model. We assessed risk of bias for the included studies and used the GRADE approach to produce a 'Summary of findings' tables.

MAIN RESULTS

The review now contains data from nine trials (total n = 582) reporting on five comparisons. Due to risk of bias, small size of trials, indirectness of outcome measures and a paucity of investigated and reported 'pragmatic' outcomes, evidence was graded as very-low quality. None of the included studies provided useable data on our primary outcome 'tranquillisation or asleep' by 30 minutes, repeated need for tranquillisation or any economic outcomes. Data were available for our other main outcomes of agitation or aggression, needing restraint, and incidence of adverse effects.Risperidone versus haloperidol (up to 24 hours follow-up)For the outcome, specific behaviour - agitation, no clear difference was found between risperidone and haloperidol in terms of efficacy, measured as at least 50% reduction in the Positive and Negative Syndrome Scale - Psychotic Agitation Sub-score (PANSS-PAS) (RR 1.04, 95% CI 0.86 to 1.26; participants = 124; studies = 1; very low-quality evidence) and no effect was observed for need to use restraints (RR 2.00, 95% CI 0.43 to 9.21; participants = 28; studies = 1; very low-quality evidence). Incidence of adverse effects was similar between treatment groups (RR 0.94, 95% CI 0.54 to 1.66; participants = 124; studies = 1; very low-quality evidence).Risperidone versus olanzapineOne small trial (n = 29) reported useable data for the comparison risperidone versus olanzapine. No effect was observed for agitation measured as PANSS-PAS endpoint score at two hours (MD 2.50, 95% CI -2.46 to 7.46; very low-quality evidence); need to use restraints at four days (RR 1.43, 95% CI 0.39 to 5.28; very-low quality evidence); specific movement disorders measured as Behavioural Activity Rating Scale (BARS) endpoint score at four days (MD 0.20, 95% CI -0.43 to 0.83; very low-quality evidence).Risperidone versus quetiapineOne trial reported (n = 40) useable data for the comparison risperidone versus quetiapine. Aggression was measured using the Modified Overt Aggression Scale (MOAS) endpoint score at two weeks. A clear difference, favouring quetiapine was observed (MD 1.80, 95% CI 0.20 to 3.40; very-low quality evidence). No evidence of a difference between treatment groups could be observed for incidence of akathisia after 24 hours (RR 1.67, 95% CI 0.46 to 6.06; very low-quality evidence). Two participants allocated to risperidone and one allocated to quetiapine experienced myocardial ischaemia during the trial.Risperidone versus risperidone + oxcarbazepineOne trial (n = 68) measured agitation using the Positive and Negative Syndrome Scale - Excited Component.(PANSS-EC) endpoint score and found a clear difference, favouring the combination treatment at one week (MD 2.70, 95% CI 0.42 to 4.98; very low-quality evidence), but no effect was observed for global state using Clinical Global Impression - Improvement (CGI-I) endpoint score at one week (MD -0.20, 95% CI -0.61 to 0.21; very-low quality evidence). Incidence of extrapyramidal symptoms after 24 hours was similar between treatment groups (RR 1.59, 95% CI 0.49 to 5.14; very-low quality evidence).Risperidone versus risperidone + valproic acidTwo trials compared risperidone with a combination of risperidone plus valproic acid. No clear differences between the treatment groups were observed for aggression (MOAS endpoint score at three days: MD 1.07, 95% CI -0.20 to 2.34; participants = 54; studies = 1; very low-quality evidence) or incidence of akathisia after 24 hours: RR 0.75, 95% CI 0.28 to 2.03; participants = 122; studies = 2; very low-quality evidence).

AUTHORS' CONCLUSIONS

Overall, results for the main outcomes show no real effect for risperidone. The only data available for use in this review are from nine under-sampled trials and the evidence available is of very low quality. This casts uncertainty on the role of risperidone in rapid tranquillisation for people with psychosis-induced aggression. High-quality pragmatic RCTs are feasible and are needed before clear recommendations can be drawn on the use of risperidone for psychosis-induced aggression or agitation.

Randomized trial of betahistine mesilate tablets as augmentation for oxcarbazepine and carbamazepine in treating vestibular paroxysmia

Background

Vestibular paroxysmia (VP) is a rare episodic peripheral vestibular disorder. This study was conducted to compare the efficacy and acceptability of carbamazepine (CBZ) plus betahistine mesilate tablets (BMT) (CBZ+BMT) and oxcarbazepine (OXC) plus BMT (OXC+BMT) in treating VP, and investigated whether the synergistic effect could be increased along with the increased dose of BMT.

Methods

VP patients were recruited and randomly assigned to receive CBZ+BMT or OXC+BMT. The doses of CBZ and OXC were set to 200 and 300 mg/time, twice daily, respectively. The doses of BMT were set to 12 and 18 mg/time, twice daily. Half of the patients in each group received BMT 12 mg/time and the other half received BMT 18 mg/time. The treatment was continued for 12 weeks. The vertigo frequency, vertigo score, vertigo duration, response rate, and drug-related side effects were analyzed.

Results

In total, 92 patients in the CBZ+BMT group and 93 patients in the OXC+BMT group completed this trial. After 12 weeks of treatment, the two groups had similar average vertigo frequency, average vertigo score, average vertigo duration, and response rate. But the incidence of side effects was significantly higher in the CBZ+BMT group than in the OXC+BMT group (p=0.04). Subgroup analysis found that patients receiving BMT (18 mg) had greater reductions in average vertigo frequency, average vertigo duration, and average vertigo score, and higher response rates than patients receiving BMT (12 mg).

Conclusion

These results demonstrated that OXC+BMT may be suitable as an alternative method in VP patients with CBZ hypersensitivity, and the synergistic effect could be increased along with the increased dose of BMT.

Reversible splenial lesion syndrome due to oxcarbazepine withdrawal: case report and literature review

Background

Reversible splenial lesion syndrome is a distinct entity radiologically characterized by a reversible lesion in the splenium of the corpus callosum. According to previous reports, this condition may be associated with antiepileptic drug use or withdrawal. We herein report a case of reversible splenial lesion syndrome associated with oxcarbazepine withdrawal.

Case Report

A 39-year-old man presented with an 8-year history of epileptic seizures. During the previous 3 years, he had taken oxcarbazepine irregularly. One week prior to admission, he withdrew the oxcarbazepine on his own, and the epilepsy became aggravated. Magnetic resonance imaging (MRI) revealed an isolated lesion in the splenium of the corpus callosum with slight hypointensity on T1-weighted imaging and slight hyperintensity on T2-weighted imaging. Regular oxcarbazepine was prescribed. Over a 5-month follow-up period, repeat MRI showed that the abnormal signals in the splenium of the corpus callosum had completely disappeared.

Conclusion

Reversible splenial lesion syndrome is a rare clinicoradiological disorder that can resolve spontaneously with a favorable outcome. Clinicians should be aware of this condition and that oxcarbazepine withdrawal is a possible etiological factor.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data

BACKGROUND

Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment. Most people with epilepsy are treated with a single antiepileptic drug (monotherapy) and current guidelines from the National Institute for Health and Care Excellence (NICE) in the United Kingdom for adults and children recommend carbamazepine or lamotrigine as first-line treatment for partial onset seizures and sodium valproate for generalised onset seizures; however a range of other antiepileptic drug (AED) treatments are available, and evidence is needed regarding their comparative effectiveness in order to inform treatment choices.

OBJECTIVES

To compare the time to withdrawal of allocated treatment, remission and first seizure of 10 AEDs (carbamazepine, phenytoin, sodium valproate, phenobarbitone, oxcarbazepine, lamotrigine, gabapentin, topiramate, levetiracetam, zonisamide) currently used as monotherapy in children and adults with partial onset seizures (simple partial, complex partial or secondary generalised) or generalised tonic-clonic seizures with or without other generalised seizure types (absence, myoclonus).

SEARCH METHODS

We searched the following databases: Cochrane Epilepsy's Specialised Register, CENTRAL, MEDLINE and SCOPUS, and two clinical trials registers. We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field. The date of the most recent search was 27 July 2016.

SELECTION CRITERIA

We included randomised controlled trials of a monotherapy design in adults or children with partial onset seizures or generalised onset tonic-clonic seizures (with or without other generalised seizure types).

DATA COLLECTION AND ANALYSIS

This was an individual participant data (IPD) review and network meta-analysis. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', 'time to first seizure post-randomisation', and 'occurrence of adverse events'. We presented all time-to-event outcomes as Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs). We performed pairwise meta-analysis of head-to-head comparisons between drugs within trials to obtain 'direct' treatment effect estimates and we performed frequentist network meta-analysis to combine direct evidence with indirect evidence across the treatment network of 10 drugs. We investigated inconsistency between direct estimates and network meta-analysis via node splitting. Due to variability in methods and detail of reporting adverse events, we have not performed an analysis. We have provided a narrative summary of the most commonly reported adverse events.

