Pharmacotherapy for adults with alcohol use disorders in outpatient settings: a systematic review and meta-analysis

IMPORTANCE

Alcohol use disorders cause substantial morbidity and early mortality yet remain greatly undertreated. Medications are considerably underused.

OBJECTIVE

To conduct a systematic review and meta-analysis of the benefits and harms of medications (US FDA-approved and others) for adults with alcohol use disorders.

DATA SOURCES

PubMed, Cochrane Library, PsycINFO, CINAHL, EMBASE, FDA website, and clinical trials registries (January 1, 1970, to March 1, 2014).

STUDY SELECTION

Two reviewers selected randomized clinical trials (RCTs) with at least 12 weeks' duration that reported eligible outcomes and head-to-head prospective cohort studies reporting health outcomes or harms.

DATA EXTRACTION AND SYNTHESIS

We conducted meta-analyses using random-effects models and calculated numbers needed to treat for benefit (NNTs) or harm (NNHs).

MAIN OUTCOMES AND MEASURES

Alcohol consumption, motor vehicle crashes, injuries, quality of life, function, mortality, and harms.

RESULTS

We included 122 RCTs and 1 cohort study (total 22,803 participants). Most assessed acamprosate (27 studies, n = 7519), naltrexone (53 studies, n = 9140), or both. The NNT to prevent return to any drinking for acamprosate was 12 (95% CI, 8 to 26; risk difference [RD], -0.09; 95% CI, -0.14 to -0.04) and was 20 (95% CI, 11 to 500; RD, -0.05; 95% CI, -0.10 to -0.002) for oral naltrexone (50 mg/d). The NNT to prevent return to heavy drinking was 12 (95% CI, 8 to 26; RD -0.09; 95% CI, -0.13 to -0.04) for oral naltrexone (50 mg/d). Meta-analyses of trials comparing acamprosate to naltrexone found no statistically significant difference between them for return to any drinking (RD, 0.02; 95% CI, -0.03 to 0.08) or heavy drinking (RD, 0.01; 95% CI, -0.05 to 0.06). For injectable naltrexone, meta-analyses found no association with return to any drinking (RD, -0.04; 95% CI, -0.10 to 0.03) or heavy drinking (RD, -0.01; 95% CI, -0.14 to 0.13) but found an association with reduction in heavy drinking days (weighted mean difference [WMD], -4.6%; 95% CI, -8.5% to -0.56%). Among medications used off-label, moderate evidence supports an association with improvement in some consumption outcomes for nalmefene (heavy drinking days per month: WMD, -2.0; 95% CI, -3.0 to -1.0; drinks per drinking day: WMD, -1.02; 95% CI, -1.77 to -0.28) and topiramate (% heavy drinking days: WMD, -9.0%; 95% CI, -15.3% to -2.7%; drinks per drinking day: WMD, -1.0; 95% CI, -1.6 to -0.48). For naltrexone and nalmefene, NNHs for withdrawal from trials due to adverse events were 48 (95% CI, 30 to 112) and 12 (95% CI, 7 to 50), respectively; risk was not significantly increased for acamprosate or topiramate.

CONCLUSIONS AND RELEVANCE

Both acamprosate and oral naltrexone were associated with reduction in return to drinking. When directly compared with one another, no significant differences were found between acamprosate and naltrexone for controlling alcohol consumption. Factors such as dosing frequency, potential adverse events, and availability of treatments may guide medication choice.

The SANAD study of effectiveness of valproate, lamotrigine, or topiramate for generalised and unclassifiable epilepsy: an unblinded randomised controlled trial

BACKGROUND

Valproate is widely accepted as a drug of first choice for patients with generalised onset seizures, and its broad spectrum of efficacy means it is recommended for patients with seizures that are difficult to classify. Lamotrigine and topiramate are also thought to possess broad spectrum activity. The SANAD study aimed to compare the longer-term effects of these drugs in patients with generalised onset seizures or seizures that are difficult to classify.

METHODS

SANAD was an unblinded randomised controlled trial in hospital-based outpatient clinics in the UK. Arm B of the study recruited 716 patients for whom valproate was considered to be standard treatment. Patients were randomly assigned to valproate, lamotrigine, or topiramate between Jan 12, 1999, and Aug 31, 2004, and follow-up data were obtained up to Jan 13, 2006. Primary outcomes were time to treatment failure, and time to 1-year remission, and analysis was by both intention to treat and per protocol. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN38354748.

FINDINGS

For time to treatment failure, valproate was significantly better than topiramate (hazard ratio 1.57 [95% CI 1.19-2.08]), but there was no significant difference between valproate and lamotrigine (1.25 [0.94-1.68]). For patients with an idiopathic generalised epilepsy, valproate was significantly better than both lamotrigine (1.55 [1.07-2.24] and topiramate (1.89 [1.32-2.70]). For time to 12-month remission valproate was significantly better than lamotrigine overall (0.76 [0.62-0.94]), and for the subgroup with an idiopathic generalised epilepsy 0.68 (0.53-0.89). But there was no significant difference between valproate and topiramate in either the analysis overall or for the subgroup with an idiopathic generalised epilepsy.

INTERPRETATION

Valproate is better tolerated than topiramate and more efficacious than lamotrigine, and should remain the drug of first choice for many patients with generalised and unclassified epilepsies. However, because of known potential adverse effects of valproate during pregnancy, the benefits for seizure control in women of childbearing years should be considered.

Association of Pharmacological Treatments for Obesity With Weight Loss and Adverse Events: A Systematic Review and Meta-analysis

IMPORTANCE

Five medications have been approved for the management of obesity, but data on comparative effectiveness are limited.

OBJECTIVE

To compare weight loss and adverse events among drug treatments for obesity using a systematic review and network meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane Central from inception to March 23, 2016; clinical trial registries.

