The star systems: overview and use in determining antiepileptic drug choice

Current Principles in the Management of Drug-Resistant Epilepsy

Drug-resistant epilepsy is associated with poor health outcomes and increased economic burden. In the last three decades, various new antiseizure medications have been developed, but the proportion of people with drug-resistant epilepsy remains relatively unchanged. Developing strategies to address drug-resistant epilepsy is essential. Here, we define drug-resistant epilepsy and emphasize its relationship to the conceptualization of epilepsy as a symptom complex, delineate clinical risk factors, and characterize mechanisms based on current knowledge. We address the importance of ruling out pseudoresistance and consider the impact of nonadherence on determining whether an individual has drug-resistant epilepsy. We then review the principles of epilepsy drug therapy and briefly touch upon newly approved and experimental antiseizure medications.

Ionic and synaptic mechanisms of seizure generation and epileptogenesis

The biophysical mechanisms underlying epileptogenesis and the generation of seizures remain to be better understood. Among many factors triggering epileptogenesis are traumatic brain injury breaking normal synaptic homeostasis and genetic mutations disrupting ionic concentration homeostasis. Impairments in these mechanisms, as seen in various brain diseases, may push the brain network to a pathological state characterized by increased susceptibility to unprovoked seizures. Here, we review recent computational studies exploring the roles of ionic concentration dynamics in the generation, maintenance, and termination of seizures. We further discuss how ionic and synaptic homeostatic mechanisms may give rise to conditions which prime brain networks to exhibit recurrent spontaneous seizures and epilepsy.

Patterns of antiepileptic drug use in patients with potential refractory epilepsy in Texas Medicaid

OBJECTIVES

Antiepileptic drug (AED) monotherapy is usually effective in 60% of the patients with epilepsy while the remaining patients have refractory epilepsy. This study compared treatment patterns (adherence, persistence, addition, and switching) associated with refractory and nonrefractory epilepsy.

METHODS

Texas Medicaid claims from 09/01/07-12/31/13 were analyzed, and patients eligible for the study 1) were between 18 and 62 years of age, 2) had a prescription claim for an AED during the identification period (03/01/08-12/31/11) with no prior baseline AED use (6-month), and 3) had evidence of epilepsy diagnosis within 6 months of AED use. Based on AED use in the identification period, patients were categorized into "refractory" (≥3AEDs) and "nonrefractory" (<3AEDs) cohorts. The index date was the date of the first AED claim. Patients in both cohorts were matched 1:1 using propensity scoring and compared for adherence (proportion of days covered (PDC) ≥80% vs. <80%), persistence, addition (yes/no), and switching (yes/no) using multivariate conditional regression models. Conditional logistic regression and Cox proportional hazard models were used to address the study objectives.

RESULTS

Of the 10,599 eligible patients, 2798 (26.5%) patients in the refractory cohort were matched to patients in the nonrefractory cohort. Patients in the refractory cohort had significantly higher (p < 0.005) mean (±Standard deviation (SD)) adherence (88.6% (±19.1%) vs. 77.0% ± (25.8%)) and persistence (328.0 (±87.3) days vs. 294.9 ± (113.4) days) as compared with patients in the nonrefractory cohort. Compared with patients with nonrefractory epilepsy, patients with refractory epilepsy were 3.6 times (odds ratio (OR) = 3.553; 95% confidence interval (CI) = 3.060-4.125; p < 0.0001) more likely to adhere to AEDs and had a 34.7% (hazard ratio (HR) = 0.653; 95% CI = 0.608-0.702; p < 0.0001) lower hazard rate of discontinuation of AEDs. Also, patients with refractory epilepsy were 3.7 times (OR = 3.723; 95% CI = 2.902-4.776; p < 0.0001) more likely to add an alternative AED and 3.6 times (OR = 3.591; 95% CI = 3.010-4.284; p < 0.0001) more likely to switch to an alternative AED.

CONCLUSION

Patients with refractory epilepsy were significantly more likely to adhere and persist to AED regimen and were significantly more likely to add and switch to an alternative AED than patients with nonrefractory epilepsy.

Methods for Incorporating Patient Preferences for Treatments of Depression in Community Mental Health Settings

We developed three methods (rating, ranking, and discrete choice) for identifying patients' preferred depression treatments based on their prioritization of specific treatment attributes (e.g., medication side effects, psychotherapy characteristics) at treatment intake. Community mental health patients with depressive symptoms participated in separate studies of predictive validity (N = 193) and short-term (1-week) stability (N = 40). Patients who received non-preferred initial treatments (based on the choice method) switched treatments significantly more often than those who received preferred initial treatments. Receiving a non-preferred treatment at any point (based on rating and choice methods) was a significant predictor of longer treatment duration. All three methods demonstrated good short-term stability.