MAIN RESULTS

IPD was provided for at least one outcome of this review for 12,391 out of a total of 17,961 eligible participants (69% of total data) from 36 out of the 77 eligible trials (47% of total trials). We could not include IPD from the remaining 41 trials in analysis for a variety of reasons, such as being unable to contact an author or sponsor to request data, data being lost or no longer available, cost and resources required to prepare data being prohibitive, or local authority or country-specific restrictions.We were able to calculate direct treatment effect estimates for between half and two thirds of comparisons across the outcomes of the review, however for many of the comparisons, data were contributed by only a single trial or by a small number of participants, so confidence intervals of estimates were wide.Network meta-analysis showed that for the primary outcome 'Time to withdrawal of allocated treatment,' for individuals with partial seizures; levetiracetam performed (statistically) significantly better than current first-line treatment carbamazepine and other current first-line treatment lamotrigine performed better than all other treatments (aside from levetiracetam); carbamazepine performed significantly better than gabapentin and phenobarbitone (high-quality evidence). For individuals with generalised onset seizures, first-line treatment sodium valproate performed significantly better than carbamazepine, topiramate and phenobarbitone (moderate- to high-quality evidence). Furthermore, for both partial and generalised onset seizures, the earliest licenced treatment, phenobarbitone seems to perform worse than all other treatments (moderate- to high-quality evidence).Network meta-analysis also showed that for secondary outcomes 'Time to 12-month remission of seizures' and 'Time to six-month remission of seizures,' few notable differences were shown for either partial or generalised seizure types (moderate- to high-quality evidence). For secondary outcome 'Time to first seizure,' for individuals with partial seizures; phenobarbitone performed significantly better than both current first-line treatments carbamazepine and lamotrigine; carbamazepine performed significantly better than sodium valproate, gabapentin and lamotrigine. Phenytoin also performed significantly better than lamotrigine (high-quality evidence). In general, the earliest licenced treatments (phenytoin and phenobarbitone) performed better than the other treatments for both seizure types (moderate- to high-quality evidence).Generally, direct evidence and network meta-analysis estimates (direct plus indirect evidence) were numerically similar and consistent with confidence intervals of effect sizes overlapping.The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness and rash or skin disorders.

AUTHORS' CONCLUSIONS

Overall, the high-quality evidence provided by this review supports current guidance (e.g. NICE) that carbamazepine and lamotrigine are suitable first-line treatments for individuals with partial onset seizures and also demonstrates that levetiracetam may be a suitable alternative. High-quality evidence from this review also supports the use of sodium valproate as the first-line treatment for individuals with generalised tonic-clonic seizures (with or without other generalised seizure types) and also demonstrates that lamotrigine and levetiracetam would be suitable alternatives to either of these first-line treatments, particularly for those of childbearing potential, for whom sodium valproate may not be an appropriate treatment option due to teratogenicity.

Flow cytometric examination of apoptotic effect on brain tissue in postnatal period created by intrauterine oxcarbazepine and gabapentin exposure

OBJECTIVE

For epileptics, pregnancy contains the balance between no seizure period and antiepileptic use having the least teratogenicity risk. The purpose is to analyse with flow cytometry the apoptotic effects on postnatal brain tissue caused by prenatal use of second generation antiepileptics oxcarbazepine (OXC) and gabapentin (GBP) having different effect mechanisms.

METHOD

30 (n = 5 each group) Wistar albino male rats (45-days-old) are used. First 3 groups are exposed to OXC (100 mg/kg/day), GBP (50 mg/kg/day), and saline, respectively on the 1st-5th prenatal days (preimplantation-implantation period) while the second 3 groups are exposed to the same substances on the 6th-15th prenatal days (organogenesis), respectively. After sacrifice, brain tissue samples were made into suspension with mechanic and enzymatic digestion and examined with flow cytometry.

RESULTS

While apoptosis rate appeared high in rats exposed to OXC on the 1st-5th (p < 0.001) and 6th-15th days (p < 0.001), no significant difference occurred for GBP (p = 0.004; p = 0.012) and saline (p = 0.012). Considering time effect in three treatment groups, while difference was not significant for PSS and GBP groups (p = 0.847 and p = 0.934), apoptosis rate was significantly high for OXC on the 6th-15th days compared to the 1st-5th days (p < 0.001).

CONCLUSION

It is observed that the use of OXC causes neurotoxicity during preimplantation, implantation and, especially, organogenesis period (neurogenesis) whereas GBP does not (Fig. 3, Ref. 32).

Oxcarbazepine for neuropathic pain

BACKGROUND

Several anticonvulsant drugs are used in the management of neuropathic pain. Oxcarbazepine is an anticonvulsant drug closely related to carbamazepine. Oxcarbazepine has been reported to be efficacious in the treatment of neuropathic pain, but evidence from randomised controlled trials (RCTs) is conflicting. Oxcarbazepine is reportedly better tolerated than carbamazepine. This is the first update of a review published in 2013.

OBJECTIVES

To assess the benefits and harms of oxcarbazepine for different types of neuropathic pain.

SEARCH METHODS

On 21 November 2016, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE and Embase. We searched the Chinese Biomedical Retrieval System (January 1978 to November 2016). We searched the US National Institutes of Health (NIH) databases and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials in January 2017, and we wrote to the companies who make oxcarbazepine and to pain experts requesting additional information.

SELECTION CRITERIA

All RCTs and randomised cross-over studies of oxcarbazepine for the treatment of people of any age or sex with any neuropathic pain were eligible. We planned to include trials of oxcarbazepine compared with placebo or any other intervention with a treatment duration of at least six weeks, regardless of administration route and dose.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Five multicentre, randomised, placebo-controlled, double-blind trials with a total of 862 participants were eligible for inclusion in this updated review. Three trials involved participants with painful diabetic peripheral neuropathy (DPN) (n = 634), one included people with neuropathic pain due to radiculopathy (n = 145), and one, which was newly identified at this update, involved participants with peripheral neuropathic pain of mixed origin (polyneuropathy, peripheral nerve injury or postherpetic neuralgia) (n = 83). Some studies did not report all outcomes of interest. For painful DPN, compared to the baseline, the proportion of participants who reported at least a 50% or 30% reduction of pain scores after 16 weeks of treatment in the oxcarbazepine group versus the placebo group were: at least 50% reduction: 34.8% with oxcarbazepine versus 18.2% with placebo (risk ratio (RR) 1.91, 95% confidence interval (CI) 1.08 to 3.39, number of people needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 3 to 41); and at least 30% reduction: 44.9% with oxcarbazepine versus 28.6% with placebo (RR 1.57, 95% CI 1.01 to 2.44; NNTB 6, 95% CI 3 to 114; n = 146). Both results were based on data from a single trial, since two trials that found little or no benefit did not provide data that could be included in a meta-analysis. Although these trials were well designed, incomplete outcome data and possible unblinding of participants due to obvious adverse effects placed the results at a high risk of bias. There was also serious imprecision and a high risk of publication bias. The radiculopathy trial reported no benefit for the outcome 'at least 50% pain relief' from oxcarbazepine. In mixed neuropathies, 19.3% of people receiving oxcarbazepine versus 4.8% receiving placebo had at least 50% pain relief. These small trials had low event rates and provided, at best, low-quality evidence for any outcome. The proportion of people with 'improved' or 'very much improved' pain was 45.9% with oxcarbazepine versus 30.1% with placebo in DPN (RR 1.46, 95% CI 1.13 to 1.88; n = 493; 2 trials; very-low-quality evidence) and 23.9% with oxcarbazepine versus 14.9% with placebo in radiculopathy (RR 1.61, 95% CI 0.81 to 3.20; n = 145).We found no trials in other types of neuropathic pain such as trigeminal neuralgia.Trial reports stated that most adverse effects were mild to moderate in severity. Based on moderate-quality evidence from the three DPN trials, serious adverse effects occurred in 8.3% with oxcarbazepine and 2.5% with placebo (RR 3.65, 95% CI 1.45 to 9.20; n = 634; moderate-quality evidence). The number needed to treat for an additional harmful (serious adverse effect) outcome (NNTH) was 17 (95% CI 11 to 42). The RR for serious adverse effects in the radiculopathy trial was 3.13 (95% CI 0.65 to 14.98, n = 145). The fifth trial did not provide data.More people withdrew because of adverse effects with oxcarbazepine than with placebo (DPN: 25.6% with oxcarbazepine versus 6.8% with placebo; RR 3.83, 95% CI 2.29 to 6.40; radiculopathy: 42.3% with oxcarbazepine versus 14.9% with placebo; RR 2.84, 95% CI 1.55 to 5.23; mixed neuropathic pain: 13.5% with oxcarbazepine versus 1.2% with placebo; RR 11.51, 95% CI 1.54 to 86.15).

AUTHORS' CONCLUSIONS

This review found little evidence to support the effectiveness of oxcarbazepine in painful diabetic neuropathy, neuropathic pain from radiculopathy and a mixture of neuropathies. Some very-low-quality evidence suggests efficacy but small trials, low event rates, heterogeneity in some measures and a high risk of publication bias means that we have very low confidence in the measures of effect. Adverse effects, serious adverse effects and adverse effects leading to discontinuation are probably more common with oxcarbazepine than placebo; however, the numbers of participants and event rates are low. More well-designed, multicentre RCTs investigating oxcarbazepine for various types of neuropathic pain are needed, and selective publication of studies or data should be avoided.