STUDY SELECTION

Randomized clinical trials conducted among overweight and obese adults treated with US Food and Drug Administration-approved long-term weight loss agents (orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, or liraglutide) for at least 1 year compared with another active agent or placebo.

DATA EXTRACTION AND SYNTHESIS

Two investigators identified studies and independently abstracted data using a predefined protocol. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed using surface under the cumulative ranking (SUCRA) probabilities. Quality of evidence was assessed using GRADE criteria.

MAIN OUTCOMES AND MEASURES

Proportions of patients with at least 5% weight loss and at least 10% weight loss, magnitude of decrease in weight, and discontinuation of therapy because of adverse events at 1 year.

RESULTS

Twenty-eight randomized clinical trials with 29 018 patients (median age, 46 years; 74% women; median baseline body weight, 100.5 kg; median baseline body mass index, 36.1) were included. A median 23% of placebo participants had at least 5% weight loss vs 75% of participants taking phentermine-topiramate (odds ratio [OR], 9.22; 95% credible interval [CrI], 6.63-12.85; SUCRA, 0.95), 63% of participants taking liraglutide (OR, 5.54; 95% CrI, 4.16-7.78; SUCRA, 0.83), 55% taking naltrexone-bupropion (OR, 3.96; 95% CrI, 3.03-5.11; SUCRA, 0.60), 49% taking lorcaserin (OR, 3.10; 95% CrI, 2.38-4.05; SUCRA, 0.39), and 44% taking orlistat (OR, 2.70; 95% CrI, 2.34-3.09; SUCRA, 0.22). All active agents were associated with significant excess weight loss compared with placebo at 1 year-phentermine-topiramate, 8.8 kg (95% CrI, -10.20 to -7.42 kg); liraglutide, 5.3 kg (95% CrI, -6.06 to -4.52 kg); naltrexone-bupropion, 5.0 kg (95% CrI, -5.94 to -3.96 kg); lorcaserin, 3.2 kg (95% CrI, -3.97 to -2.46 kg); and orlistat, 2.6 kg (95% CrI, -3.04 to -2.16 kg). Compared with placebo, liraglutide (OR, 2.95; 95% CrI, 2.11-4.23) and naltrexone-bupropion (OR, 2.64; 95% CrI, 2.10-3.35) were associated with the highest odds of adverse event-related treatment discontinuation. High attrition rates (30%-45% in all trials) were associated with lower confidence in estimates.

CONCLUSIONS AND RELEVANCE

Among overweight or obese adults, orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide, compared with placebo, were each associated with achieving at least 5% weight loss at 52 weeks. Phentermine-topiramate and liraglutide were associated with the highest odds of achieving at least 5% weight loss.

Topiramate for migraine prevention: a randomized controlled trial

CONTEXT

Small open-label and controlled trials suggest that the antiepileptic drug topiramate is effective for migraine prevention.

OBJECTIVE

To assess the efficacy and safety of topiramate for migraine prevention in a large controlled trial.

DESIGN, SETTING, AND PATIENTS

A 26-week, randomized, double-blind, placebo-controlled study was conducted during outpatient treatment at 52 North American clinical centers. Patients were aged 12 to 65 years and had a 6-month history of migraine (International Headache Society criteria) and 3 to 12 migraines a month but no more than 15 headache days a month during a 28-day prospective baseline phase.

INTERVENTIONS

After a washout period, patients meeting entry criteria were randomized to topiramate (50, 100, or 200 mg/d) or placebo. Topiramate was titrated by 25 mg/wk for 8 weeks to the assigned or maximum tolerated dose, whichever was less. Patients continued receiving that dose for 18 weeks.

MAIN OUTCOME MEASURES

The primary efficacy measure was change from baseline in mean monthly migraine frequency. Secondary efficacy measures included responder rate (proportion of patients with > or =50% reduction in monthly migraine frequency), reductions in mean number of monthly migraine days, severity, duration, and days a month requiring rescue medication, and adverse events. The month of onset of preventive treatment action was assessed.

RESULTS

Of 483 patients randomized, 468 provided at least 1 postbaseline efficacy assessment and comprised the intent-to-treat population. Mean monthly migraine frequency decreased significantly for patients receiving topiramate at 100 mg/d (-2.1, P =.008) and topiramate at 200 mg/d (-2.4, P<.001) vs placebo (-1.1). Statistically significant reductions (P<.05) occurred within the first month with topiramate at 100 and 200 mg/d. The responder rate was significantly greater with topiramate at 50 mg/d (39%, P =.01), 100 mg/d (49%, P<.001), and 200 mg/d (47%, P<.001) vs placebo (23%). Reductions in migraine days were significant for the 100-mg/d (P =.003) and 200-mg/d (P<.001) topiramate groups. Rescue medication use was reduced in the 100-mg/d (P =.01) and 200-mg/d (P =.005) topiramate groups. Adverse events resulting in discontinuation in the topiramate groups included paresthesia, fatigue, and nausea.

CONCLUSION

Topiramate showed significant efficacy in migraine prevention within the first month of treatment, an effect maintained for the duration of the double-blind phase.

Two-year sustained weight loss and metabolic benefits with controlled-release phentermine/topiramate in obese and overweight adults (SEQUEL): a randomized, placebo-controlled, phase 3 extension study

BACKGROUND

Obesity is a serious chronic disease. Controlled-release phentermine/topiramate (PHEN/TPM CR), as an adjunct to lifestyle modification, has previously shown significant weight loss compared with placebo in a 56-wk study in overweight and obese subjects with ≥2 weight-related comorbidities.

OBJECTIVE

This study evaluated the long-term efficacy and safety of PHEN/TPM CR in overweight and obese subjects with cardiometabolic disease.

DESIGN

This was a placebo-controlled, double-blind, 52-wk extension study; volunteers at selected sites continued with original randomly assigned treatment [placebo, 7.5 mg phentermine/46 mg controlled-release topiramate (7.5/46), or 15 mg phentermine/92 mg controlled-release topiramate (15/92)] to complete a total of 108 wk. All subjects participated in a lifestyle-modification program.

