Patterns of lamotrigine use in daily clinical practice during the first 5 years after introduction in the Netherlands

Anti-epileptic drug changes and quality of life in the community

OBJECTIVE

Changes in anti-epileptic drug (AED) regimens may indicate unsatisfactory treatment results such as insufficient seizure control or adverse effects. This inference underlies epilepsy management and research, yet current studies often do not account for AED changes. We assessed AED change patterns and their association with quality of life (QoL), as main outcome measure, in a community-based setting.

METHODS

We assessed a cohort of 248 people with epilepsy identified from community pharmacy records from whom we retrieved AED dispensing history. We assessed all changes in AED use during the 2 years prior to the index date and current QoL using the validated Dutch QOLIE-31 questionnaire.

RESULTS

Thirty-one per cent had at least one AED change during the study period, either in drug type or dose. People who changed showed significantly lower QoL (QOLIE score 73 vs 79), especially those who intensified their treatment. Each additional change was associated with a further reduction of 4.9 points in QoL score.

CONCLUSIONS

AED changes are common practice, even in people with long-standing epilepsy. Frequent changes, as objective measure of epilepsy severity, are associated with a progressively lower QoL. Changes, even in dose, should be monitored in daily clinical practice and used as a red flag that may require adjustments in epilepsy management. This may include earlier referral to a specialized centre for a more thorough evaluation or counselling. AED changes can also be used as an outcome marker in epilepsy research as a proxy of QoL for better translation of drug-efficacy results to general practice.

Continuation rates of levetiracetam in children from the EULEVp cohort study

BACKGROUND

Since indication extension to children data regarding the effectiveness of levetiracetam in paediatric patients remains limited.

AIMS

Investigate the real-life effectiveness of levetiracetam in paediatric patients.

METHODS

Epileptic children (<16 years) who had initiated levetiracetam between 1 October 2006 and 31 March 2007 were included and followed for 1 year by hospital or non-hospital neurologists practising in France.

RESULTS

Among the 156 identified children, 147 were analysed: 51.7% were female, and mean (SD) age was 9.2 years (4.2). Most patients had either partial symptomatic (30.6%) or partial cryptogenic (26.5%) epilepsy, 92.5% experienced seizures during the 6 months preceding levetiracetam initiation, and 19.2% were on levetiracetam alone at initiation. One-year levetiracetam continuation rate was estimated to be 72.0% (95%CI [63.8; 78.6]). Of the 104 children continuing levetiracetam treatment at end of study, 31.7% were seizure-free during the last six months of follow-up, and 23.1% on levetiracetam alone. Discontinuation of levetiracetam (n = 41) was mainly for insufficient efficacy (58.5% of those concerned).

CONCLUSIONS

In real-life clinical practice important treatment retention and non-negligible reduction of seizure frequency may be expected.

The EULEV cohort study: rates of and factors associated with continuation of levetiracetam after 1 year

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Levetiracetam has shown good safety/tolerability and efficacy in regulatory trials. This was confirmed in observational investigations performed soon after marketing by using continuation or retention rates as a composite measure. When an anti-epileptic drug first becomes available; however, there is evidence of channelling to more severe patients than thereafter.

WHAT THIS STUDY ADDS

This study was performed several years after marketing of levetiracetam and found high rates of continuation. It also further explores this measure by determining the continuation in the absence of initiation of additional anti-epileptic drugs.

AIMS

To investigate real-life effectiveness of levetiracetam in patients initiating treatment in a stable market situation.

METHODS

Epileptic adults who had initiated levetiracetam between 1 January and 31 August in 2005 or 2006 were included and followed for 1 year by hospital or nonhospital neurologists practising in France. One-year continuation rates were estimated using Kaplan-Meier analysis. Among those still treated at end of study, treatment goals were investigated. Factors associated with discontinuation were investigated using Cox proportional hazards regression.

RESULTS

A total of 794 subjects were included in the cohort, and 753 subjects were followed up and included in the analysis. Among these, mean (SD) age was 42.6 (±17.0) years, 51.1% were female, 76.6% had partial epilepsy, 93.5% had seizures in the 6 months preceding levetiracetam initiation and 82.9% had at least one concomitant anti-epileptic drug when starting levetiracetam. One-year levetiracetam continuation rate was 83.5% (95% confidence interval, 80.5-86.0%). Of the 579 patients still using levetiracetam at end of study, 46.8% were seizure free during the last 6 months, and 24% were on levetiracetam monotherapy. Reasons for discontinuation (n= 122) were adverse events (45%), lack of efficacy (38%) or both (9%). Levetiracetam discontinuation was most strongly associated with previous exposure to more than four anti-epileptic drugs, whereas continuation was most strongly associated with presence of seizure-related falls in the 6 months preceding levetiracetam initiation.