Carbamazepine 10,11-epoxidation in human liver microsomes: influence of the CYP3A5*3 polymorphism

Carbamazepine (CBZ) is a commonly prescribed antiepileptic drug, and is mainly metabolized to 10,11-CBZ epoxide in humans. Its biotransformation is catalyzed by cytochrome P450 (CYP) enzymes, with the predominant isoforms being CYP3A4 and CYP3A5. In the present study, the effects of the CYP3A5*3 (rs776746) polymorphism on CBZ 10,11-epoxidation in human liver microsomes genotyped as CYP3A5*3 were examined using a kinetic analysis. The kinetics for CBZ 10,11-epoxidation fit the Hill model with n of approximately 1.9-2.1 in all liver microsomes of the wild-type (CYP3A5*1/*1) and heterozygous (CYP3A5*1/*3) and homozygous (CYP3A5*3/*3) variants. The S50, Vmax, and CLmax values of wild-type liver microsomes were 263-327 μM, 793-1590 pmol/min/mg protein, and 1.51-2.95 μL/min/mg protein, respectively. The Vmax and CLmax values of liver microsomes of the heterozygous variant were approximately 15-40% those of wild-type liver microsomes. On the other hand, the Vmax and CLmax values of liver microsomes of the homozygous variant were more similar to those of the wild-type than the heterozygous variant. These results suggest that the CYP3A5*3 polymorphism has a negligible effect on CBZ 10,11-epoxidation in an in vitro system using human liver microsomes.

A randomized double-blind, placebo-controlled, cross-over trial (Vestparoxy) of the treatment of vestibular paroxysmia with oxcarbazepine

Objective

Vestibular paroxysmia (VP) is characterized by short, often oligosymptomatic attacks of vertigo which occur spontaneously or are sometimes provoked by turning the head. Despite the description of the disease almost 40 years ago (first termed “disabling positional vertigo”), no controlled treatment trial has been published to date. The Vestparoxy trial was designed as a randomized, placebo-controlled, double-blind cross-over trial to examine the therapeutic effect of oxcarbazepine (OXA) in patients with definite or probable VP.

Methods

Patients were recruited from August 2005 to December 2011 in the outpatient Dizziness Unit of the Department of Neurology of the Munich University Hospital, and randomized to receive OXA (first week: 300 mg once per day, second week: 300 mg b.i.d., third week: 300 mg t.i.d. until the end of the third month), followed by placebo or vice versa with a 1-month wash-out period in between. The primary endpoint was the number of days with one or more attacks. Secondary endpoints were the number of attacks during the observed days, and the median (for each day) duration of attacks. All these endpoints were assessed using standardized diaries collected at the end of each treatment phase.

Results

Forty-three patients were randomized, 18 patients provided usable data (2525 patient days) for at least one treatment phase and were included in the main (intention-to-treat) analysis. The most common reasons for discontinuation documented were adverse events. The risk of experiencing a day with at least one attack was 0.41 under OXA, and 0.62 under placebo treatment, yielding a relative risk of 0.67 (95% CI 0.47–0.95, p = 0.025). The number of attacks during the observed days ratio was 0.53 (95% CI 0.42–0.68, p < 0.001) under OXA compared to placebo. Median attack duration was 4 s (Q25: 2 s, Q75: 120 s) under OXA, and 3 s (Q25: 2 s, Q75: 60 s) under placebo treatment. When days with no attacks, i.e., duration = 0, were included in the analysis, these figures changed to 0 (Q25: 0, Q75: 3 s), and 2 (Q25: 0, Q75: 6 s). No serious adverse events or new safety findings were identified during the trial.

Conclusions

The Vestparoxy trial showed a significant reduction of VP attacks under OXA compared to placebo treatment, confirming the known and revealing no new side effects.

Population pharmacokinetics of oxcarbazepine and its metabolite 10-hydroxycarbazepine in healthy subjects

Oxcarbazepine is indicated for the treatment of partial or generalised tonic-clonic seizures. Most of the absorbed oxcarbazepine is converted into its active metabolite, 10-hydroxycarbazepine (MHD), which can exist as R-(-)- and S-(+)-MHD enantiomers. Here we describe the influence of the P-glycoprotein (P-gp) inhibitor verapamil, on the disposition of oxcarbazepine and MHD enantiomers, both of which are P-gp substrates. Healthy subjects (n=12) were randomised to oxcarbazepine or oxcarbazepine combined with verapamil at doses of 300mg b.i.d. and 80mg t.i.d., respectively. Blood samples (n=185) were collected over a period of 12h post oxcarbazepine dose. An integrated PK model was developed using nonlinear mixed effects modelling using a meta-analytical approach. The pharmacokinetics of oxcarbazepine was described by a two-compartment model with absorption transit compartments and first-order elimination. The concentration-time profiles of both MHD enantiomers were characterised by a one-compartment distribution model. Clearance estimates (95% CI) were 84.9L/h (69.5-100.3) for oxcarbazepine and 2.0L/h (1.9-2.1) for both MHD enantiomers. The volume of distribution was much larger for oxcarbazepine (131L (97-165)) as compared to R-(-)- and S-(+)-MHD (23.6L (14.4-32.8) vs. 31.7L (22.5-40.9), respectively). Co-administration of verapamil resulted in a modest increase of the apparent bioavailability of oxcarbazepine by 12% (10-28), but did not affect parent or metabolite clearances. Despite the evidence of comparable systemic levels of OXC and MHD following administration of verapamil, differences in brain exposure to both moieties cannot be excluded after P-glycoprotein inhibition.

Improved in vitro and in vivo performance of carbamazepine enabled by using a succinic acid cocrystal in a stable suspension formulation

Currently cocrystals are considered as an established approach for making crystalline solids with overall improved physico-chemical properties. However, some otherwise well behaving cocrystals undergo rapid dissociation during dissolution, with ultimate conversion to parent drug and thus apparent loss of improved solubility. The polymeric carriers are long known to manipulate this conversion during dissolution to parent crystalline drug, which may hinder or accelerate the dissolution process if used in a dosage form. The goal of this study was to deliver in vivo a more soluble carbamazepine-succinic acid (CBZ-SUC) cocrystal in suspension formulation utilizing Hydroxypropyl methyl cellulose (HPMC-AS) as a crystallization inhibitor and Polyvinyl carpolactam-polyvinyl acetate-polyethylene glycol graft copolymer ® as solubilizer. The concentration of these polymers were systemically varied during in vitro dissolution studies, while selected formulations from dissolution studies were tested in vivo. Pharmacokinetic studies (PK) in rabbits demonstrated that formulation F7-X (1% cocrystal, 1% HPMC-AS and 2% Polyvinyl carpolactam-polyvinyl acetatepolyethylene glycol graft co-polymer®) caused almost 6fold improvement in AUC0-72 (***P k 0.05) as well as much higher C_max of 4.73μ.mL-1 to that of 1.07μ.mL-1 of unformulated 'neat' cocrystal given orally. When reference formulation of CBZ (F5-X) with similar composition to F7-X were given to rabbits, cocrystal formulation gave 1.37fold (***P k 0.05) bioavailability than CBZ reference formulation. C_max of reference formulation observed was 3.9μmL-1.

Comparative safety of antiepileptic drugs for neurological development in children exposed during pregnancy and breast feeding: a systematic review and network meta-analysis

OBJECTIVES

Compare the safety of antiepileptic drugs (AEDs) on neurodevelopment of infants/children exposed in utero or during breast feeding.

DESIGN AND SETTING

Systematic review and Bayesian random-effects network meta-analysis (NMA). MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched until 27 April 2017. Screening, data abstraction and quality appraisal were completed in duplicate by independent reviewers.

PARTICIPANTS

29 cohort studies including 5100 infants/children.

INTERVENTIONS

Monotherapy and polytherapy AEDs including first-generation (carbamazepine, clobazam, clonazepam, ethosuximide, phenobarbital, phenytoin, primidone, valproate) and newer-generation (gabapentin, lamotrigine, levetiracetam, oxcarbazepine, topiramate, vigabatrin) AEDs. Epileptic women who did not receive AEDs during pregnancy or breast feeding served as the control group.

PRIMARY AND SECONDARY OUTCOME MEASURES

Cognitive developmental delay and autism/dyspraxia were primary outcomes. Attention-deficit hyperactivity disorder, language delay, neonatal seizures, psychomotor developmental delay and social impairment were secondary outcomes.