RESULTS

Of 866 eligible subjects, 676 (78%) elected to continue in the extension. Overall, 84.0% of subjects completed the study, with similar completion rates between treatment groups. At week 108, PHEN/TPM CR was associated with significant, sustained weight loss (intent-to-treat with last observation carried forward; P < 0.0001 compared with placebo); least-squares mean percentage changes from baseline in body weight were -1.8%, -9.3%, and -10.5% for placebo, 7.5/46, and 15/92, respectively. Significantly more PHEN/TPM CR-treated subjects at each dose achieved ≥5%, ≥10%, ≥15%, and ≥20% weight loss compared with placebo (P < 0.001). PHEN/TPM CR improved cardiovascular and metabolic variables and decreased rates of incident diabetes in comparison with placebo. PHEN/TPM CR was well tolerated over 108 wk, with reduced rates of adverse events occurring between weeks 56 and 108 compared with rates between weeks 0 and 56.

CONCLUSION

PHEN/TPM CR in conjunction with lifestyle modification may provide a well-tolerated and effective option for the sustained treatment of obesity complicated by cardiometabolic disease. This trial was registered at clinicaltrials.gov as NCT00796367.

Controlled-release phentermine/topiramate in severely obese adults: a randomized controlled trial (EQUIP)

A 56-week randomized controlled trial was conducted to evaluate safety and efficacy of a controlled-release combination of phentermine and topiramate (PHEN/TPM CR) for weight loss (WL) and metabolic improvements. Men and women with class II and III obesity (BMI ≥ 35 kg/m(2)) were randomized to placebo, PHEN/TPM CR 3.75/23 mg, or PHEN/TPM CR 15/92 mg, added to a reduced-energy diet. Primary end points were percent WL and proportions of patients achieving 5% WL. Secondary end points included waist circumference (WC), systolic and diastolic blood pressure (BP), fasting glucose, and lipid measures. In the primary analysis (randomized patients with at least one postbaseline weight measurement who took at least one dose of assigned drug or placebo), patients in the placebo, 3.75/23, and 15/92 groups lost 1.6%, 5.1%, and 10.9% of baseline body weight (BW), respectively, at 56 weeks (P < 0.0001). In categorical analysis, 17.3% of placebo patients, 44.9% of 3.75/23 patients, and 66.7% of 15/92 patients, lost at least 5% of baseline BW at 56 weeks (P < 0.0001). The 15/92 group had significantly greater changes relative to placebo for WC, systolic and diastolic BP, fasting glucose, triglycerides, total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL). The most common adverse events were paresthesia, dry mouth, constipation, dysgeusia, and insomnia. Dropout rate from the study was 47.1% for placebo patients, 39.0% for 3.75/23 patients, and 33.6% of 15/92 patients. PHEN/TPM CR demonstrated dose-dependent effects on weight and metabolic variables in the direction expected to be beneficial with no evidence of serious adverse events induced by treatment.

Topiramate in Migraine Prevention

BACKGROUND

Open-label trials and small controlled studies report topiramate's efficacy in migraine prevention.

OBJECTIVE

To assess the efficacy and safety of topiramate as a migraine-preventive therapy.

DESIGN

A 26-week, randomized, double-blind, placebo-controlled study.

SETTING

Outpatient treatment at 49 US clinical centers. Patients Patients were aged 12 to 65 years, had a 6-month International Headache Society migraine history, and experienced 3 to 12 migraines per month, but had 15 or fewer headache days per month during the 28-day baseline period.

INTERVENTIONS

Participants were randomized to placebo or topiramate, 50, 100, or 200 mg/d, titrated by 25 mg/wk to the assigned dose or as tolerated in 8 weeks; maintenance therapy continued for 18 weeks.

MAIN OUTCOME MEASURES

The primary efficacy assessment was a reduction in mean monthly migraine frequency across the 6-month treatment phase. Secondary end points were responder rate, time to onset of action, mean change in migraine days per month, and mean change in rescue medication days per month.

RESULTS

Four hundred eighty-seven patients were randomized, and 469 composed the intent-to-treat population. The mean +/- SD monthly migraine frequency decreased significantly for the 100-mg/d group (from 5.4 +/- 2.2 to 3.3 +/- 2.9; P <.001) and the 200-mg/d group (from 5.6 +/- 2.6 to 3.3 +/- 2.9; P <.001) vs the placebo group (from 5.6 +/- 2.3 to 4.6 +/- 3.0); improvements occurred within the first treatment month. Significantly more topiramate-treated patients (50 mg/d, 35.9% [P =.04]; 100 mg/d, 54.0% [P <.001]; and 200 mg/d, 52.3% [P <.001]) exhibited a 50% or more reduction in monthly migraine frequency than placebo-treated patients (22.6%). Adverse events included paresthesia, fatigue, nausea, anorexia, and taste per version.

CONCLUSION

Topiramate, 100 or 200 mg/d, was effective as a preventive therapy for patients with migraine.

Topiramate for treating alcohol dependence: a randomized controlled trial

CONTEXT

Hypothetically, topiramate can improve drinking outcomes among alcohol-dependent individuals by reducing alcohol's reinforcing effects through facilitation of gamma-aminobutyric acid function and inhibition of glutaminergic pathways in the corticomesolimbic system.

OBJECTIVE

To determine if topiramate is a safe and efficacious treatment for alcohol dependence.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, randomized, placebo-controlled, 14-week trial of 371 men and women aged 18 to 65 years diagnosed with alcohol dependence, conducted between January 27, 2004, and August 4, 2006, at 17 US sites.

INTERVENTIONS

Up to 300 mg/d of topiramate (n = 183) or placebo (n = 188), along with a weekly compliance enhancement intervention.