Emerging drugs for partial-onset epilepsy: a review of brivaracetam

There are more than 12 new antiepileptic drugs approved in the last 2 decades. Even with these newer agents, seizure remission is still unachievable in around 30% of patients with partial-onset seizures (POS). Brivaracetam (BRV) is chemically related to levetiracetam (LEV) and possesses a strong binding affinity for the synaptic vesicle protein 2A tenfold above that of LEV, and other possible modes of antiepileptic actions. BRV is now under Phase III development for POS, but data from one Phase III trial also suggested its potential efficacy for primary generalized seizures. The purpose of this review is to provide updated information on the mechanisms of action of the available antiepileptic drugs, with a focus on BRV to assess its pharmacology, pharmacokinetics, clinical efficacy, safety, and tolerability in patients with uncontrolled POS. To date, six Phase IIb and III clinical trials have been performed to investigate the efficacy, safety, and tolerability of BRV as an adjunctive treatment for patients with POS. Generally, BRV was well tolerated and did not show significant difference in safety profile, compared to placebo. The efficacy outcomes of BRV, although not consistent across trials, did indicate that BRV was a promising add-on therapy for patients with POS. In conclusion, the many favorable attributes of BRV, like its high oral efficacy, good tolerability, dosing regimen, and minimal drug interaction, make it a promising antiepileptic therapy for patients with uncontrolled partial-onset epilepsy.

Antiepileptic drugs--a review

Epilepsy is a common neurological condition that affects approximately 1% of the general population. In addition, about 10% of the population experiences a seizure sometime during life. The treatment options for epilepsy have come a long way from the bromides to the current era in which we now have multiple treatment modalities, including medications, implantable devices, and surgery. Antiepileptic drugs (AEDs) are the mainstay for treatment of epilepsy with about 70% of children achieving good control with medications alone. The past decade has witnessed the emergence of multiple AEDs-with more than 24 AEDs to choose from presently. The newer drugs provide us with novel mechanisms of action and improved safety profile. This expanded choice of AEDs has made it possible to offer tailored-treatment plans based on unique patient profiles. However, such an ever-increasing choice of medications also poses a challenge for the treating physician as far as choosing the initial drug is concerned-especially because there is limited data comparing the efficacy of one drug to the other. An additional humbling fact remains that, despite an increase in the choice of medications, we are still only able to treat the symptoms of seizures without making any significant progress in reversing or stopping the underlying mechanism of epileptogenesis or in offering neuroprotection from epileptogenesis. Therefore, it is not surprising that, despite the wide array of AED choices, the prevalence of drug-resistant epilepsy has not improved. This article aims at giving a short overview of currently available AEDs.

Interactions between levetiracetam and cardiovascular drugs against electroconvulsions in mice

BACKGROUND

Hypertension and heart failure belong to common comorbid conditions with epilepsy so drug interactions between antiepileptics and cardiovascular drugs are possible in clinical practice. The aim of this study was to evaluate the effects of angiotensin AT1 receptor antagonists (losartan potassium and candesartan cilexetil), angiotensin-converting enzyme (ACE) inhibitors (captopril and perindopril arginine) and diuretics (hydrochlorothiazide and ethacrynic acid) on the anticonvulsant activity of levetiracetam (LEV) in mice.

METHODS

The protective action of LEV was examined in the maximal electroshock seizure threshold test. Drugs were administered intraperitoneally (ip). Additionally, combinations of cardiovascular drugs with LEV were tested for adverse effects in the passive avoidance task and the chimney test.

RESULTS

Losartan potassium (50mg/kg), candesartan cilexetil (8mg/kg), captopril (50mg/kg), hydrochlorothiazide (100mg/kg) and ethacrynic acid (100mg/kg) did not affect the anticonvulsant activity of LEV. Perindopril arginine (10mg/kg) raised the convulsive threshold for LEV administered at doses of 100, 300 and 500mg/kg. This interaction could be pharmacodynamic in nature because the brain concentration of LEV remained unchanged by perindopril. The adverse effects of the combined treatment with LEV and cardiovascular drugs were not observed in the passive avoidance task or the chimney test.

CONCLUSIONS

Although experimental data can be hardly extrapolated to clinical practice, it is suggested that perindopril arginine may positively influence the anticonvulsant action of LEV in epileptic patients. The use of losartan potassium, candesartan cilexetil, captopril, hydrochlorothiazide or ethacrynic acid in patients treated with LEV seems neutral regarding its anticonvulsant activity.

Treatment of epilepsy in China: Formal or informal

Antiepileptic drugs are the preferred treatment approach for epileptic patients. However, informal treatment is important for intractable epilepsy. In this study, 500 epileptic patients were recruited from the General Hospital of Beijing Military Area Command of Chinese PLA during the period of October 2009 to January 2012. These involved patients that had been medically treated for at least 1 year. Information on the initial treatment and changes to treatment regimens for each patient was collected through questionnaires. The survey results showed that 52.3% of the epileptic patients searched for treatment after the first seizure, and the mean numbers of seizures was 12.8; 59.8% of the epileptic patients were diagnosed at the first visit, and the mean onset time was 17 months after the first seizure. After diagnosis, patients were treated for an average of 20 days, and the median time was 1 day. Formal anti-epileptic drugs were selected as the first treatment regimen by 67.8% of patients, and 77.5% of these drugs were monotherapies. The mean and median numbers of seizure were respectively 36.9 and 3.0 times before the first regimen was changed. The regimen was changed within the first 6 months by 46.6% of patients, and after the first and second years of treatment, the proportions increased to 54.0% and 71.8%, respectively. In total, 78.5% of the regimens were changed to informal treatments. The informal treatment of epilepsy in China is common, being initiated by either patients or physicians. Enhancing epileptic treatment services in hospital, improving physicians’ professional quality, and strengthening health propaganda may promote the normalization of drug treatment of epilepsy in China.