RESULTS

The NMA on cognitive developmental delay (11 cohort studies, 933 children, 18 treatments) suggested that among all AEDs only valproate was statistically significantly associated with more children experiencing cognitive developmental delay compared with control (OR=7.40, 95% credible interval (CrI) 3.00 to 18.46). The NMA on autism (5 cohort studies, 2551 children, 12 treatments) suggested that oxcarbazepine (OR 13.51, CrI 1.28 to 221.40), valproate (OR 17.29, 95% CrI 2.40 to 217.60), lamotrigine (OR 8.88, CrI 1.28 to 112.00) and lamotrigine+valproate (OR 132.70, CrI 7.41 to 3851.00) were associated with significantly greater odds of developing autism compared with control. The NMA on psychomotor developmental delay (11 cohort studies, 1145 children, 18 treatments) found that valproate (OR 4.16, CrI 2.04 to 8.75) and carbamazepine+phenobarbital+valproate (OR 19.12, CrI 1.49 to 337.50) were associated with significantly greater odds of psychomotor delay compared with control.

CONCLUSIONS

Valproate alone or combined with another AED is associated with the greatest odds of adverse neurodevelopmental outcomes compared with control. Oxcarbazepine and lamotrigine were associated with increased occurrence of autism. Counselling is advised for women considering pregnancy to tailor the safest regimen.

TRIAL REGISTRATION NUMBER

PROSPERO database (CRD42014008925).

Determination of carbamazepine and 12 degradation products in various compartments of an outdoor aquatic mesocosm by reliable analytical methods based on liquid chromatography-tandem mass spectrometry

The aims of this work are to develop suitable analytical methods to determine the widely used anticonvulsant carbamazepine and 12 of its degradation/transformation products in water, sediment, fish (Gasterosteus aculeatus) and mollusc (Dreissena polymorpha). Protocols based on solid phase extraction for water, pressurized-liquid extraction for sediments and QuEChERS (quick easy cheap efficient rugged and safe) extraction for both organisms followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) are developed, validated and finally applied to samples collected during a 6-month experiment in outdoor mesocosms. Very low detection limits are reached, allowing environmentally realistic doses (namely, 0.05, 0.5 and 5 μg/L nominal concentrations) to be employed. The results indicate several metabolites and/or transformation products in each compartment investigated, with concentrations sometimes being greater than that of the parent carbamazepine. Biotic degradation of carbamazepine is demonstrated in water, leading to 10,11-dihydrocarbamazepine and 10,11-epoxycarbamazepine. In sediment, the degradation results in the formation of acridine, and 2- and 3-hydroxycarbamazepine. Finally, in both organisms, a moderate bioaccumulation is observed together with a metabolization leading to 10,11-epoxycarbamazepine in fish and 2-hydroxycarbamazepine in mollusc. Acridone is also present in fish. This study provides new and interesting data, helping to elucidate how chronic exposure to carbamazepine at relevant concentrations may affect impact freshwater ecosystems.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data

BACKGROUND

Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment. Most people with epilepsy are treated with a single antiepileptic drug (monotherapy) and current guidelines from the National Institute for Health and Care Excellence (NICE) in the United Kingdom for adults and children recommend carbamazepine or lamotrigine as first-line treatment for partial onset seizures and sodium valproate for generalised onset seizures; however a range of other antiepileptic drug (AED) treatments are available, and evidence is needed regarding their comparative effectiveness in order to inform treatment choices.

OBJECTIVES

To compare the time to withdrawal of allocated treatment, remission and first seizure of 10 AEDs (carbamazepine, phenytoin, sodium valproate, phenobarbitone, oxcarbazepine, lamotrigine, gabapentin, topiramate, levetiracetam, zonisamide) currently used as monotherapy in children and adults with partial onset seizures (simple partial, complex partial or secondary generalised) or generalised tonic-clonic seizures with or without other generalised seizure types (absence, myoclonus).

SEARCH METHODS

We searched the following databases: Cochrane Epilepsy's Specialised Register, CENTRAL, MEDLINE and SCOPUS, and two clinical trials registers. We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field. The date of the most recent search was 27 July 2016.

SELECTION CRITERIA

We included randomised controlled trials of a monotherapy design in adults or children with partial onset seizures or generalised onset tonic-clonic seizures (with or without other generalised seizure types).

DATA COLLECTION AND ANALYSIS

This was an individual participant data (IPD) review and network meta-analysis. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', 'time to first seizure post-randomisation', and 'occurrence of adverse events'. We presented all time-to-event outcomes as Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs). We performed pairwise meta-analysis of head-to-head comparisons between drugs within trials to obtain 'direct' treatment effect estimates and we performed frequentist network meta-analysis to combine direct evidence with indirect evidence across the treatment network of 10 drugs. We investigated inconsistency between direct estimates and network meta-analysis via node splitting. Due to variability in methods and detail of reporting adverse events, we have not performed an analysis. We have provided a narrative summary of the most commonly reported adverse events.

MAIN RESULTS

IPD was provided for at least one outcome of this review for 12,391 out of a total of 17,961 eligible participants (69% of total data) from 36 out of the 77 eligible trials (47% of total trials). We could not include IPD from the remaining 41 trials in analysis for a variety of reasons, such as being unable to contact an author or sponsor to request data, data being lost or no longer available, cost and resources required to prepare data being prohibitive, or local authority or country-specific restrictions.We were able to calculate direct treatment effect estimates for between half and two thirds of comparisons across the outcomes of the review, however for many of the comparisons, data were contributed by only a single trial or by a small number of participants, so confidence intervals of estimates were wide.Network meta-analysis showed that for the primary outcome 'Time to withdrawal of allocated treatment,' for individuals with partial seizures; levetiracetam performed (statistically) significantly better than both current first-line treatments carbamazepine and lamotrigine; lamotrigine performed better than all other treatments (aside from levetiracetam), and carbamazepine performed significantly better than gabapentin and phenobarbitone (high-quality evidence). For individuals with generalised onset seizures, first-line treatment sodium valproate performed significantly better than carbamazepine, topiramate and phenobarbitone (moderate- to high-quality evidence). Furthermore, for both partial and generalised onset seizures, the earliest licenced treatment, phenobarbitone seems to perform worse than all other treatments (moderate- to high-quality evidence).Network meta-analysis also showed that for secondary outcomes 'Time to 12-month remission of seizures' and 'Time to six-month remission of seizures,' few notable differences were shown for either partial or generalised seizure types (moderate- to high-quality evidence). For secondary outcome 'Time to first seizure,' for individuals with partial seizures; phenobarbitone performed significantly better than both current first-line treatments carbamazepine and lamotrigine; carbamazepine performed significantly better than sodium valproate, gabapentin and lamotrigine. Phenytoin also performed significantly better than lamotrigine (high-quality evidence). In general, the earliest licenced treatments (phenytoin and phenobarbitone) performed better than the other treatments for both seizure types (moderate- to high-quality evidence).Generally, direct evidence and network meta-analysis estimates (direct plus indirect evidence) were numerically similar and consistent with confidence intervals of effect sizes overlapping.The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness and rash or skin disorders.

AUTHORS' CONCLUSIONS

Overall, the high-quality evidence provided by this review supports current guidance (e.g. NICE) that carbamazepine and lamotrigine are suitable first-line treatments for individuals with partial onset seizures and also demonstrates that levetiracetam may be a suitable alternative. High-quality evidence from this review also supports the use of sodium valproate as the first-line treatment for individuals with generalised tonic-clonic seizures (with or without other generalised seizure types) and also demonstrates that lamotrigine and levetiracetam would be suitable alternatives to either of these first-line treatments, particularly for those of childbearing potential, for whom sodium valproate may not be an appropriate treatment option due to teratogenicity.

Influence of the dual combination of silymarin and (-)-epigallocatechin gallate, natural dietary flavonoids, on the pharmacokinetics of oxcarbazepine in rats

Considering the potential of flavonoids in reversing the P-glycoprotein (P-gp)-mediated multidrug resistance, this work aimed to assess the combined effects of silymarin and (-)-epigallocatechin gallate (EPG) on the pharmacokinetics of the P-gp substrates oxcarbazepine (OXC) and licarbazepine (LIC). Rats were pre-treated intraperitoneally with silymarin (25 mg/kg), EPG (25 mg/kg), silymarin/EPG (12.5/12.5 mg/kg; 6.25/18.75 mg/kg; 18.75/6.25 mg/kg) or verapamil (25 mg/kg, reference P-gp inhibitor) before the intraperitoneal administration of OXC (50 mg/kg). Pre-treatment with dual silymarin/EPG combinations originated peak plasma concentrations of OXC and LIC (pharmacologically active metabolite of OXC) similar to those achieved in the presence of verapamil (positive control). Moreover, the effects promoted by silymarin/EPG combinations on the magnitude of systemic drug exposure to OXC and LIC were also reflected in the corresponding drug levels attained in the brain (biophase). These findings evidence the synergistic effect of silymarin and EPG in enhancing the degree of systemic exposure to OXC and LIC in rats, which occurred in a comparable extent to that observed with verapamil. Hence, our findings support the combination of flavonoid-type P-gp inhibitors and P-gp substrate antiepileptic drugs as a potential therapeutic strategy for the management of pharmacoresistant epilepsy.