MAIN OUTCOME MEASURES

Primary efficacy variable was self-reported percentage of heavy drinking days. Secondary outcomes included other self-reported drinking measures (percentage of days abstinent and drinks per drinking day) along with the laboratory measure of alcohol consumption (plasma gamma-glutamyltransferase).

RESULTS

Treating all dropouts as relapse to baseline, topiramate was more efficacious than placebo at reducing the percentage of heavy drinking days from baseline to week 14 (mean difference, 8.44%; 95% confidence interval, 3.07%-13.80%; P = .002). Prespecified mixed-model analysis also showed that topiramate compared with placebo decreased the percentage of heavy drinking days (mean difference, 16.19%; 95% confidence interval, 10.79%-21.60%; P < .001) and all other drinking outcomes (P < .001 for all comparisons). Adverse events that were more common with topiramate vs placebo, respectively, included paresthesia (50.8% vs 10.6%), taste perversion (23.0% vs 4.8%), anorexia (19.7% vs 6.9%), and difficulty with concentration (14.8% vs 3.2%).

CONCLUSION

Topiramate is a promising treatment for alcohol dependence.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00210925.

Efficacy and safety of topiramate for the treatment of chronic migraine: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To evaluate the efficacy and safety of topiramate (100 mg/day) compared with placebo for the treatment of chronic migraine.

METHODS

This was a randomized, placebo-controlled, parallel-group, multicenter study consisting of 16 weeks of double-blind treatment. Subjects aged 18 to 65 years with 15 or more headache days per month, at least half of which were migraine/migrainous headaches, were randomized 1:1 to either topiramate 100 mg/day or placebo. An initial dose of topiramate 25 mg/day (or placebo) was titrated upward in weekly increments of 25 mg/day to a maximum of 100 mg/day (or to the maximum tolerated dose). Concomitant preventive migraine treatment was not allowed, and acute headache medication use was not to exceed 4 days per week during the double-blind maintenance period. The primary efficacy endpoint was the change from baseline in the mean monthly number of migraine/migrainous days; the change in the mean monthly number of migraine days also was analyzed. A fixed sequence approach (ie, gatekeeper approach) using analysis of covariance was used to analyze the efficacy endpoints. Assessments of safety and tolerability included physical and neurologic examinations, clinical laboratory parameters, and spontaneous reports of clinical adverse events.

RESULTS

The intent-to-treat population included 306 (topiramate, n = 153; placebo, n = 153) of 328 randomized subjects who provided at least 1 efficacy assessment; 55.8% of the topiramate group and 55.2% on placebo were trial completers. The mean final topiramate maintenance dose was 86.0 mg/day. The mean duration of therapy was 91.7 days for the topiramate group and 90.6 days for the placebo group. Topiramate treatment resulted in a statistically significant mean reduction of migraine/migrainous headache days (topiramate -6.4 vs placebo -4.7, P= .010) and migraine headache days relative to baseline (topiramate -5.6 vs placebo -4.1, P= .032). Treatment-emergent adverse events occurred in 132 (82.5%) and 113 (70.2%) of topiramate-treated and placebo-treated subjects, respectively, and were generally of mild or moderate severity. Most commonly reported adverse events in the topiramate group were paresthesia (n = 46, 28.8%), upper respiratory tract infection (n = 22, 13.8%), and fatigue (n = 19, 11.9%). The most common adverse events in the placebo group were upper respiratory tract infection (n = 20, 12.4%), fatigue (n = 16, 9.9%), and nausea (n = 13, 8.1%). Discontinuations due to adverse events occurred in 18 (10.9%) topiramate subjects and 10 (6.1%) placebo subjects. There were no serious adverse events or deaths.

CONCLUSIONS

Topiramate treatment at daily doses of approximately 100 mg resulted in statistically significant improvements compared with placebo in mean monthly migraine/migrainous and migraine headache days. Topiramate is safe and generally well tolerated in this group of subjects with chronic migraine, a burdensome condition with important unmet treatment needs. Safety and tolerability of topiramate were consistent with experience in previous clinical trials involving the drug.

Efficacy and tolerability of the new antiepileptic drugs I: treatment of new onset epilepsy: report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society

OBJECTIVE

To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs (AEDs) (gabapentin, lamotrigine, topiramate, tiagabine, oxcarbazepine, levetiracetam, and zonisamide-reviewed in the order in which these agents received approval by the US Food and Drug Administration) in the treatment of children and adults with newly diagnosed partial and generalized epilepsies.

METHODS

A 23-member committee, including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy, evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane library for relevant articles from 1987 until September 2002, with selected manual searches up until 2003.

RESULTS

There is evidence either from comparative or dose-controlled trials that gabapentin, lamotrigine, topiramate, and oxcarbazepine have efficacy as monotherapy in newly diagnosed adolescents and adults with either partial or mixed seizure disorders. There is also evidence that lamotrigine is effective for newly diagnosed absence seizures in children. Evidence for effectiveness of the new AEDs in newly diagnosed patients with other generalized epilepsy syndromes is lacking.

CONCLUSIONS

The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with newly diagnosed epilepsy and identify those seizure types and syndromes where more evidence is necessary.

Efficacy and tolerability of the new antiepileptic drugs II: Treatment of refractory epilepsy: Report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society

OBJECTIVE

To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs (AEDs) (gabapentin, lamotrigine, topiramate, tiagabine, oxcarbazepine, levetiracetam, and zonisamide) in the treatment of children and adults with refractory partial and generalized epilepsies.

METHODS

A 23-member committee including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane library for relevant articles from 1987 until March 2003.

RESULTS

All of the new AEDs were found to be appropriate for adjunctive treatment of refractory partial seizures in adults. Gabapentin can be effective for the treatment of mixed seizure disorders, and gabapentin, lamotrigine, oxcarbazepine, and topiramate for the treatment of refractory partial seizures in children. Limited evidence suggests that lamotrigine and topiramate are also effective for adjunctive treatment of idiopathic generalized epilepsy in adults and children, as well as treatment of the Lennox Gastaut syndrome.