CONCLUSIONS

This population-based cohort study in a stable market situation found a high 1 year levetiracetam continuation rate compared with previous studies done sooner after market introduction.

Measuring outcomes of treatment with antiepileptic drugs in clinical trials

Epilepsy often requires life-long treatment with antiepileptic drugs (AEDs). For clinicians to meet the challenges of patient management, data on AED performance based on clearly defined and consistently applied outcome measures are needed. Ideally, the design of AED clinical trials should be relevant to real-world settings, providing reliable, valid, and comprehensive information on efficacy, tolerability, and quality of life (QOL). Several types of outcome parameters have been employed: percent seizure reduction, responder rate based on > or =50% seizure reduction, seizure-free rate, time to first seizure, time to Nth seizure, adverse events, QOL, retention, and compliance. Each provides important information about a drug's performance. Here we define and review endpoints for measuring AED treatment success and explore the concepts of efficacy, tolerability, QOL, retention, and compliance as well as their usefulness as clinical trial endpoints.

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.

An audit of lamotrigine, levetiracetam and topiramate usage for epilepsy in a district general hospital

The aim of this audit was to ascertain outcomes for people who had taken or who were still taking three "new generation" broad-spectrum antiepileptic drugs (AEDs), namely lamotrigine, levetiracetam and topiramate. Thirteen percent of people became seizure free and approximately, one-third had a reduction of greater than 50% in their seizures. Two-thirds of people were still taking their audit AED. In addition, approximately one-third of people with a learning disability derived substantial benefit, although the rate of seizure freedom was lower. All three AEDs were most successful at treating primary generalised epilepsy and least successful with symptomatic generalised epilepsy. With some reservations the data suggests that levetiracetam and topiramate are the most efficacious AEDs, but topiramate is the least well tolerated. These results mean consideration of a "general prescribing policy" is important when using and choosing these AEDs. We conclude that lamotrigine, levetiracetam and topiramate are useful additions to the armamentarium of AEDs.

Effectiveness of lamotrigine in clinical practice: Results of a retrospective population-based study

OBJECTIVE

Evaluation of the effectiveness of lamotrigine in a population-based cohort of epilepsy patients.

METHODS

Medical charts of 360 patients treated in 37 centres in The Netherlands were reviewed. Effectiveness of lamotrigine therapy was assessed during the first year of use, with patients serving as their own controls. Effectiveness was measured by reduction in seizure frequency and retention time.

RESULTS

Effectiveness could only be assessed in 165 patients; assessment in remaining patients was not possible due to various reasons, such as insufficient medical chart information. Lamotrigine was effective in 40% of patients who had been prescribed lamotrigine because of insufficient seizure control (n=112), and 14% of these 112 patients became seizure free. Duration of epilepsy, baseline seizure frequency, valproate use, drug load and number of antiepileptic drugs (AED) used were related to effectiveness of lamotrigine. In this group, 36% continued lamotrigine (LTG) throughout the first year without experiencing a >50% seizure reduction. Lamotrigine was effective in 63% of patients who received the drug because of poor tolerability of other antiepileptic drugs (n=53).

DISCUSSION

Lamotrigine is an effective drug in clinical practice. Use of retention time measures only may not correctly reflect the efficacy of antiepileptic drugs.

Recruitment of a cohort of lamotrigine users through community pharmacists: differences between patients who gave informed consent and those who did not

OBJECTIVE

Community pharmacists may function as intermediaries in the recruitment of a population-based cohort of patients using specific drugs. In this study, baseline characteristics and the retention rate of patients that gave informed consent, refused and did not answer were compared.

METHODS

A total of 1819 patients using the new antiepileptic drug (AED) lamotrigine were asked to provide informed consent for a retrospective chart study via their individual pharmacist. Four possible reactions resulted from the consent question: active consent, active refusal, passive refusal and non-informed. Patient characteristics and lamotrigine retention rate of the different groups were compared.

RESULTS

Pharmacists did not inform a total of 183 patients (10%). Of the remaining patients, a total of 968 (59%) gave consent; 101 (6%) actively refused and 567 (35%) did not respond. Age, burden of illness, psychotropic co-medication and continuation of lamotrigine therapy were related to active consent. Lamotrigine retention rate in patients that gave consent was higher than in other patients.

CONCLUSIONS

Patient recruitment with community pharmacists as intermediaries for observational studies on the effects of (new) drugs is feasible, and allows access to a broad population of patients. The recruitment procedure, however, may lead to selection bias.