Investigation and risk evaluation of the occurrence of carbamazepine, oxcarbazepine, their human metabolites and transformation products in the urban water cycle

Trace organic contaminants such as pharmaceuticals, personal care products and industrial chemicals are frequently detected in the urban water cycle, including wastewater, surface water and groundwater, as well as drinking water. These also include human metabolites (HMs), which are formed in the human body and then excreted via urine or feces, as well as transformation products (TPs) formed in engineered treatment systems and the aquatic environment. In the current study, the occurrence of HMs as well as their TPs of the anticonvulsants carbamazepine (CBZ) and oxcarbazepine (OXC) were investigated using LC tandem MS in effluents of wastewater treatment plants (WWTPs), surface water and groundwater. Highest concentrations were observed in raw wastewater for 10,11-dihydro-10,11-dihydroxycarbamazepine (DiOHCBZ), 10,11-dihydro-10-hydroxy-cabamazepine (10OHCBZ) and CBZ with concentrations ranging up to 2.7 ± 0.4, 1.7 ± 0.2 and 1.07 ± 0.06 μg L^-1, respectively. Predictions of different toxicity endpoints using a Distributed Structure-Searchable Toxicity (DSSTox) expert system query indicated that several HMs and TPs, in particular 9-carboxy-acridine (9-CA-ADIN) and acridone (ADON), may exhibit an increased genotoxicity compared to the parent compound CBZ. As 9-CA-ADIN was also detected in groundwater, a detailed investigation of the genotoxicity of 9-CA-ADIN is warranted. Investigations of an advanced wastewater treatment plant further revealed that the discharge of the investigated compounds into the aquatic environment could be substantially reduced by ozonation followed by granular activated carbon (GAC) filtration.

An investigation of the characteristics of outpatients with epilepsy and antiepileptic drug utilization in a multicenter cross-sectional study in China

OBJECTIVES

This study aimed to describe the distribution of seizure types, clinical characteristics, and antiepileptic drug (AED) utilization in patients with epilepsy visiting tertiary hospitals in China.

METHODS

This was an observational, cross-sectional epidemiology study conducted at 11 tertiary hospitals across China from May 2014 to November 2014. A total of 1603 patients, of either sex or any age with confirmed diagnosis of epilepsy, visiting outpatient clinics at tertiary hospitals were screened and enrolled. Demographics, seizure types, frequency, etiologies, comorbidities, and current AED therapy were analyzed using descriptive statistics.

RESULTS

Overall, the majority (n=1201; 74.9%) of patients were adults (16-59years of age), and the mean (SD) age was 27.5 (15.9) years. A total of 989 (61.7%) patients had partial seizures, and 653 (40.7%) had generalized seizures. The majority experienced monthly (n=663) or yearly (n=625) seizures, with 2.7seizures/month or 2.9seizures/year, respectively. The most commonly reported symptomatic etiologies were traumatic brain injury, encephalitis, and stroke, whereas the most common comorbidities were sleep disorder, headache, anxiety, and depression. Overall, monotherapy was used in 54.1% of patients, while 30.6% of patients used dual therapy. The most commonly prescribed monotherapy for patients with partial seizures was oxcarbazepine (25.9%), while that for patients with generalized seizures was valproic acid (38.9%), and the most common AED combination was valproic acid and lamotrigine. Overall, valproic acid was the most commonly prescribed AED as monotherapy and combination therapy.

CONCLUSION

Findings from this study provide extensive information on clinical characteristics and utilization of AEDs in Chinese patients with epilepsy which may help physicians make well-informed clinical decisions.

Manic espisode, confusional syndrome and reversible splenial lesion after abrupt withdrawal of oxcarbazepine

BACKGROUND

Anticonvulsants are considered a second line option for bipolar disorder, it is known that the abrupt withdrawal is rarely related with demyelinated lesions of the splenium of the corpus callosum. Oxcarbazepine is used in bipolar disorder although it is not stated in the data sheet.

CLINICAL CASE

We presented a case of a 50 years old woman with bipolar disorder who is treated with lithium and oxcarbazepine, she presented a manic episode and a confusional syndrome after she stopped taking the medication. The magnetic resonance showed a restricted diffusion area at the splenium of the corpus callosum and bifrontal hygromas that disappear two weeks later.

CONCLUSIONS

The results of this study suggest that for a patient presenting with a mild encephalopathy and reversible splenial lesion, one should consider whether it is related to withdrawal of oxcarbazepine.

COLOCASIA ESCULENTA CORMS MUCILAGE-ALGINATE MICROSPHERES OF OXCARBAZEPINE: DESIGN, OPTIMIZATION AND EVALUATION

The present investigation was undertaken with an objective of formulating sustained release microspheres of oxcarbazepine (OXC), an anti-epileptic drug, to overcome poor patient compliance and exposure to high doses associated with currently marketed OXC dosage forms. Ionic gelation technique was used to prepare OXC microspheres by using sodium alginate along with rate controlling polymer Colocasia esculenta mucilage (CEM) matrix as well coated form. The microspheres have been characterized by differential scanning calorimetry (DSC) for understanding thermal stability and Fourier transform infrared (FT-IR) spectroscopy to investigate the chemical interaction as well as to assess the structure of drug-loaded formulation. Surface morphology of the microspheres was investigated by scanning electron microscope (SEM). The size distribution of OXC microspheres as studied by optical microscopy was in the range of 394-575 pm. The microspheres exhibited encapsulating efficiency from 75 to 92%. The release of drug from the microspheres at pH 1.2 is negligible. Under neutral conditions, the microspheres were swell and release was attributed mainly to polymer relaxation. The release pattern from microspheres followed Korsmeyer-Peppas model and the value of n > 1 showed that drug released by anomalous (non-Fickian) diffusion. The data obtained thus suggest that a microparticulate system can be successfully designed by using CEM with alginate for sustained delivery of OXC.

Prenatal exposure to antiepileptic drugs and use of primary healthcare during childhood: a population-based cohort study in Denmark

OBJECTIVE

Prenatal exposure to antiepileptic drugs (AEDs) has been associated with adverse outcomes in the offspring such as congenital malformations and neuropsychiatric disorders. The objective of this study was to investigate whether prenatal exposure to AEDs is also associated with more frequent use of primary healthcare during childhood.

DESIGN

Population-based cohort study.

SETTING

Nationwide national registers in Denmark.

PARTICIPANTS

All live-born singletons in Denmark during 1997-2012 identified in the Danish National Patient Register and followed until 31 December 2013 (n=963 010). Information on prenatal exposure to AEDs for maternal indication of epilepsy and other neurological conditions was obtained from the Danish Register of Medicinal Product Statistics.

MAIN OUTCOME MEASURES

The primary outcome measure was the number and type of contacts with the general practitioner (GP), excluding routine well-child visits and vaccinations. The secondary outcome measure was specific services provided at the GP contact. The association between prenatal exposure to AEDs and contacts with the GP was estimated by using negative binomial regression adjusting for sex and date of birth of the child, maternal age, cohabitation status, income, education, substance abuse, depression, severe psychiatric disorders and use of antipsychotics, antidepressants and insulin.

RESULTS

Children exposed prenatally to AEDs (n=4478) had 3% (95% CI 0 to 5%) more GP contacts during the study period than unexposed children. This was primarily accounted for by the number of phone contacts. Within each year of follow-up, exposed children tended to have more contacts than unexposed children, but the differences were small. We found no difference between exposed and unexposed children with regard to specific services provided at the GP contact. For the individual AEDs, we found that exposure to valproate or oxcarbazepine was associated with more GP contacts.

CONCLUSIONS

We found only minor differences between prenatally AED-exposed and unexposed children in the number of GP contacts.

Clinical features of benign epilepsy of childhood with centrotemporal spikes in chinese children

This multicenter clinical trial was conducted to examine current practice of benign epilepsy with centrotemporal spikes and especially address the question that in what circumstances 1 antiepileptic drug (AED) should be preferred.Twenty-five medical centers participate in this clinical trial. The general information, clinical information, and treatment status were collected under the guidance of clinicians and then analyzed. Difference between different treatment groups was compared, and usefulness of the most commonly used AEDs was evaluated.A total of 1817 subjects were collected. The average age of the subject was 8.81 years. The average age of onset is 6.85 years (1-14 years). Male-to-female ratio is 1.13:1. A total of 62.9% of the patients are receiving monotherapies, and 10.6% are receiving multidrug therapy. Both age and course of disease of treated rolandic epilepsy (RE) patients are significantly different from those of untreated patients. Bilateral findings on electroencephalography (EEG) are less seen in patients with monotherapy compared with patients with multidrug therapy. Except for 25.4% patients not taking any AEDs, oxcarbazepine (OXC), sodium valproate (VPA), and levetiracetam (LEV) are the most commonly used 3 AEDs. VPA and LEV are commonly used in add-on therapy. OXC and LEV are more effective as monotherapy than VPA.Age of onset of Chinese RE patients is 6.85 years. Bilateral findings on EEG could be a risk factor to require multidrug therapy. In Chinese patients, OXC, VPA, and LEV are most commonly used AEDs as monotherapy and OXC and LEV are more effective than VPA.