Anticonvulsant and related neuropharmacological effects of the whole plant extract of Synedrella nodiflora (L.) Gaertn (Asteraceae)

Purpose:

The plant Synedrella nodiflora (L) Gaertn is traditionally used by some Ghanaian communities to treat epilepsy. To determine if this use has merit, we studied the anticonvulsant and other neuropharmacological effects of a hydro-ethanolic extract of the whole plant using murine models.

Materials and Methods:

The anticonvulsant effect of the extract (10–1000 mg/kg) was tested on the pentylenetetrazole-, picrotoxin-, and pilocarpine-induced seizure models and PTZ-kindling in mice/rats. The effect of the extract was also tested on motor coordination using the rota-rod.

Results:

The results obtained revealed that the extract possesses anticonvulsant effects in all the experimental models of seizures tested as it significantly reduced the latencies to myoclonic jerks and seizures as well as seizure duration and the percentage severity. The extract was also found to cause motor incoordination at the higher dose of 1000 mg/kg.

Conclusions:

In summary, the hydro-ethanolic extract of the whole plant of S. nodiflora possesses anticonvulsant effects, possibly through an interaction with GABAergic transmission and antioxidant mechanisms and muscle relaxant effects. These findings thus provide scientific evidence in support of the traditional use of the plant in the management of epilepsy.

Patients' preferences for treatment outcomes of add-on antiepileptic drugs: a conjoint analysis

To understand the relative importance of the outcomes of add-on antiepileptic drugs (AEDs) and the willingness of patients with epilepsy to accept therapeutic trade-offs between seizure control and tolerability, we administered a Web-enabled, choice-format conjoint survey to patients with a self-reported physician diagnosis of epilepsy and symptoms of partial seizures. Patients answered nine choice questions to evaluate treatment outcomes of two different hypothetical add-on AEDs. Patients were first asked to choose the better of the two medicines and then asked a follow-up question about whether or not they would add the selected AED to their current treatment regimen. Our study demonstrated that patients with epilepsy consider seizure reduction to be the top priority when ranking it against the reduction or elimination of side effects. This study aids in better understanding of patients' AED treatment preferences and may aid in management of epilepsy.

Identifying the biologic closest to the ideal to treat chronic plaque psoriasis in different clinical scenarios: using a pilot multi-attribute decision model as a decision-support aid

OBJECTIVE

Multi-attribute decision-making (MADM) models evaluate competing solutions for complex problems to identify the closest fit to the ideal solution. MADM models may assist dermatologists when selecting between biologics for plaque psoriasis. Here, is described the development of a pilot model to identify the preferred biologic from the dermatologist's perspective.

RESEARCH DESIGN AND METHODS

A group of European dermatologists were surveyed to identify treatment attributes they consider when prescribing a biologic. The relative importance of each was determined by allocation of 100 importance points in the context of seven case vignettes, reflecting the breadth of disease encountered in dermatological practice. Biologic performance was rated anonymously on a scale of 1-10, scores entered into a MADM matrix, and TOPSIS (Technique for Ordered Preference by Similarity to the Ideal Solution) analysis applied to identify the biologic closest to the hypothetical ideal.

RESULTS

Long-term efficacy and safety were the most important attributes considered by dermatologists when selecting a biologic. For one case vignette (chronic stable psoriasis), TOPSIS scores showed that etanercept was closest to the ideal for 63% of respondents, with adalimumab closest to the ideal for 32% of respondents. Differences among the biologics were highly significant (p < 0.0001). For severe unstable psoriasis, infliximab and adalimumab were preferred.

LIMITATION

This study was conducted with a group of dermatologists attending a Wyeth-sponsored advisory board meeting.

CONCLUSIONS

Based on responses from this expert group, etanercept was the preferred choice for stable chronic plaque psoriasis for the majority, with infliximab preferred for more severe disease. However, there are several limitations to this pilot model, most notably the non-random selection of the expert group. Further development of the model encompassing a random survey of dermatologists and inclusion of other treatment alternatives and the latest clinical data, will add to the clinical utility of the tool.

Intractable epilepsy: management and therapeutic alternatives

More than half of patients with newly diagnosed epilepsy achieve complete seizure control without major side-effects. Patients who continue to have seizures after initial medical therapy should have an early and detailed assessment to confirm the diagnosis, to determine the underlying cause and epilepsy syndrome, and to choose an adequate treatment strategy. The risks and potential benefits of surgical procedures or experimental therapy have to be weighed against the chance of improvement and the potential side-effects of additional medical therapy. Surgery for temporal lobe epilepsy, the most common cause of focal epilepsy, can control seizures and improve quality of life in appropriately selected patients. However, around 20-30% of patients do not respond to medical or surgical treatment. The management of chronic intractable epilepsy requires comprehensive care to address the adverse events of medical treatment, quality of life issues, and comorbid disorders. Much research focuses on the experimental treatment options that offer hope of seizure reduction or cure.

Comparative retention rates and long-term tolerability of new antiepileptic drugs

OBJECTIVE

Retention rates of five new anti-epileptic medications (AEDs) were compared in order to evaluate their long-term tolerability and efficacy.

