Pregabalin monotherapy for epilepsy
ABSTRACT Many people with epilepsy suffer from poorly controlled seizures, despite current antiepileptic treatments. Due to high rates of treatment resistance, there is interest in new pharmacological treatment options such as pregabalin. However, it remains unclear whether existing evidence of pregabalin is rigorous enough to support its monotherapy.
To determine the efficacy and tolerability of pregabalin in people with epilepsy.
We searched the Cochrane Epilepsy Group's Specialized Register (August 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 7 ), MEDLINE (1946 to August week 1, 2012), EMBASE (1974 to August 2012) and the Chinese Biomedical Literature Database (CBM) (1978 to August 2012). No language restrictions were imposed.
Randomised controlled trials (RCTs) comparing pregabalin with placebo or another antiepileptic drug monotherapy for epilepsy.
Two review authors (QZ and LY) independently extracted trial data and assessed trial quality. We assessed the following outcomes: (1) time to withdrawal after randomisation; (2) time to achieve six-, 12- or 24-month remission; (3) the proportion of participants who remained seizure-free for six or more continuous months; (4) time to first seizure after randomisation; (5) validated quality of life measures; (6) health economic outcomes; (7) adverse effects. We expressed time-to-event outcomes as hazard ratios (HRs) with 95% confidence interval (CI), where an HR > 1 indicates an event is more likely to occur earlier on pregabalin than the comparator.
Two short-term studies involving 753 participants met the inclusion criteria. Only one study investigated the effects of pregabalin compared with lamotrigine in patients with newly diagnosed partial seizures, and the other study investigated the effects of pregabalin compared with gabapentin in hospitalised patients with refractory partial epilepsy. There were no studies on generalised-onset tonic-clonic seizures (with or without other generalised seizure types).We found that pregabalin was inferior in comparison to lamotrigine when measuring time to withdrawal due to inadequate seizure control after dose stabilisation from randomisation: hazard ratio (HR) 4.52; 95% confidence interval (CI) 1.93 to 10.60; time to achieve six-month remission after dose stabilisation from randomisation: HR 0.56; 95% CI 0.41 to 0.76; the proportion of participants who remained seizure-free for six or more continuous months: RR 0.76, 95% CI 0.67 to 0.87 (Europe: 0.83, 95% CI 0.69 to 0.99; Asia: RR 0.70, 95% CI 0.57 to 0.86; the Americas: RR 0.62, 95% CI 0.33 to 1.19); and time to first seizure after dose stabilisation from randomisation: HR 1.74; 95% CI 1.26 to 2.39. There was no significant difference in safety-related outcomes between pregabalin and lamotrigine, but more participants in the pregabalin group developed somnolence, weight increase and convulsion. Pregabalin was better than gabapentin when measuring time to withdrawal due to all reasons after randomisation: HR 0.25; 95% CI 0.11 to 0.57; and time to withdrawal due to inadequate seizure control after randomisation: HR 0.41; 95% CI 0.18 to 0.92. No significant difference was found in safety-related outcomes between pregabalin and gabapentin. But we found some limitations in the study design which may have had an influence on the results.
Pregabalin seems to have similar tolerability but inferior efficacy in comparison to lamotrigine for newly diagnosed partial seizures. However, considering the limitations in the study design (such as the short-term follow-up and the low initial target dose selection), the results should be interpreted with caution. The available data were too limited to draw any conclusions between pregabalin and gabapentin. The result indicated that the treatment effects were influenced by the study regions. The clinical disadvantage of pregabalin was more prominent in Asia when compared with lamotrigine. We should determine whether pregabalin has ethnic differences in the treatment of epilepsy in the future. This review does not inform any treatment policy for patients with generalized onset tonic-clonic seizures. Further long-term trials are needed to investigate the genuine effectiveness of pregabalin as monotherapy.