CONCLUSIONS

The choice of AED depends upon seizure and/or syndrome type, patient age, concomitant medications, AED tolerability, safety, and efficacy. The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with refractory epilepsy and identify those seizure types and syndromes where more evidence is necessary.

Pharmacological treatment of alcohol dependence: target symptoms and target mechanisms

Alcoholism is a major public health problem and resembles, in many ways, other chronic relapsing medical conditions. At least 2 separate dimensions of its symptomatology offer targetable pathophysiological mechanisms. Systems that mediate positive reinforcement by alcohol are likely important targets in early stages of the disease, particularly in genetically susceptible individuals. In contrast, long term neuroadaptive changes caused by chronic alcohol use primarily appear to affect systems mediating negative affective states, and gain importance following a prolonged history of dependence. Feasibility of pharmacological treatment in alcoholism has been demonstrated by a first wave of drugs which consists of 3 currently approved medications, the aldehyde dehydrogenase blocker disulfiram, the opioid antagonist naltrexone (NTX) and the functional glutamate antagonist acamprosate (ACM). The treatment toolkit is likely to be expanded in the near future. This will improve overall efficacy and allow individualized treatment, ultimately taking in account the patient's genetic makeup. In a second wave, early human efficacy data are available for the 5HT3 antagonist ondansetron, the GABA-B agonist baclofen and the anticonvulsant topiramate. The third wave is comprised of compounds predicted to be effective based on a battery of animal models. Using such models, a short list of additional targets has accumulated sufficient preclinical validation to merit clinical development. These include the cannabinoid CB1 receptor, receptors modulating glutamatergic transmission (mGluR2, 3 and 5), and receptors for stress-related neuropeptides corticotropin releasing factor (CRF), neuropeptide Y (NPY) and nociceptin. Once novel treatments are developed, the field faces a major challenge to assure their delivery to patients.

Topiramate enhances GABA-mediated chloride flux and GABA-evoked chloride currents in murine brain neurons and increases seizure threshold

The anticonvulsant topiramate is effective in laboratory animals against maximal electroshock seizures, amygdala kindling, and spike-wave discharges and has demonstrated efficacy in humans for the treatment of complex partial seizures. However, its mechanism of action has yet to be clearly elucidated. When the chloride-sensitive fluorescent probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE) was used as a tool for estimating the effect of anticonvulsant drugs on GABA receptor function, topiramate was observed to enhance GABA-stimulated chloride (Cl-) flux. At a therapeutic concentration, topiramate (10 microM) enhanced GABA-stimulated (10 microM) Cl- influx into cerebellar granule neurons but did not significantly increase Cl- influx alone. Phenytoin (10 microM) and acetazolamide (300 microM) did not enhance GABA-stimulated Cl- influx. In patch-clamp electrophysiological studies, topiramate also enhanced GABA-evoked whole cell Cl- currents in mouse cerebral cortical neurons in culture. In vivo anticonvulsant studies confirmed that topiramate, like phenytoin, is primarily effective against tonic extension seizures induced by maximal electroshock and is ineffective against clonic seizures induced by the subcutaneously administered chemoconvulsants pentylenetetrazol (PTZ), bicuculline (Bic), and picrotoxin (Pic). In contrast to phenytoin, topiramate, at a dose equivalent to the MES median effective dose (ED50), was found to elevate seizure threshold as estimated by the intravenous PTZ seizure threshold test. Taken together these results support the conclusion that enhancement of GABA-mediated Cl- flux may represent one mechanism that contributes to the anticonvulsant activity of topiramate.

Topiramate placebo-controlled dose-ranging trial in refractory partial epilepsy using 200-, 400-, and 600-mg daily dosages. Topiramate YD Study Group

We conducted a randomized double-blind comparison of three doses of the novel antiepileptic drug (AED) topiramate (200, 400, and 600 mg/day) and placebo as adjunctive therapy in patients with refractory partial onset epilepsy receiving one or two other AEDs at therapeutic concentrations. A total of 181 patients completed the 12-week baseline phase and were randomized to double-blind therapy. Median percent reductions from baseline in average monthly seizure rate, the principal efficacy evaluation, were 13% for placebo, 30% for topiramate 200 mg/day, 48% for topiramate 400 mg/day, and 45% for topiramate 600 mg/day. For the seizure rate comparison of active drug to placebo p values were: topiramate 200 mg/day, p = 0.051; topiramate 400 mg/day, p = 0.007; topiramate 600 mg/day, p < 0.001. Percent responders ( > or = 50% reduction in seizure rates) were 18% for placebo, 27% for topiramate 200 mg/day, 47% for topiramate 400 mg/day (p = 0.013), and 46% for topiramate 600 mg/day (p = 0.027). A significant (p = 0.003) reduction in secondarily generalized seizures compared with placebo treatment was also documented with topiramate. Topiramate plasma concentrations were closely related to dosage, and there were no significant interactions between topiramate and other AEDs. The minimal effective dose of topiramate in this study population was approximately 200 mg/day. Mild or moderate CNS symptoms were the primary treatment-emergent adverse events, but treatment-limiting adverse events occurred in only 9% of patients given topiramate compared with 7% given placebo. Results of this initial well-controlled study in patients indicate that topiramate is a very promising new AED.

The new antiepileptic drugs: a systematic review of their efficacy and tolerability

PURPOSE

Gabapentin (GBP), lamotrigine (LTG), tiagabine (TGB), topiramate (TPM), vigabatrin (VGB), and zonisamide (ZNS) are all in use as "add-on" treatment for patients with refractory epilepsy. There have been no comparative randomized controlled trials allowing an evidence-based choice between these drugs. We report a series of meta-analyses of randomized placebo-controlled add-on trials in which these drugs have been tested in patients with partial epilepsy. This work provides an estimate of each drug's efficacy and tolerability compared with placebo. These estimates are compared across drugs to give broad estimates of comparative efficacy and tolerability.