METHOD

We acquired the retention data on levetiracetam (LEV), lamotrigine (LTG), oxcarbazepine (OXC), topiramate (TPM), and zonisamide (ZNS) from the electronic database. The data included patient's age, gender, seizure type, current and previous medications, dosage, main reasons for discontinuation, and duration of therapy. The retention rates of these AEDs were evaluated at 4, 12, 24, 52, and 104 weeks.

RESULTS

A total of 828 new AED exposures were obtained (LEV=196, LTG=251, OXC=97, TPM=156, ZNS=128) from patients with partial or generalized epilepsy. At 2 years, retention rate was highest with LTG (74.1%), followed by ZNS (60.2%), OXC (58.8%), LEV (53.6%), and TPM (44.2%). When these AEDs were discontinued, it was mainly due to inefficacy (29.5%) and sedating side-effects (20.5%), and commonly within 6 months into therapy. Several important AED specific side-effects leading to discontinuation were identified, including behavioral or irritability from LEV, rash from LTG and OXC, nausea from OXC and ZNS, hyponatremia from OXC, and kidney stones from TPM and ZNS.

CONCLUSION

Comparing retention rates of new AEDs can provide useful insight into their tolerability and efficacy. This study showed highest retention rate with LTG, which was significantly different from ZNS (p=0.0025), LEV (p<0.0001), OXC (p=0.0024), and TPM (p<0.0001). Beside ineffectiveness, other leading causes of discontinuation were adverse behavioral effects with LEV, rash with LTG and OXC, and sedation for TPM and ZNS.

Thirty years of clinical experience with carbamazepine in the treatment of bipolar illness: principles and practice

Carbamazepine began to be studied in a systematic fashion in the 1970s and became more widely used in the treatment of bipolar disorder in the 1980s. Interest in carbamazepine has been renewed by (i) the recent US FDA approval of a long-acting preparation for the treatment of acute mania; (ii) studies suggesting some efficacy in bipolar depression; and (iii) evidence of prophylactic efficacy in some difficult-to-treat subtypes of bipolar illness. A series of double-blind controlled studies of the drug were conducted at the US National Institute of Mental Health from the mid-1970s to the mid-1990s. This review summarises our experience in the context of the current literature on the clinical efficacy, adverse effects and pharmacokinetic interactions of carbamazepine. Carbamazepine has an important and still evolving place in the treatment of acute mania and long-term prophylaxis. It may be useful in individuals with symptoms that are not responsive to other treatments and in some subtypes of bipolar disorder that are not typically responsive to a more traditional agent such as lithium. These subtypes might include those patients with bipolar II disorder, dysphoric mania, substance abuse co-morbidity, mood incongruent delusions, and a negative family history of bipolar illness in first-degree relatives. In addition, carbamazepine may be useful in patients who do not adequately tolerate other interventions as a result of adverse effects, such as weight gain, tremor, diabetes insipidus or polycystic ovarian syndrome. We review our clinical and research experience with carbamazepine alone and in combination with lithium, valproic acid and other agents in complex combination treatment of bipolar illness. More precise clinical and biological predictors and correlates of individual clinical responsiveness to carbamazepine and other mood stabilisers are eagerly awaited.

Combination therapy in epilepsy: when and what to use

After being regarded as a last resort for over two decades, the role of combination therapy as a treatment strategy for epilepsy is undergoing re-evaluation. This is a result of the growing appreciation that all seizures cannot be controlled by monotherapy in a substantial proportion of patients, and of the development of a range of modern antiepileptic drugs (AEDs), some of which are better tolerated and less prone to complex pharmacokinetic drug interactions than their older counterparts.Robust evidence to guide clinicians on when and how to combine AEDs is lacking, and current practice recommendations are largely empirical. Monotherapy should remain the treatment of choice for newly diagnosed epilepsy. A combination of two AEDs can be considered after failure, resulting from lack of efficacy, of one or two different monotherapy regimens. A few patients will become seizure-free with a combination of three AEDs, but treatment with a combination of four or more is unlikely to be successful. There is some evidence to support a pharmacomechanistic approach to AED combination. Care should be taken to avoid excessive drug load, which is associated with increased toxicity. Bigger and better randomised, controlled studies are needed to determine the optimal time and way to combine AEDs.

A comparison of two multiple-characteristic decision-making models for the comparison of antihypertensive drug classes: Simple Additive Weighting (SAW) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS)

BACKGROUND

Multiple-characteristics decision-making (MCDM) models can be used to calculate a score, based on a set of characteristics, for a number of alternative drugs or drug classes to allow comparison between them and thus enhance evidence-based pharmacotherapy.

OBJECTIVE

To compare two MCDM models, Simple Additive Weighting (SAW) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), in determining first-line antihypertensive drug class.

METHODS

Five different classes of antihypertensive drugs were analyzed: diuretics, beta-adrenoceptor antagonists (beta-blockers), dihydropyridine calcium channel blockers (DHP-CCBs), ACE inhibitors, and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]). Four characteristics were deemed relevant for the determination of first-line antihypertensive drug class: effectiveness, persistence with treatment as a measure of tolerability, cost, and clinical experience. Weight factors were determined by sending questionnaires to cardiologists, pharmacists, general practitioners (GPs), and internists in The Netherlands. Absolute scores for the characteristics were determined from literature (effectiveness and persistence) and health insurance data (costs and clinical experience).