Effects of UGT1A9 genetic polymorphisms on monohydroxylated derivative of oxcarbazepine concentrations and oxcarbazepine monotherapeutic efficacy in Chinese patients with epilepsy

AIM

The human UDP-glucuronosyltransferase which is genetically polymorphic catalyzes glucuronidations of various drugs. The interactions among UGT1A4, UGT1A6, UGT1A9, and UGT2B15 genetic polymorphisms, monohydroxylated derivative (MHD) of oxcarbazepine (OXC) plasma concentrations, and OXC monotherapeutic efficacy were explored in 124 Chinese patients with epilepsy receiving OXC monotherapy.

METHOD

MHD is the major active metabolite of OXC, and its plasma concentration was measured using high-performance liquid chromatography when patients reached their maintenance dose of OXC. Genomic DNA was extracted from whole blood and SNP genotyping performed using PCR followed by dideoxy chain termination sequencing. We followed the patients for at least 1 year to evaluate the OXC monotherapy efficacy. Patients were divided into two groups according to their therapeutic outcome: group 1, seizure free; group 2, not seizure free. The data were analyzed using T test, one-way analysis of variance (ANOVA), Kruskal-Wallis test, chi-square test, Fisher's exact test, correlation analysis, and multivariate regression analysis.

RESULT

T test analysis showed that MHD plasma concentrations were significantly different between the two groups (p = 0.002). One-way ANOVA followed by Bonferroni post hoc testing of four candidate SNPs revealed that carriers of the UGT1A9 variant allele I399 C > T (TT 13.28 ± 7.44 mg/L, TC 16.41 ± 6.53 mg/L) had significantly lower MHD plasma concentrations and poorer seizure control than noncarriers (CC 22.24 ± 8.49 mg/L, p < 0.05).

CONCLUSION

In our study, we have demonstrated the effects of UGT1A9 genetic polymorphisms on MHD plasma concentrations and OXC therapeutic efficacy. Through MHD monitoring, we can predict OXC therapeutic efficacy, which may be useful for the personalization of OXC therapy in epileptic patients.

WITHDRAWN: Oxcarbazepine add-on for drug-resistant partial epilepsy

BACKGROUND

Most people with epilepsy have a good prognosis and their seizures can be well controlled with the use of a single antiepileptic drug, but up to 30% develop refractory epilepsy, especially those with partial seizures. In this review we summarize the current evidence regarding oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy.

OBJECTIVES

To evaluate the effects of oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy.

SEARCH METHODS

We searched the Cochrane Epilepsy Group's Specialized Register (28 March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2006), MEDLINE (1966 to March 2006). No language restrictions were imposed. We checked the reference lists of retrieved studies for additional reports of relevant studies. We also contacted Novartis (manufacturers of oxcarbazepine) and experts in the field.

SELECTION CRITERIA

Randomized, placebo-controlled, double-blinded, add-on trials of oxcarbazepine in patients with drug-resistant partial epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and extracted the relevant data. The following outcomes were assessed : (a) 50% or greater reduction in seizure frequency; (b) treatment withdrawal (any reason); (c) side effects. Primary analyses were intention-to-treat. Summary odds ratios were estimated for each outcome.

MAIN RESULTS

Two trials were included representing 961 randomized patients.Overall Odds Ratio (OR) (95% Confidence Interval (CIs)) for 50% or greater reduction in seizure frequency compared to placebo 2.96 (2.20, 4.00).Treatment withdrawal OR (95% CIs) compared to placebo 2.17 (1.59, 2.97).Side effects: OR (99% CIs) compared to placebo, ataxia 2.93 (1.72, 4.99); dizziness 3.05 (1.99, 4.67); fatigue 1.80 (1.02, 3.19); nausea 2.88 (1.77, 4.69); somnolence 2.55 (1.84, 3.55); diplopia 4.32 (2.65, 7.04), were significantly associated with oxcarbazepine.

AUTHORS' CONCLUSIONS

Oxcarbazepine has efficacy as an add-on treatment in patients with drug-resistant partial epilepsy, both in adults and children. However, trials reviewed were of relatively short duration, and provide no evidence about the long-term effects of oxcarbazepine. Results cannot be extrapolated to monotherapy or to patients with other epilepsy types.

Transformation of atenolol, metoprolol, and carbamazepine in soils: The identification, quantification, and stability of the transformation products and further implications for the environment

Pharmaceuticals are a large group of substances that have been recognized as environmental contaminants in recent years. Research on the pharmaceutical fate in soils is currently limited or missing. In this study, three pharmaceuticals (atenolol (ATE), carbamazepine (CAR), and metoprolol (MET)) were introduced to soils and exposed for 61 day under aerobic conditions. Thirteen different soils were used in the study to increase the understanding of pharmaceutical behaviour in the soil matrix. Ten metabolites were detected and tentatively identified. Some of them, such as atenolol acid (AAC), carbamazepine 10,11-epoxide (EPC), 10,11-dihydrocarbamazepine (DHC), trans-10,11-Dihydro-10,11-dihydroxy carbamazepine (RTC), and metoprolol acid (MAC), were consequently confirmed using commercial reference standards. It was concluded that the aerobic conditions of the experiment determined the pharmaceutical degradation pathway of studied compounds in the soils. The different amounts/rates and degradation of the transformation products can be attributed to differences in the soil properties. ATE degraded relatively quickly compared with CAR, whereas MET degradation in the soils was unclear. The persistence of CAR and its metabolites, in combination with low CAR sorption, enable the transportation of CAR and its metabolites within soils and into the ground water. Thus, CAR may cause adverse effects on the environment and humans.

Antiepileptic Drugs

PURPOSE OF REVIEW

Treatment of epilepsy starts with antiepileptic drug (AED) monotherapy. Knowledge of the spectrum of efficacy, clinical pharmacology, and modes of use for individual AEDs is essential for optimal treatment for epilepsy. This article addresses AEDs individually, focusing on key pharmacokinetic characteristics, indications, and modes of use.

RECENT FINDINGS

Older-generation AEDs are effective but have tolerability and pharmacokinetic disadvantages. Several newer-generation AEDs have undergone comparative trials demonstrating efficacy equal to and tolerability at least equal to or better than older AEDs as first-line therapy. The list includes lamotrigine, oxcarbazepine, levetiracetam, topiramate, and, more recently, zonisamide. Pregabalin was found to be less effective than lamotrigine. Lacosamide, pregabalin, and eslicarbazepine have undergone successful trials of conversion to monotherapy. Other newer-generation AEDs with a variety of mechanisms of action are suitable for adjunctive therapy. Rational AED combinations should avoid AEDs with unfavorable pharmacokinetic interactions or pharmacodynamic interactions related to mechanism of action.

SUMMARY

Knowledge of AED pharmacokinetics, efficacy, and tolerability profiles facilitates the choice of appropriate AED therapy for patients with epilepsy.

[A proposal for a model to replace carbamazepine or oxcarbazepine by eslicarbazepine acetate in clinical practice]

INTRODUCTION

For many years carbamazepine (CBZ) has been the reference drug for the treatment of partial epileptic seizures. However, the problems related with its pharmacokinetics and safety have led to the development of other derivatives, such as oxcarbazepine (OXC) and, more recently, eslicarbazepine acetate (ESL), which do not display these drawbacks.

DEVELOPMENT

In clinical practice, the possibility of replacing CBZ or OCX by ESL is a relatively frequent occurrence, the aim being to maintain the efficacy of its predecessors and benefit from the advantages in terms of the pharmacokinetics and safety of this latter derivative. To achieve this, it is essential to have an approximate dose equivalence and exchange protocol. This review offers a practical reasoned model for carrying out the change.

CONCLUSIONS

The shift from OXC to ESL can be completed from one day to the next with a dose equivalence of 1-1.5 to 1. Replacement of CBZ by ESL must be more progressive, and the dose equivalence is established as 1-1.3 to 1.

Comparative persistence of antiepileptic drugs in patients with epilepsy: A STROBE-compliant retrospective cohort study

We compared persistence of antiepileptic drugs (AEDs) including carbamazepine, oxcarbazepine, gabapentin, lamotrigine, topiramate, valproic acid, and phenytoin in an Asian population with epilepsy.A retrospective cohort study was conducted by analyzing Taiwan's National Health Insurance Research Database (NHIRD). Adult epilepsy patients newly prescribed with AEDs between 2005 and 2009 were included. The primary outcome was persistence, defined as the treatment duration from the date of AED initiation to the date of AED discontinuation, switching, hospitalization due to seizure or disenrollment from databases, whichever came first. Cox proportional hazard models were used to estimate the risk of non-persistence with AEDs.Among the 13,061 new users of AED monotherapy (mean age: 58 years; 60% men), the persistence ranged from 218.8 (gabapentin) to 275.9 (oxcarbazepine) days in the first treatment year. The risks of non-persistence in patients receiving oxcarbazepine (adjusted hazard ratio [HR], 0.78; 95% CI, 0.74-0.83), valproic acid (0.88; 0.85-0.92), lamotrigine (0.72; 0.65-0.81), and topiramate (0.90; 0.82-0.98) were significantly lower than in the carbamazepine group. Compared with carbamazepine users, the non-persistence risk was higher in phenytoin users (1.10; 1.06-1.13), while gabapentin users (1.03; 0.98-1.09) had similar risk. For risk of hospitalization due to seizure and in comparison with carbamazepine users, oxcarbazepine (0.66; 0.58-0.74) and lamotrigine (0.46; 0.35-0.62) users had lower risk, while phenytoin (1.35; 1.26-1.44) users had higher risk. The results remained consistent throughout series of sensitivity and stratification analyses.The persistence varied among AEDs and was better for oxcarbazepine, valproic acid, lamotrigine, and topiramate, but worse for phenytoin when compared with carbamazepine.