METHODS

Trial reports were found by searching Medline, by searching through journals by hand, and by contacting the pharmaceutical industry. The outcomes chosen were the proportion of patients who (a) have a > or = 50% reduction in seizure frequency (50% responders); (b) withdrew from the study (any reason); or (c) reported the following side effects: ataxia, dizziness, fatigue, nausea, or somnolence. Overall odds ratio (OR) with 95% confidence intervals (CIs; 50% responders) or 99% CIs; side effects) were calculated.

RESULTS

Twenty-nine trials were included, representing 4,091 randomized patients. The ORs for 50% response (95% CI) were GBP, 2.29 (1.53-3.43); LTG, 2.32 (1.47-3.68); TGB, 3.03 (2.01-4.58); TPM, 4.07 (2.87-5.78); VGB, 3.67 (2.44-5.51); and ZNS, 2.7 (1.36-4.47). ORs for discontinuation were GBP, 1.36 (0.75-2.49); LTG, 1.19 (0.79-1.79); TGB, 1.81 (1.21-2.70); TPM, 2.56 (1.64-4.00); VGB, 2.58 (126-5.27); and ZNS, 4.23 (1.71-10.49).

CONCLUSIONS

We have clear evidence that each of these drugs is better than placebo at preventing seizures. When results are compared across drugs, the confidence intervals overlap, and we have no conclusive evidence of differences in efficacy or tolerability. Despite this, the agent that appears most effective may be twice as effective as the agent that appears least effective, and the agent that appears most likely to cause discontinuation may be 4 times more likely to do so than the treatment that appears least likely to do so. Comparative randomized studies are needed further to evaluate these drugs.

Topiramate in the treatment of binge eating disorder associated with obesity: a randomized, placebo-controlled trial

OBJECTIVE

Binge eating disorder is associated with obesity. Topiramate is an antiepileptic agent associated with weight loss. The objective of this study was to evaluate topiramate in the treatment of binge eating disorder associated with obesity.

METHOD

For this 14-week, double-blind, flexible-dose (25-600 mg/day) topiramate trial, 61 outpatients (53 women, eight men) with binge eating disorder who were obese (body mass index >/=30 kg/m(2)) were randomly assigned to receive topiramate (N=30) or placebo (N=31). The primary efficacy measure was binge frequency. The primary analysis of efficacy was a repeated-measures random regression with treatment-by-time as the effect measure.

RESULTS

Compared with placebo, topiramate was associated with a significantly greater rate of reduction in binge frequency, binge day frequency, body mass index, weight, and scores on the Clinical Global Impression severity scale and the Yale-Brown Obsessive Compulsive Scale (modified for binge eating). Topiramate was also associated with significantly greater reductions in binge frequency (topiramate: 94%, placebo: 46%) and binge day frequency (topiramate: 93%, placebo: 46%) and with a significantly higher level of response than placebo. The mean weight loss for topiramate-treated subjects who completed the study was 5.9 kg. Median topiramate dose was 212 mg/day (range=50-600). Nine patients (three receiving placebo, six given topiramate) discontinued because of adverse events. The most common reasons for discontinuing topiramate were headache (N=3) and paresthesias (N=2).

CONCLUSIONS

Topiramate was efficacious and relatively well tolerated in the short-term treatment of binge eating disorder associated with obesity.

A double-blind, randomized trial of topiramate in Lennox-Gastaut syndrome. Topiramate YL Study Group

OBJECTIVE

To evaluate the efficacy and safety of topiramate as adjunctive therapy for Lennox-Gastaut syndrome in a multicenter, double-blind, placebo-controlled trial.

BACKGROUND

Conventional antiepileptic drugs are frequently ineffective against multiple-seizure types of Lennox-Gastaut syndrome.

METHODS

Ninety-eight patients >1 year to <30 years of age, with slow spike-and-wave patterns on EEG, seizure types including drop attacks, and either a history of or active atypical absence seizures, were assigned to an 11-week, double-blind treatment phase with either topiramate or placebo. Topiramate was titrated to target doses of approximately 6 mg/kg/d.

RESULTS

For drop attacks, the most severe seizures associated with this syndrome, the median percentage reduction from baseline in average monthly seizure rate was 14.8% for the topiramate group and -5.1% (an increase) for the placebo group (p = 0.041). Topiramate-treated patients demonstrated greater improvement in seizure severity than did placebo-treated patients based on parental global evaluations (p = 0.037). The percentage of patients with a > or = 50% reduction from baseline in major seizures (drop attacks and tonic-clonic seizures) was greater in the topiramate group (15/46 or 33%) than in the control group (4/50 or 8%; p = 0.002). The most common adverse events in both groups were CNS related; there were no discontinuations from topiramate therapy due to adverse events.

CONCLUSIONS

Topiramate adjunctive therapy was effective in reducing the number of drop attacks and major motor seizures and in improving seizure severity as determined by parental global evaluation.

Trial of Amitriptyline, Topiramate, and Placebo for Pediatric Migraine

BACKGROUND

Which medication, if any, to use to prevent the headache of pediatric migraine has not been established.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of amitriptyline (1 mg per kilogram of body weight per day), topiramate (2 mg per kilogram per day), and placebo in children and adolescents 8 to 17 years of age with migraine. Patients were randomly assigned in a 2:2:1 ratio to receive one of the medications or placebo. The primary outcome was a relative reduction of 50% or more in the number of headache days in the comparison of the 28-day baseline period with the last 28 days of a 24-week trial. Secondary outcomes were headache-related disability, headache days, number of trial completers, and serious adverse events that emerged during treatment.