RESULTS

Ninety-two cardiologists (33% of those sent the questionnaire), 90 GPs (31%), 87 internists (31%), and 123 pharmacists (43%) completed the questionnaire. Among all professions, according to both SAW and TOPSIS, ACE inhibitors were ranked as the first-line antihypertensive drug class, typically followed by beta-blockers.

CONCLUSION

Both SAW and TOPIS analyses, using weight factors assigned by cardiologists, pharmacists, GPs, and internists from The Netherlands, rank ACE inhibitors as the first choice among antihypertensive drug classes for the treatment of uncomplicated hypertension. Both methods are valuable tools in the development of evidence-based pharmacotherapy.

Diagnosing and predicting refractory epilepsy

Over 30% of people with epilepsy will never achieve remission with antiepileptic drug (AED) therapy. These individuals are often severely disabled by their condition, have an unsatisfactory quality of life, and are at increased risk of sudden unexpected death. Early identification of refractory epilepsy would allow prompt referral to specialist services, where the diagnosis can be confirmed, seizures and syndromes classified, AED therapy optimized, and suitability for surgery assessed. Recent studies suggest that patients with symptomatic or cryptogenic epilepsy, those who experience multiple seizures before AED treatment initiation, and those with febrile convulsions, a family history of epilepsy, or psychiatric comorbidities are least likely to respond to drug therapy. Failure to achieve good seizure control with the first one or two AED monotherapies is usually sufficient to highlight the possibility of subsequent refractory epilepsy. For most of these individuals, combination therapy using AEDs with complementary modes of action is the recommended treatment approach.

Medical therapy of epilepsy: when to initiate treatment and when to combine?

Most patients reporting more than one well-documented or witnessed seizure require prophylactic antiepileptic (AED) therapy. Those with an underlying brain disorder and/or an abnormal electroencephalogram should probably be treated after their first event. The goal should be maintenance of a normal lifestyle by complete seizure control with no or minimal side-effects. Failure of the first AED due to lack of efficacy implies refractoriness. A policy of consecutive substitutions is unlikely to be an effective strategy. Thus, if the first or second monotherapy improves control but does not produce seizure freedom, an AED with different and perhaps multiple mechanisms of action should be added. Strategies for combining drugs should involve individual assessment of patient-related factors, including seizure type and epilepsy syndrome classifications coupled with an understanding of the pharmacology, side-effects and interaction profile of the AEDs. Reducing the dose of one or more AEDs may help accommodate the introduction of a second or third drug. An orderly approach to the pharmacological management and, when appropriate, surgical investigations for each epilepsy syndrome will optimise the chance of perfect seizure control and help more people achieve safer and more fulfilled lives.

The use of multiattribute decision models in evaluating triptan treatment options in migraine

BACKGROUND

The physician treating patients with migraine is now able to choose from among seven triptans-almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan and zolmitriptan. These differ, to greater or lesser degrees, on a range of clinical attributes important for treatment selection.

OBJECTIVE

To outline the basic principles of Multiattribute Decision Making (MADM) and describe how one such method-TOPSIS (Technique for Order Preference by Similarity to the Ideal Solution)-can be applied to evaluate the currently available triptans.

METHODS

In an example application, summary data from a recent meta-analysis of 53 published and unpublished placebo-controlled trials of the oral triptans were combined in TOPSIS models with computer-generated attribute importance weights representing the entire range of possible values, That is, the relative performance of the triptans was explored across all logically possible combinations of relative importance of the treatment attributes available from the meta-analysis, and uncertainty was assessed based on the confidence intervals from the meta-analysis.

RESULTS

When compared across the entire range of values for relative attribute importance, almotriptan, eletriptan and rizatriptan were more similar to a hypothetical ideal triptan and were more likely to appear in the top three closest to the hypothetical ideal, than were naratriptan, sumatriptan, and zolmitriptan.

CONCLUSION

Using the TOPSIS model, almotriptan, eletriptan and rizatriptan were more likely to appear in the top three closest to the hypothetical ideal triptan.

How treatment priorities influence triptan preferences in clinical practice: perspectives of migraine sufferers, neurologists, and primary care physicians

BACKGROUND

In treating migraine sufferers, physicians can choose from among seven triptans with different attributes.

OBJECTIVE

To develop a system for selecting an oral triptan based on treatment priorities of migraine sufferers, neurologists, and primary care physicians (PCPs) in the United States, and evidence-based performance of triptans in clinical trials.

METHODS

The TRIPSTAR project combines data on the treatment preferences of migraineurs and physicians with results from a meta-analysis of individual triptans, which evaluated their effectiveness on various clinical endpoints. Telephone interviews with migraine sufferers, neurol ogists, and PCPs were conducted to elicit individual views on the relative importance of a prespecified set of acute treatment outcomes. Four hundred and fifteen migraine sufferers, both triptan-experienced and triptan-naive, were interviewed. Also, 200 board-certified neurologists and 200 PCPs provided information on migraine patients from their clinical practice. A multiattribute decision model for selecting an oral triptan was constructed using attribute importance weights collected at telephone interview and the meta-analysis data, which were drawn from 53 clinical trials of 6 oral triptans.