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ABSTRACT: Efficacious and safe monotherapy options are needed for adult patients with newly diagnosed epilepsy. As an adjunctive treatment for partial seizures, pregabalin compares favourably with lamotrigine and is an effective, approved treatment. We studied the efficacy and safety of pregabalin as monotherapy, using a design that complied with European regulatory requirements and International League Against Epilepsy guidelines. This phase 3, double-blind, randomised, non-inferiority study compared the efficacy and tolerability of pregabalin and lamotrigine monotherapy in patients with newly diagnosed partial seizures at 105 centres, mostly in Europe and Asia. Randomisation to treatment groups (1:1 ratio) was by a computer-generated pseudorandom code (random permuted blocks), with patients sequentially assigned numbers by telephone. Investigators, site staff, and patients were masked to the assigned treatment. After randomisation, patients were titrated to either 75 mg oral pregabalin or 50 mg oral lamotrigine twice daily during a 4-week dose-escalation phase, followed by a 52-week efficacy assessment phase during which the daily dose could be increased as needed to a maximum of 600 mg and 500 mg, respectively. The primary efficacy endpoint was the proportion of patients who remained seizure-free for 6 or more continuous months during the efficacy assessment phase; analysis included all patients who were randomly assigned to treatment groups and received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, number NCT00280059. 660 patients were randomly assigned to treatment groups (330 pregabalin, 330 lamotrigine), of whom 622 entered the efficacy assessment phase (314 pregabalin, 308 lamotrigine). Fewer patients in the pregabalin group than in the lamotrigine group became seizure-free for 6 or more continuous months (162 [52%] vs 209 [68%]; difference in proportion, -0·16, 95% CI -0·24 to -0·09). The overall incidence of adverse events was similar between the groups and consistent with that in previous studies; dizziness (55 [17%] vs 45 [14%] patients), somnolence (29 [9%] vs 14 [4%]), fatigue (27 [8%] vs 19 [6%]), and weight increase (21 [6%] vs 7 [2%]) were numerically more common in the pregabalin group than in the lamotrigine group. Pregabalin has similar tolerability but seems to have inferior efficacy to lamotrigine for the treatment of newly diagnosed partial seizures in adults. Inferior efficacy of pregabalin might have been attributable to limitations in the study design, as treatment doses might have not been optimised adequately or early enough. Pfizer Inc.The Lancet Neurology 08/2011; 10(10):881-90. DOI:10.1016/S1474-4422(11)70154-5 · 21.90 Impact Factor
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ABSTRACT: Unverricht-Lundborg disease (ULD), progressive myoclonic epilepsy type 1 (EPM1, OMIM254800), is an autosomal recessively inherited neurodegenerative disorder characterized by age of onset from 6 to 16 years, stimulus-sensitive myoclonus, and tonic-clonic epileptic seizures. Some years after the onset ataxia, incoordination, intentional tremor, and dysarthria develop. Individuals with EPM1 are mentally alert but show emotional lability, depression, and mild decline in intellectual performance over time. The diagnosis of EPM1 can be confirmed by identifying disease-causing mutations in a cysteine protease inhibitor cystatin B (CSTB) gene. Symptomatic pharmacologic and rehabilitative management, including psychosocial support, are the mainstay of EPM1 patients' care. Valproic acid, the first drug of choice, diminishes myoclonus and the frequency of generalized seizures. Clonazepam and high-dose piracetam are used to treat myoclonus, whereas levetiracetam seems to be effective for both myoclonus and generalized seizures. There are a number of agents that aggravate clinical course of EPM1 such as phenytoin aggravating the associated neurologic symptoms or even accelerating cerebellar degeneration. Sodium channel blockers (carbamazepine, oxcarbazepine) and GABAergic drugs (tiagabine, vigabatrin) as well as gabapentin and pregabalin may aggravate myoclonus and myoclonic seizures. EPM1 patients need lifelong clinical follow-up, including evaluation of the drug-treatment and comprehensive rehabilitation.Epilepsia 05/2008; 49(4):549-56. DOI:10.1111/j.1528-1167.2008.01546.x · 4.57 Impact Factor
Article: Pregabalin: A new anxiolytic[Show abstract] [Hide abstract]
ABSTRACT: Pregabalin (S-[+]-3-isobutylgaba) was designed as a lipophilic GABA (gamma-aminobutyric acid) analogue substituted at the 3'-position in order to facilitate diffusion across the blood-brain barrier. It was originally developed as an anticonvulsant agent, however it has been shown to be effective in the treatment of several disorders including hyperalgesia and behavioural disorders. Although its exact mode of action remains unclear, pregabalin interacts with the same binding site and has a similar pharmacological profile as its predecessor, gabapentin (1-[aminomethyl] cyclohexane acetic acid). Its main site of action appears to be on the alpha(2)delta subunit of voltage-dependent calcium channels, widely distributed throughout the peripheral and central nervous system. Pregabalin appears to produce an inhibitory modulation of neuronal excitability. In healthy volunteers, it is rapidly absorbed with peak blood concentrations within 1 h and it has a bioavailability of approximately 90%. In preclinical trials of anticonvulsant activity, pregabalin is three to ten times more potent than gabapentin. It is well-tolerated and associated with dose-dependent adverse effects (ataxia, dizziness, headache and somnolence) that are mild-to-moderate and usually transient. There are no known pharmacokinetic drug-drug interactions reported to date. Preliminary animal and human studies showed beneficial effects in both ethological and conflict models of anxiety, as well as having some sleep-modulating properties. In Phase II and III trials, pregabalin shows promising anxiolytic action when compared to placebo in generalised anxiety disorder, social phobia and panic disorder.Expert Opinion on Investigational Drugs 05/2003; 12(4):663-72. DOI:10.1517/135437188.8.131.523 · 5.53 Impact Factor