Effect of Carbamazepine 10, 11-Epoxide on Serum Carbamazepine Measurement Using a New CMIA Assay: Comparison of Values Obtained by Using PETINIA, CEDIA and Liquid Chromatography Combined with Tandem Mass Spectrometry

BACKGROUND

Carbamazepine is a classical anticonvulsant that requires therapeutic drug monitoring. We evaluated the effect of carbamazepine 10, 11 epoxide on a new chemiluminescent immunoassay (CMIA) for application on the Architect i1000SR analyzer.

MATERIALS AND METHODS

Carbamazepine concentrations were measured in 40 specimens collected from patients taking carbamazepine using a PETINIA assay (Vista 1500 analyzer), a CEDIA assay (Cobas c501 analyzer) and the new CMIA assay (Architect i1000 analyzer). In addition, carbamazepine and carbamazepine 10, 11-epoxide concentrations were determined using a reference liquid chromatography combined with a tandem mass spectrometry (LC/MS/MS) reference method in another 15 specimens. These specimens were further analyzed using the PETINIA, CEDIA and CMIA assays.

RESULTS AND DISCUSSION

A good correlation (regression equation: y = 0.9605x+0.2788, n=40, r=0.98) between values obtained by using the CEDIA assay (x-axis) and the CMIA assay (y-axis) was observed but the PETINIA assay showed significant bias compared to the CMIA assay (regression equation: y=0.8191x+0.3069, n=40, r=0.97). The bias was due to high cross-reactivity of epoxide with the PETINIA assay as revealed by comparing carbamazepine values obtained by LC-MS/MS with these three assays.

CONCLUSIONS

The new CMIA assay is suitable for therapeutic drug monitoring of carbamazepine because values correlated well with the CEDIA assay values (n=40) as well as LC-MS/MS reference method values in 15 specimens.

POCIS passive samplers as a monitoring tool for pharmaceutical residues and their transformation products in marine environment

In the last years, several scientific studies have shown that carbamazepine (CBZ) is one of the most frequently detected pharmaceutical in aquatic environment. However, little data is available on its detection and its transformation products (TPs) in marine water. The use of polar organic chemical integrative sampling (POCIS) passive samplers as a semi-quantitative and qualitative tool for screening of pharmaceuticals and TPs in seawater has been studied. Furthermore, the uptake rates of the target compounds were also determined under laboratory experiments to characterize the levels accumulated in devices. The results confirmed the presence of residues of anticonvulsant CBZ as well as some of its main metabolites, over a 1-year monitoring campaign carried out in French coast on the Mediterranean Sea. The work reports for the first time the presence of two TPs (10,11-dihydro-10,11-trans-dihydroxycarbamazepine (TRANS) and 10-hydroxy-10,11-dihydrocarbamazepine (10OH)) in marine water. The results contribute in assessing the environmental and human health risk of pharmaceuticals on coastal areas.

Degradation of oxcarbazepine by UV-activated persulfate oxidation: kinetics, mechanisms, and pathways

The degradation kinetics and mechanism of the antiepileptic drug oxcarbazepine (OXC) by UV-activated persulfate oxidation were investigated in this study. Results showed that UV/persulfate (UV/PS) process appeared to be more effective in degrading OXC than UV or PS alone. The OXC degradation exhibited a pseudo-first order kinetics pattern and the degradation rate constants (k obs) were affected by initial OXC concentration, PS dosage, initial pH, and humic acid concentration to different degrees. It was found that low initial OXC concentration, high persulfate dosage, and initial pH enhanced the OXC degradation. Additionally, the presence of humic acid in the solution could greatly inhibit the degradation of OXC. Moreover, hydroxyl radical (OH•) and sulfate radical (SO4 (-)••) were identified to be responsible for OXC degradation and SO4 (-)• made the predominant contribution in this study. Finally, major intermediate products were identified and a preliminary degradation pathway was proposed. Results demonstrated that UV/PS system is a potential technology to control the water pollution caused by emerging contaminants such as OXC.

Phytoremediation of carbamazepine and its metabolite 10,11-epoxycarbamazepine by C3 and C4 plants

The anticonvulsant drug carbamazepine is considered as an indicator of sewage water pollution: however, its uptake by plants and effect on metabolism have not been sufficiently documented, let alone its metabolite (10,11-epoxycarbamazepine). In a model system of sterile, hydroponically cultivated Zea mays (as C4 plant) and Helianthus annuus (as C3 plant), the uptake and effect of carbamazepine and 10,11-epoxycarbamazepine were studied in comparison with those of acetaminophen and ibuprofen. Ibuprofen and acetaminophen were effectively extracted from drug-supplemented media by both plants, while the uptake of more hydrophobic carbamazepine was much lower. On the other hand, the carbamazepine metabolite, 10,11-epoxycarbamazepine, was, unlike sunflower, willingly taken up by maize plants (after 96 h 88 % of the initial concentration) and effectively stored in maize tissues. In addition, the effect of the studied pharmaceuticals on the plant metabolism (enzymes of Hatch-Slack cycle, peroxidases) was followed. The activity of bound peroxidases, which could cause xylem vessel lignification and reduction of xenobiotic uptake, was at the level of control plants in maize leaves contrary to sunflower. Therefore, our results indicate that maize has the potential to remove 10,11-epoxycarbamazepine from contaminated soils.

Determination of the psychoactive drugs carbamazepine and diazepam in hospital effluent and identification of their metabolites

This study addresses the occurrence of carbamazepine and diazepam and their metabolites in the wastewater of the University Hospital (HUSM) of the Federal University of Santa Maria, RS-Brazil. Samples were collected from three sampling points of the sewage treatment system: point A ('emergency effluent'), point B ('general effluent') and point C ('water course-receptor'). Eight metabolites were identified: carbamazepine-10-11-epoxide, 10-dihydro-carbamazepine, 2-OH-carbamazepine, iminoquinone, acridone, nordiazepam, oxazepam and temazepam. The mean concentrations in the emergency, general effluent and water course-receptor were as follows: 433.0 ± 4.7, 349.0 ± 5.0 and 485.0 ± 5.6 ng L(-1), for carbamazepine and 550.0 ± 4.3, 441.0 ± 7.9 and 586.6 ± 9.3 ng L(-1), for diazepam, respectively. Liquid chromatography with electrospray ionization tandem mass spectrometry (LC-QqLIT-MS) proved to be a method fit-to-purpose. The determination of carbamazepine and diazepam, and the identification of active metabolites showing environmental persistence (carbamazepine-10-11-epoxide, nordiazepam and oxazepam) revealed the need for a more effective treatment of the HUSM effluent. As far as we know, no similar study has been carried out on the wastewater of Brazilian hospitals.

In vivo exposure of marine mussels to carbamazepine and 10-hydroxy-10,11-dihydro-carbamazepine: Bioconcentration and metabolization

Aquatic organisms are exposed to pharmaceuticals present in natural waters, but few data are available on the accumulation of these substances in such organisms. The present study evaluated the in vivo bioconcentration of two anticonvulsants--carbamazepine (CBZ) and 10-hydroxy-10,11-dihydro-carbamazepine (10 OH)--in marine mussels (Mytilus galloprovincialis) exposed to nominal 10 μg L(-1) concentrations for one week. The bioconcentration factors (BCFs) were 3.9 and 4.5 L kg(-1) dry weight (dw) for CBZ and 10 OH, respectively. CBZ accumulation reached an average tissue concentration of 29.3 ± 4.8 ng g(-1) dw, and 10 OH accumulated up to 40.9 ± 4.6 ng g(-1) dw in tissues within one week, showing first-order kinetics. BCF obtained with linear QSAR models correctly estimated the CBZ bioconcentration and overestimated the 10 OH bioconcentration to some extent. The detection of two metabolites (carbamazepine-10,11-epoxide and acridine) among the five sought suggested an active metabolism for CBZ. In contrast, none of the 10 OH metabolites were detected in mussels exposed to 10 OH. CBZ showed higher accumulation in the digestive gland, where some relevant metabolites were detected, than in other studied tissues. The implication of those findings on field biomonitoring is discussed.