RESULTS

Efficacy attributes were rated significantly more important than tolerability or consistency in selecting an oral triptan, according to migraine sufferers and physicians. Freedom from cardiovascular adverse events was the most important tolerability attribute, according to migraine sufferers and physicians alike. Pain free at 1 h was the most important lower-level efficacy attribute for migraine sufferers, while sustained pain free was most important for physicians. When weighted treatment attributes were combined with meta-analysis data in a multi-attribute decision model, almotriptan 12.5 mg, eletriptan 80 mg, and rizatriptan 10 mg were significantly closer to the hypothetical ideal triptan than was suma triptan 100 mg. Triptans selected by the model were generally closer to the patient-specific ideal triptan than were the triptans prescribed by physicians.

CONCLUSIONS

Almotriptan, eletriptan, and rizatriptan were the three triptans closest to the ideal, from the perspectives of migraine sufferers, PCPs, and neurologists alike. The TRIPSTAR model may be a potentially useful decision-support tool to help physicians select the triptan most likely to produce a successful outcome in migraine sufferers.

Prioritizing treatment attributes and their impact on selecting an oral triptan: Results from the TRIPSTAR project

Seven oral triptans, which differ on a range of attributes important for treatment selection, are now available for treating migraine. US neurologists were surveyed to assess the relative importance of treatment attributes, prespecified by clinical relevance and availability of controlled study data, for selecting among oral triptans. Using a multiattribute decision model, we combined these data on the importance of treatment attributes with information on the relative performance of the oral triptans derived from a recent meta-analysis of controlled clinical trials.

The natural history of epilepsy: an epidemiological view

Better information of the natural history of epilepsy has important implications for understanding the underlying neurobiology, evaluating treatment strategies, and planning healthcare resources. The traditional pessimistic view has been dispelled by results from modern community based prospective studies, showing that over 60% of newly diagnosed patients will enter remission upon treatment. Recent outcome studies suggest that medical intractability may be predicted after failure of two antiepileptic drugs. Poor prognostic factors include a high initial seizure density, symptomatic aetiology, and presence of structural cerebral abnormalities, all of which can be identified early on. Among patients who have entered remission, many will remain seizure-free after antiepileptic drug treatment is withdrawn, suggesting that the underlying seizure generating factor has remitted. Whether some of these patients have entered remission "spontaneously" is contentious because, with effective pharmacotherapy for epilepsy in use for over 100 years, the natural history of untreated epilepsy is largely unknown. Circumstantial evidence, mostly arising from resource poor countries where antiepileptic drug treatment is not readily available, indicates that spontaneous remission may occur in up to 30% of cases. Observations from these complementary sources suggest that, at the population level, prognosis of newly diagnosed epilepsy may be broadly categorised into three groups: remission without treatment, remission with treatment only, and persistent seizures despite treatment. As understanding of the prognostic factors improves, the potential of a "prognostic group specific" management approach should be explored so that effective treatments may be used in a more rational and targeted fashion.

TRIPSTAR: prioritizing oral triptan treatment attributes in migraine management

Migraine can be associated with severe pain and is often very disabling. Optimal treatment should provide rapid and sustained, complete pain relief, be well tolerated and restore normal function. The seven commercially available triptans show differences in performance on individual treatment attributes. The TRIPSTAR multiattribute decision model compares the profiles of the oral triptans, using efficacy and tolerability data weighted for importance, to identify if measurable differences are clinically relevant. Application of the TRIPSTAR model was demonstrated at the Migraine Trust International Symposium 2002, where delegates collectively prioritized treatment attributes according to the needs of a specific patient case history. The TRIPSTAR model identified the preferred triptans for this patient. These three triptans, almotriptan 12.5 mg, eletriptan 80 mg and rizatriptan 10 mg, standout in a triptan meta-analysis, three TRIPSTAR surveys and in a demonstration of the TRIPSTAR model at a symposium in the USA. Taken together the findings suggest that some differences amongst triptans may be relevant in clinical practice.

The Use of Antiepileptic Drugs-Principles and Practice

Up to 70% of people developing epilepsy may expect to become seizure free with optimum antiepileptic drug (AED) therapy. The remaining 30% are the most difficult to treat. Most patients are controlled on a single AED, but a small proportion requires a combination of two agents. Add-on therapy with a second drug, rather than substitution, may be a viable and rational approach in some patients, particularly if the first drug is relatively well tolerated. Precise classification of the type of seizures, as well as the epilepsy syndrome, together with careful recording of both seizures and adverse effects, are essential if rational management decisions are to be made. The goal of therapy should be complete seizure freedom with a single drug taken once or twice a day and without adverse effects. If control is difficult to achieve, the maximum tolerated dose of each drug should be explored, but a balance needs to be struck between adverse effects and control of seizures. In patients in whom treatment appears to be ineffective, the diagnosis of epilepsy and adherence to therapy should be reviewed. Drugs used in combination must be carefully selected, as poor adherence, drug interactions, and toxicity are more likely if more than one drug is prescribed. Agents are usually chosen according to seizure type, patient characteristics, and often by clinician preference. Those that are better tolerated have a low potential for pharmacokinetic and pharmacodynamic interactions, and those that can be easily introduced without any complicated titration schedule have an advantage.