RESULTS

A total of 361 patients underwent randomization, and 328 were included in the primary efficacy analysis (132 in the amitriptyline group, 130 in the topiramate group, and 66 in the placebo group). The trial was concluded early for futility after a planned interim analysis. There were no significant between-group differences in the primary outcome, which occurred in 52% of the patients in the amitriptyline group, 55% of those in the topiramate group, and 61% of those in the placebo group (amitriptyline vs. placebo, P=0.26; topiramate vs. placebo, P=0.48; amitriptyline vs. topiramate, P=0.49). There were also no significant between-group differences in headache-related disability, headache days, or the percentage of patients who completed the 24-week treatment period. Patients who received amitriptyline or topiramate had higher rates of several adverse events than those receiving placebo, including fatigue (30% vs. 14%) and dry mouth (25% vs. 12%) in the amitriptyline group and paresthesia (31% vs. 8%) and weight loss (8% vs. 0%) in the topiramate group. Three patients in the amitriptyline group had serious adverse events of altered mood, and one patient in the topiramate group had a suicide attempt.

CONCLUSIONS

There were no significant differences in reduction in headache frequency or headache-related disability in childhood and adolescent migraine with amitriptyline, topiramate, or placebo over a period of 24 weeks. The active drugs were associated with higher rates of adverse events. (Funded by the National Institutes of Health; CHAMP ClinicalTrials.gov number, NCT01581281 ).

A 6-month randomized, placebo-controlled, dose-ranging trial of topiramate for weight loss in obesity

OBJECTIVE

To evaluate the efficacy and safety of topiramate (TPM) for weight loss in healthy obese subjects.

RESEARCH METHODS AND PROCEDURES

A randomized, double-blind, placebo-controlled, dose-ranging trial was conducted. Three hundred eighty-five subjects, 18 and 75 years of age, were randomized to receive either placebo or TPM at 64, 96, 192, or 384 mg daily. Dosing began at 16 mg once daily. In week 2, the dose was increased to 16 mg twice daily. Thereafter, the dose was raised every week by 32 mg/d (16 mg twice daily) until subjects reached their target dose. Twenty-four weeks after beginning treatment, all subjects were tapered off treatment by a dose reduction of 50% per week. All participants received the same lifestyle program.

RESULTS

Mean percent weight loss from baseline to week 24 was -2.6% in placebo-treated patients vs. -5.0%, -4.8%, -6.3%, and -6.3% in the 64, 96, 192, and 384 mg/d TPM groups, respectively. Greater percentages of TPM-treated patients lost at least 5% or 10% of body weight compared with placebo. The most frequent adverse events were related to the central or peripheral nervous system, including paresthesia, somnolence, and difficulty with memory, concentration, and attention. Most events were dose-related, occurred early in treatment, and usually resolved spontaneously; only 21% receiving TPM withdrew due to adverse events compared with 11% on placebo.

DISCUSSION

TPM produced significantly greater weight loss than placebo at all doses.

A pilot trial of topiramate for the treatment of cocaine dependence

BACKGROUND

Both GABAergic and glutamatergic neurons appear to be important modulators of the brain reward system and medications that affect GABA and glutamatergic neurotransmission may reduce the rewarding properties of cocaine and reduce cocaine craving. Topiramate, an anticonvulsant, raises cerebral GABA levels, facilitates GABAergic neurotransmission and inhibits glutametergic activity at AMPA/kainite receptors. Thus, it may be useful for treating cocaine dependence.

METHODS

The efficacy of topiramate for cocaine dependence was tested in a 13-week, double-blind, placebo-controlled pilot trial (n = 40). Topiramate was titrated gradually over 8 weeks to a dose of 200 mg daily. The primary outcome measure was cocaine abstinence verified by twice weekly urine benzoylecgonine tests (UBT).

RESULTS

Eighty-two percent of subjects completed the trial. Analysis of the UBT using a GEE model showed that after week 8, when the dose titration was completed, topiramate-treated subjects were more likely to be abstinent from cocaine compared to placebo-treated subjects (Z = 2.67, P = 0.01). Topiramate-treated subjects were also more likely to attain 3 weeks of continuous abstinence from cocaine (chi2 = 3.9, d.f. = 1, P = 0.05).

CONCLUSION

Topiramate may be effective for the treatment of cocaine dependence.

Assessment of interrater and intrarater reliability of the Fahn-Tolosa-Marin Tremor Rating Scale in essential tremor

The purpose of this study was to evaluate interrater and intrarater reliability of the Fahn-Tolosa-Marin Tremor Rating Scale (TRS) in essential tremor (ET). Proper treatment of ET is contingent upon correct assessment of the severity, loss of function, and disability related to tremor. Videotape recordings of 17 subjects with ET evaluated with the TRS were produced and sent to 59 raters. Once the raters returned the videotape and completed the score sheet, they were mailed a second tape with the same recordings presented in a different order. In the interrater reliability evaluation, modified Kappa statistics for seven tremor type composites ranged from 0.10 to 0.65 in the first videotape and 0.17 to 0.62 in the second videotape. Interrater reliabilities were greater for Part A items (magnitude of tremor in different body parts) than for Part B items (tremor in writing and drawings) of the TRS. The average Spearman correlation was 0.87, indicating very good consistency between the two videotapes, but correlations for Part A were somewhat better than for Part B. It is best when the same rater performs repeated measures of tremor on a patient, particularly when judging tremor in handwriting and drawings. Training of raters on use of the TRS would help standardize judgement.