Encephalopathy with status epilepticus during sleep (ESES) induced by oxcarbazepine in idiopathic focal epilepsy in childhood

Encephalopathy with status epilepticus during sleep (ESES) is an age-related disorder characterized by neuropsychological regression, epilepsy and a typical EEG pattern of continuous epileptiform activity (> 85%) during NREM sleep. Cases of worsening or induction of ESES with phenytoin, carbamazepine and phenobarbital have been reported. We describe a child with benign epilepsy with centrotemporal spikes (BECTS) in whom treatment with oxcarbazepine (OXC) induced ESES. The patient was studied through repeated clinical-neuropsychological evaluations and 24-hour EEG recordings. He was treated with OXC two months after epilepsy onset. One month after starting OXC, he developed an abrupt and severe cognitive deterioration. A 24-hour EEG and neuropsychological tests showed an electroclinical picture compatible with ESES. Withdrawal of OXC and introduction of other drugs were followed by a prompt improvement. Five months after ESES onset, a 24-hour EEG was normal. Our report indicates that OXC can induce ESES in BECTS.

Why Small Differences Matter: Elucidation of the Mechanisms Underlying the Transformation of 2OH- and 3OH-Carbamazepine in Contact with Sand Filter Material

Carbamazepine (CBZ) is a worldwide used antiepileptic drug, which is metabolized to a large extent in the human body to several metabolites, including 10,11-dihydroxy-10,11-dihydrocarbamazepine (DiOHCBZ), 2-hydroxycarbamazepine (2OHCBZ), and 3-hydroxycarbamazepine (3OHCBZ). 2OHCBZ and 3OHCBZ were previously detected in raw and treated wastewater revealing their widespread emission into the aquatic environment, eventually leading to the contamination of drinking water resources. Sand filtration is frequently applied in drinking water treatment for the removal of inorganic species and suspended particles but has been shown to be capable of removing trace organic contaminants. This study focuses on the elucidation of the (bio)transformation mechanisms of 2OHCBZ and 3OHCBZ in contact with material taken from a rapid sand filter of a German waterworks. Despite their similar structure, which differs only in the position of the phenolic OH moiety, both compounds underwent distinct transformation reactions leading to the formation of a variety of transformation products (TPs). The main biochemical reactions thereby included enzymatic transformation of 2OHCBZ resulting in the formation of a reactive iminoquinone intermediate (2OHCBZ) and nitration via peroxynitrite (2OHCBZ and 3OHCBZ) as well as formation of radicals leading to dimerization (3OHCBZ). Further transformation reactions included hydroxylation, ring cleavage, loss of carbamoyl group, and decarboxylation, as well as O-methylation.

Puddles - A trigger for heterogeneous chemical influx into the unsaturated zone

Spatial heterogeneity in the chemical concentration of interstitial water in the vadose zone was previously observed under apparently homogeneous surface conditions on two leveled fields sprinkler irrigated with treated sewage effluents on the phreatic Coastal Plain aquifer of Israel. This phenomenon greatly hampers the monitoring of groundwater quality. In this study we report on the presence of puddles of different size and shape that were sporadically observed in these fields. Temporal variability noted in the concentration of treated sewage effluents components in the puddles were considered to be related to evapotranspiration and degradation. For example: increases in the electrical conductivity (up to 1.32 mS/cm), and in the concentrations of chloride (up to 521 mg/L), dissolved organic carbon (up to 28.4 mg/L), and carbamazepine (up to 780 ng/L) and decreases in the concentrations of nitrate (up to 20.1mg/L) and caffeine (3,396 ng/L). Variable trends in concentration were observed for sulfamethoxazole, venlafaxine, 10-hydroxy-10,11-dihydrocarbamazepine and o-desmethylvenlafaxine. The presence of puddles was not necessarily related to areas with high irrigation water input. It is postulated that the continuous chemical variability in the puddles, whose location and size are also variable, determine a heterogeneous influx of solutes into the soil and subsequently into the vadose zone.

Management of adverse effects of mood stabilizers

Mood stabilizers such as lithium and anticonvulsants are still standard-of-care for the acute and long-term treatment of bipolar disorder (BD). This systematic review aimed to assess the prevalence of their adverse effects (AEs) and to provide recommendations on their clinical management. We performed a systematic research for studies reporting the prevalence of AEs with lithium, valproate, lamotrigine, and carbamazepine/oxcarbazepine. Management recommendations were then developed. Mood stabilizers have different tolerability profiles and are eventually associated to cognitive, dermatological, endocrine, gastrointestinal, immunological, metabolic, nephrogenic, neurologic, sexual, and teratogenic AEs. Most of those can be transient or dose-related and can be managed by optimizing drug doses to the lowest effective dose. Some rare AEs can be serious and potentially lethal, and require abrupt discontinuation of medication. Integrated medical attention is warranted for complex somatic AEs. Functional remediation and psychoeducation may help to promote awareness on BD and better medication management.

Comparative Long-Term Effectiveness of a Monotherapy with Five Antiepileptic Drugs for Focal Epilepsy in Adult Patients: A Prospective Cohort Study

Objective

To evaluate and compare long-term effectiveness of five antiepileptic drugs (AEDs) for monotherapy of adult patients with focal epilepsy in routine clinical practice.

Methods

Adult patients with focal epilepsy, who were prescribed with carbamazepine (CBZ), valproate (VPA), lamotrigine (LTG), topiramate (TPM), or oxcarbazepine (OXC) as monotherapy, during the period from January 2004 to June 2012 registered in Wenzhou Epilepsy Follow Up Registry Database (WEFURD), were included in the study. Prospective long-term follow-up was conducted until June 2013. The endpoints were time to treatment failure, time to seizure remission, and time to first seizure.

Results

This study included 654 patients: CBZ (n=125), VPA (n=151), LTG (n=135), TPM (n=76), and OXC (n=167). The retention rates of CBZ, VPA, LTG, TPM, and OXC at the third year were 36.1%, 32.4%, 57.6%, 37.9%, and 41.8%, respectively. For time to treatment failure, LTG was significantly better than CBZ and VPA (LTG vs. CBZ, hazard ratio, [HR] 0.80 [95% confidence interval: 0.67-0.96], LTG vs. VPA, 0.53 [0.37-0.74]); TPM was worse than LTG (TPM vs. LTG, 1.77 [1.15-2.74]), and OXC was better than VPA (0.86 [0.78-0.96]). After initial target doses, the seizure remission rates of CBZ, VPA, LTG, TPM, and OXC were 63.0%, 77.0%, 83.6%, 67.9%, and 75.3%, respectively. LTG was significantly better than CBZ (1.44 [1.15-1.82]) and OXC (LTG vs. OXC, 0.76 [0.63-0.93]); OXC was less effective than LTG in preventing the first seizure (1.20 [1.02-1.40]).

Conclusion

LTG was the best, OXC was better than VPA only, while VPA was the worst. The others were equivalent for comparisons between five AEDs regarding the long-term treatment outcomes of monotherapy for adult patients with focal epilepsy in a clinical practice. For selecting AEDs for these patients among the first-line drugs, LTG is an appropriate first choice; others are reservation in the first-line but VPA is not.

The establish of the HPLC method to examine the plasma concentration of lamotrigine and oxcarbazepine

To establish the HPLC method to examine plasma concentration of lamotrigine and oxcarbazepine. This study set chlorzoxazone as the internal standard, chromatographic column was Column C18 (200×4.6mm, 5um) of DIKMA company, the mobile phase was methanol, water and trifluoroacetic acid, with rate of 40: 60: 0.0005, at a flow rate of 1 mllmin(-1), the detected wavelength was 240 nm. The plasma concentrations of lamotrigine was 0.5-50ug•mL(-1), the standard curve was excellent for Y=0.5511C-0.5669, r=0.9940, average recovery was 91.40%; The plasma concentrations of oxcarbazepine was 0.5-50ugmL-1, the standard curve was good for Y=0.4026C-0.5895, r=0.9925, and the average recovery was 89.59%; The three plasma concentrations of lamotrigine were respectively 25μg•mL(-1), 10 μg•mL(-1) and 2μg•mL(-1) and its five parallel sample for injection RSD were respectively 4.01%, 6.15% and 4.64%; The three plasma concentration of oxcarbazepine were 25μg•mL(-1)-1(-1), 10μg•mL(-1)-1(-1) and 2μg•mL(-1)-1(-1), and its five parallel sample for injection RSD were respectively 3.05%, 4.27% and 9.01%. This method was easy to operate, high recovery and high precision, and was applicable to the clinical detection for plasma concentration of lamotrigine and oxcarbazepine.

[Adverse effects of oxcarbazepine]

Oxcarbazepine is a new antiepileptic drug. The results of clinical trials suggest that oxcarbazepine is well tolerated and has less drug interactions. It is being used more and more widely in clinical practice, but its adverse effects should not be ignored. The most common adverse effects of oxcarbazepine are usually related to the central nervous system and digestive system, including fatigue, drowsiness, diplopia, dizziness, nausea and vomit. The common skin adverse reaction is rash. Long-term use of oxcarbazepine may also cause hyponatremia. This article reviews the literature from China and overseas about the adverse effets of oxcarbazepine over the last 10 years in order to find information about rational clinical use of oxcarbazepine.