Pharmacodynamic interaction studies with topiramate in the pentylenetetrazol and maximal electroshock seizure models

There is emerging evidence to support the efficacy of some antiepileptic drug (AED) combinations in refractory epilepsy. Definitive clinical studies are, however, difficult to perform. Experimental seizure models can be employed to identify potentially useful combinations for subsequent clinical evaluation. We have investigated the anticonvulsant effects of topiramate (TPM) in combination with 13 other AEDs in the pentylenetetrazol (PTZ) and maximal electroshock (MES) seizure models. Single drugs and combinations were administered by intraperitoneal injection and anticonvulsant effects determined at 1-hour post-dosing. TPM was without significant effect in the PTZ test. In contrast, phenobarbital, primidone, ethosuximide, sodium valproate, felbamate and tiagabine all increased the latency to the first generalised seizure. Combinations of TPM and active adjunctive drug were universally effective. Combinations of TPM with clobazam, lamotrigine and levetiracetam were also anticonvulsant, despite the inactivity of the constituent compounds when administered alone. TPM reduced the incidence of MES-induced seizures in a dose-dependent manner, as did phenobarbital, phenytoin, primidone, carbamazepine, sodium valproate, clobazam, lamotrigine, felbamate and tiagabine. All combination treatments were similarly effective. These findings suggest that combinations of TPM with lamotrigine and levetiracetam may demonstrate anticonvulsant synergism and merit further investigation in additional model systems and with recourse to more quantitative mathematical analysis.

Neurobiology of Seizures and Behavioral Abnormalities

Seizures are both caused by and induce a complex set of neurobiological alterations and adaptations. The animal model of amygdala kindling provides insight into the spatiotemporal evolution of these changes as a function of seizure development and progression. Intracellular, synaptic, and microstructural changes are revealed as related to both the primary pathophysiology of kindled seizure evolution and compensatory secondary, or endogenous anticonvulsant adaptations. At the level of gene expression, the balance of these pathological and adaptive processes (as augmented by exogenous medications) probably determines whether seizures will be manifest or suppressed and could account for aspects of their intermittency. As anxiety and emotion modulation are subserved by many of the same neuroanatomic substrates involved in the evolution of complex partial seizures, particularly those of the medial temporal lobe, it is readily conceptualized how vulnerability to a range of psychiatric disorders could be related to the primary or secondary neurochemical alterations associated with seizure disorders. The discrete and methodologically controlled elucidation of the cascades and spatiotemporal distributions of neurobiological alterations that accompany seizure evolution in the kindling model may help resolve some of the difficulty and complexity of elucidating these biobehavioral relationships in the clinic.

Drug treatment of epilepsy: when does it fail and how to optimize its use?

Although modern community-based studies have shown that a majority of people with newly diagnosed epilepsy will enter long-term remission, seizures remain refractory to treatment in a substantial proportion of this population--perhaps as much as 40%. A consensus is being reached that, for operational purposes, pharmacoresistance can be suspected when two appropriately chosen, well-tolerated, first-line antiepileptic drugs (AEDs) or one monotherapy and one combination regimen have failed due to lack of efficacy. Poor prognostic factors include lack of response to the first AED, specific syndromes, symptomatic etiology, family history of epilepsy, psychiatric comorbidity, and high frequency of seizures. These observations suggest that prognosis can often be determined early in the course of the disorder. We propose a management paradigm that aims to maximize the chance of successful AED therapy, including the early use of "rational polytherapy" for patients not responding to monotherapy, and to identify efficiently patients suitable for "curative" resective surgery, in particular those with mesial temporal lobe epilepsy. An orderly approach to each epilepsy syndrome will optimize the chance of perfect seizure control and help more patients achieve a fulfilling life.

Current limitations of antiepileptic drug therapy: a conference review

The current limitations of antiepileptic drug (AED) therapy were the topic of a discussion group meeting at the 5th European Congress on Epileptology, Madrid, 6-10 October 2002. This review contains four short papers covering the topics discussed by the speakers at this meeting and an account of the ensuing discussion with all participants. The meeting focused on four issues. (i) Are mechanisms of action of AEDs useful to predict treatment outcome? The short answer to this question was no, for several reasons. These include the fact that clinically relevant mechanisms in individual patients remain unclear, the treatment of epilepsy targets the symptoms rather than the cause of the disease, and that current seizure classification defines heterogeneous patient populations. (ii) The benefits of the often recommended titration of the dose to the maximum tolerated level when seizures persist at average AED doses. A re-evaluation of this practice showed that dose escalation achieves seizure freedom in only 1 of 4 patients with newly diagnosed epilepsy and only 1 of 10 patients with refractory epilepsy are likely to experience a greater than 50% reduction in seizure frequency. Being aware of the limited utility of maximum dose titration and subsequent dose reduction if no significant individual benefit is achieved avoids medical over-treatment with a worsening risk-benefit balance. (iii) When single drug therapy is not sufficiently effective, adding a second drug or alternative monotherapy are common options. Based on published data, there is no conclusive evidence in favour of either alternative monotherapy or second-line polytherapy. A pragmatic choice may be to evaluate the combination and then attempt to withdraw the first drug in the case of success. This may prevent the substitution of a partially efficacious drug by a non-efficacious drug. The choice of the second drug should, in theory, be based on which first drug has failed but again compelling evidence to support specific recommendations is lacking. (iv) Unexpected worsening of seizures may occur in many circumstances and has many causes, including tolerance and adverse pharmacodynamic effects of individual AEDs on seizure generating mechanisms. Patients are usually aware of aggravation and may express a "dislike" for a particular AED as a warning sign for physicians to modify the medication. The availability of numerous AEDs, particularly with single mechanisms of action, has increased the risk of paradoxical effects that may go undetected in clinical trials and only surface during astute clinical observations.