Glutamate receptor-mediated oligodendrocyte toxicity in periventricular leukomalacia: a protective role for topiramate

Periventricular leukomalacia is a form of hypoxic-ischemic cerebral white matter injury seen most commonly in premature infants and is the major antecedent of cerebral palsy. Glutamate receptor-mediated excitotoxicity is a predominant mechanism of hypoxic-ischemic injury to developing cerebral white matter. We have demonstrated previously the protective effect of AMPA-kainate-type glutamate receptor blockade in a rodent model of periventricular leukomalacia. The present study explores the therapeutic potential of glutamate receptor blockade for hypoxic-ischemic white matter injury. We demonstrate that AMPA receptors are expressed on developing human oligodendrocytes that populate fetal white matter at 23-32 weeks gestation, the period of highest risk for periventricular leukomalacia. We show that the clinically available anticonvulsant topiramate, when administered post-insult in vivo, is protective against selective hypoxic-ischemic white matter injury and decreases the subsequent neuromotor deficits. We further demonstrate that topiramate attenuates AMPA-kainate receptor-mediated cell death and calcium influx, as well as kainate-evoked currents in developing oligodendrocytes, similar to the AMPA-kainate receptor antagonist 6-nitro-7-sulfamoylbenzo-(f)quinoxaline-2,3-dione (NBQX). Notably, protective doses of NBQX and topiramate do not affect normal maturation and proliferation of oligodendrocytes either in vivo or in vitro. Taken together, these results suggest that AMPA-kainate receptor blockade may have potential for translation as a therapeutic strategy for periventricular leukomalacia and that the mechanism of protective efficacy of topiramate is caused at least in part by attenuation of excitotoxic injury to premyelinating oligodendrocytes in developing white matter.

A randomized, placebo-controlled study of topiramate in primary generalized tonic-clonic seizures. Topiramate YTC Study Group

BACKGROUND AND OBJECTIVE

Topiramate is effective as adjunctive treatment of partial-onset seizures in adults. The efficacy and safety of topiramate as adjunctive therapy for the treatment of primary generalized tonic-clonic (PGTC) seizures were investigated in a randomized, double-blind, placebo-controlled study.

METHODS

Eighty patients, 3 to 59 years old, who experienced three or more PGTC seizures during an 8-week baseline phase were randomly assigned to treatment with either topiramate (n = 39) or placebo (n = 41). Topiramate was titrated to target doses of approximately 6 mg/kg/day over 8 weeks and maintained for another 12 weeks.

RESULTS

The median percentage reduction from baseline in PGTC seizure rate was 56.7% for topiramate patients and 9.0% for placebo patients (p = 0.019). The proportion of patients with 50% or higher reduction in PGTC seizure rate was 22/39 (56%) and 8/40 (20%) for the topiramate and placebo groups, respectively (p = 0.001). The median percentage reduction in the rate of all generalized seizures was 42.1% for topiramate patients and 0.9% for placebo patients (p = 0.003). The proportions of patients with 50% or higher reductions in generalized seizure rate were 18/39 (46%) and 7/41 (17%) for the topiramate and placebo groups, respectively (p = 0.003). The most common adverse events were somnolence, fatigue, weight loss, difficulty with memory, and nervousness. Treatment-limiting adverse events occurred in one patient in the topiramate group (anorexia and weight loss) and one in the placebo group (granulocytopenia and thrombocytopenia).

CONCLUSION

Topiramate is well-tolerated and effective for the adjunctive treatment of PGTC seizures.

The new antiepileptic drugs: scientific review

CONTEXT

The past decade has brought many advances to the treatment of epilepsy, including many new pharmacological agents. Primary care physicians often care for patients with epilepsy and therefore should be familiar with the new options available.

OBJECTIVE

To review data regarding the efficacy and tolerability of antiepileptic drugs introduced in the past decade.

DATA SOURCES

A search of the Cochrane Central Register of Controlled Trials was performed to identify all published human and English-language randomized controlled trials evaluating the efficacy and tolerability of the antiepileptic drugs that have been approved for use in the United States since 1990. Additional reports evaluating pharmacokinetic properties were identified through a MEDLINE search as well as review of article bibliographies.

STUDY SELECTION AND DATA EXTRACTION

Search terms included felbamate, gabapentin, lamotrigine, topiramate, tiagabine, levetiracetam, oxcarbazepine, and zonisamide. Studies were selected if efficacy and tolerability were reported as major outcome measures. Included studies (n = 55) enrolled a minimum of 20 adult subjects and had a treatment period of at least 6 weeks.

DATA SYNTHESIS

Eight new antiepileptic drugs have been approved for use in the United States in the past decade. Each new antiepileptic drug is well tolerated and demonstrates statistically significant reductions in seizure frequency over baseline. No randomized controlled trials have compared the new antiepileptic drugs with each other or against the traditional antiepileptic drugs. Although there is no evidence to suggest that the newer medications are more efficacious, several studies have demonstrated broader spectrum of activity, fewer drug interactions, and overall better tolerability of the new agents.

CONCLUSIONS

New antiepileptic drugs offer many options in the treatment of epilepsy, each with unique mechanisms of action as well as adverse effect profiles. The new antiepileptic drugs are well tolerated with few adverse effects, minimal drug interactions, and a broad spectrum of activity.

Review of the use of topiramate for treatment of bipolar disorders

Lithium alone or in combination with other psychotherapeutic drugs has long been the gold standard of management for bipolar disorder (BD). Recognition of its limitations in the acute and chronic management of BD has led to the development of alternative therapies. One such approach involves the use of antiepileptic drugs (AEDs). The AED topiramate is currently being studied in the efficacy and management of BD. Topiramate has mechanisms in common with other AEDs, including sodium channel-blocking activity and enhancement of cerebral GABA concentrations. Open-label trials have evaluated topiramate at mean daily doses of 100 to 300 mg in various BD subtypes, including acute mania, depression, rapid-cycling, mixed states, and BD refractory to other medications. Results from these trials suggest topiramate may be efficacious in BD subtypes, particularly in rapid-cycling patients and those refractory to conventional treatment. Its side effect profile appears benign when used as monotherapy or in combination with other mood stabilizers. Placebo-controlled, double-blind studies are warranted to evaluate topiramate further in BD.