Seizure freedom with more than one antiepileptic drug

Many people with epilepsy take antiepileptic drug (AED) polytherapy, although supportive evidence for the success of this strategy is sparse. Of 2881 treated patients registered in our database, 1617 (56%) have been seizure-free for at least the previous year, with 21% taking more than one AED (287 on two, 86%; 42 on three, 13%; 3 on four, 1%). There were 40 effective duotherapies and 28 triple therapies. Treatment with two or three but not four AEDs may be a useful therapeutic option for patients not responding to monotherapy. Further explorations of the best regimens for individual seizure types and epilepsy syndromes is required.

Refractory epilepsy: a progressive, intractable but preventable condition?

Intractable seizures are just one manifestation of 'refractory epilepsy', which can be recognized as a distinct condition with multifaceted dimensions, including neurobiochemical plastic changes, cognitive decline and psychosocial dysfunction, leading to dependent behaviour and a restricted lifestyle. The biological basis of 'refractoriness' is likely to be multifactorial, and may include the severity of the syndrome and/or underlying neuropathology, abnormal reorganization of neuronal circuitry, alteration in neurotransmitter receptors, ion channelopathies, reactive autoimmunity, and impaired antiepileptic drug (AED) penetration to the seizure focus. Some of these deleterious changes may be a consequence of recurrent seizures. We hypothesize that 'refractory epilepsy' may be prevented by interrupting this self-perpetuating progression. There is increasing evidence that these patients can be identified early in the clinical course and, thus, be targeted early for effective therapeutic intervention. Failure of two first-line AEDs due to lack of efficacy or poor tolerability should prompt consideration of epilepsy surgery in a patient with a resectable brain abnormality. For the majority not suitable for 'curative' surgery, AEDs should be combined with the aim of achieving 'synergism'. This strategy has the potential to improve outcome by preventing the insidious progression to intractable 'refractoriness' and a downward spiraling quality of life.

Tripstar: a comprehensive patient-based approach to compare triptans

Several second-generation triptans have been introduced that differ in their pharmacologic profiles relative to each other and to sumatriptan. As therapeutic options multiply, clinicians must be able to distinguish among these compounds. Recently, a meta-analysis was conducted on data from 53 double-blind, randomized, placebo- or active-controlled trials involving over 24,000 patients receiving oral triptans. Results indicated that almotriptan 12.5 mg, rizatriptan 10 mg, and eletriptan 80 mg are generally superior to sumatriptan 100 mg based on individual treatment attributes, such as pain relief, sustained pain freedom, consistency of response, and tolerability. Meta-analyses are limited, however, as the analysis can only be performed for individual end points, whereas patients and prescribers balance a variety of treatment attributes when assessing drug acceptability. A flexible overall scoring system ("Tripstar") is proposed that compares triptans to a hypothetical "ideal" using meta-analysis data combined with ratings of the relative importance of clinically relevant treatment criteria. An informal test of the Tripstar model indicated that sumatriptan is most similar to a hypothetical ideal for both mild and severe migraine, primarily due to its high worldwide clinical exposure. However, after exclusion of worldwide exposure as a contributing factor, almotriptan 12.5 mg is most similar to the ideal, principally because of its good tolerability. Further tests of the Tripstar model are planned that will gauge the relative importance of a broader range of attributes.

Effectiveness of first antiepileptic drug

PURPOSE

To investigate the interaction among efficacy, tolerability, and overall effectiveness of the first antiepileptic drug (AED) in patients with newly diagnosed epilepsy.

METHODS

The 470 patients were diagnosed, treated and followed up from January 1984 at a single center. Outcome was classified as seizure freedom for at least the last year or failure of initial treatment because of inadequate seizure control, adverse events, or for other reasons.

RESULTS

Overall, 47% of patients became seizure-free with the first prescribed AED. A higher proportion (p = 0.025) of patients with symptomatic or cryptogenic epilepsy changed treatment because of intolerable side effects (17%), and a lower proportion (p = 0.007) became seizure-free (43.5%) compared with those with idiopathic epilepsy (8.5% and 58%, respectively). Most patients (83%) received carbamazepine (CBZ; n = 212), sodium valproate (VPA; n = 101), or lamotrigine (LTG; n = 78). The majority of seizure-free patients required only a moderate daily AED dose (93.1% with < or =800 mg CBZ, 91.3% with < or =1,500 mg VPA, 93.8% with < or =300 mg LTG), with commonest dose ranges being 400-600 mg for CBZ, 600-1,000 mg for VPA, and 125-200 mg for LTG. Most withdrawals due to poor tolerability also occurred at or below these dose levels (CBZ: 98%; VPA: 100%; LTG: 75%). Patients taking CBZ (27%) had a higher incidence of adverse events necessitating a change of treatment than did those treated with VPA (13%) or LTG (10%), resulting in fewer becoming seizure-free (CBZ vs. VPA, p = 0.02; CBZ vs. LTG, p = 0.002).

CONCLUSIONS

Nearly 50% of newly diagnosed patients became seizure-free on the first-ever AED, with >90% doing so at moderate or even modest dosing. Tolerability was as important as efficacy in determining overall effectiveness.