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At least 19 recordsLinked to original sources
PubMed1996

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.

Adolescent↗
PubMed2000

Topiramate for drug-resistant partial epilepsy.

BACKGROUND: The majority of epileptic patients have a good prognosis and their seizures can be well controlled with the use of a single antiepileptic agent, but up to 30% develop refractory epilepsy, especially those with partial seizures. In this review we summarize the current evidence regarding a new antiepileptic drug, topiramate, when used as an add-on treatment for drug-resistant partial epilepsy. OBJECTIVES: To evaluate the efficacy and tolerability of topiramate when used as an add-on treatment in patients with drug resistant partial epilepsy. SEARCH STRATEGY: (a) The Cochrane Library (1999 Issue 1); (b) The controlled trial register of the Cochrane Epilepsy Group; (c) Johnson and Johnson, makers of topiramate; (d) Experts in the field. SELECTION CRITERIA: Randomized placebo controlled add-on trials of topiramate in patients with drug resistant epilepsy. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion and extracted the relevant data. The following outcomes were assessed: (a) 50% or greater reduction in seizure frequency; (b) treatment withdrawal (any reason); (c) side effects. Primary analyses were intention to treat. Summary odds ratios (OR) were estimated for each outcome. Dose response was evaluated in regression models. MAIN RESULTS: Six trials were included representing 743 randomized patients. EFFICACY: Overall OR (95% CIs) for 50% or greater reduction in seizure frequency compared to placebo 4.06 (2.86-5.78). Dose regression analysis shows increasing efficacy with increasing dose, but found no advantage for doses over 400 mg per day. Global effectiveness: treatment withdrawal OR (95% CIs) compared to placebo 2.57 (1.65-4.00). Side effects: OR (99% CIs)compared to placebo, dizziness 1.99 (1.20-3.29); fatigue 2.52 (1. 47-4.32); nausea 2.84 (1.36-5.93); somnolence 2.89 (1.72-4.85) and 'thinking abnormally' 3.71 (2.02-6.80) were significantly associated with topiramate. REVIEWER'S CONCLUSIONS: Topiramate has efficacy as an add-on treatment in patients with drug resistant partial epilepsy. However, trials reviewed were of relatively short duration, and provide no evidence for the long term efficacy of topiramate. Results cannot be extrapolated to monotherapy or patients with other epilepsy types.

Anticonvulsants↗
PubMed1996

Topiramate placebo-controlled dose-ranging trial in refractory partial epilepsy using 600-, 800-, and 1,000-mg daily dosages. Topiramate YE Study Group.

We conducted a multicenter, double-blind, randomized, parallel, placebo-controlled trial in 190 patients to evaluate the safety and efficacy of three dosages of topiramate (600, 800, and 1,000 mg/day) as adjunctive therapy for patients with refractory partial epilepsy. During an 18-week double-blind treatment period, median percent reductions from baseline in average monthly seizure rates were 1% for placebo, 41% for topiramate 600 mg/day and topiramate 800 mg/day, and 38% for topiramate 1,000 mg/day. There was a 50% or greater reduction from baseline in seizure frequency in 9% of patients in the placebo group and in 44% for topiramate 600 mg/day, 40% for topiramate 800 mg/day, and 38% for topiramate 1,000 mg/day. No placebo patients were improved by 75 to 100% in seizure frequency, whereas 20% of the topiramate patients were improved to this degree. All intent-to-treat drug-placebo comparisons including seizure reduction, percent responders, and investigator and patient global evaluations significantly (p < or = 0.02) favored topiramate. Treatment-emergent adverse events consisted mainly of neurologic symptoms commonly observed during antiepileptic drug (AED) therapy. Sixteen percent of patients on topiramate discontinued therapy due to adverse events. Results of this study indicate that topiramate is a highly efficacious and generally well tolerated new AED. When large groups of patients are compared, incremental efficacy in the add-on setting is not observed at topiramate dosages above 600 mg/day; however, higher doses may prove beneficial to individual patients who tolerate them.

Adolescent↗
PubMed1999

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.

Adolescent↗
PubMed1999

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.

Adolescent↗
PubMed1999

A double-blind, randomized trial of topiramate as adjunctive therapy for partial-onset seizures in children. Topiramate YP Study Group.

OBJECTIVE: To evaluate the efficacy and safety of topiramate 6 mg/kg/day in children (age 2 to 16 years) as adjunctive therapy for uncontrolled partial-onset seizures with or without secondarily generalized seizures in a multicenter, randomized, double-blind, placebo-controlled trial. METHODS: Patients with at least six partial-onset seizures during the 8-week baseline phase were treated with either topiramate (n = 41) or placebo (n = 45) for 16 weeks. RESULTS: Topiramate-treated patients had a greater median percent reduction from baseline in average monthly partial-onset seizure rate than placebo-treated patients (33.1% versus 10.5%, p = 0.034), a greater proportion of treatment responders (i.e., patients with a > or = 50% seizure rate reduction; 16 of 41 [39%] versus 9 of 45 [20%], p = 0.080), and patients with a > or = 75% seizure rate reduction (7 of 41 [17%] versus 1 of 45 [2%], p = 0.019), and better parental global evaluations of improvement in seizure severity (p = 0.019). Emotional lability (12% versus 4%), fatigue (15% versus 7%), difficulty with concentration or attention (12% versus 2%), and forgetfulness/impaired memory (7% versus 0%) were more frequent among topiramate-treated than placebo-treated patients. Most treatment-emergent adverse events were mild or moderate in severity. No topiramate-treated patients discontinued the study due to adverse events. CONCLUSIONS: Topiramate was safe and effective in the treatment of partial-onset seizures in children.

Adolescent↗
PubMed2005

Cost-effectiveness of topiramate in migraine prevention: results from a pharmacoeconomic model of topiramate treatment.

OBJECTIVE: Patients whose migraines are frequent, cause disruptions of daily routines, or are unresponsive to acute treatment are primary candidates for preventive migraine therapy. This cost-effectiveness model assesses the clinical and economic impact of topiramate (TPM) therapy versus no preventive treatment for migraine headache in the United States. BACKGROUND: Despite significant progress in treatment options, the economic burden of migraine to patients, employers, health systems, and society is substantial. Treatment strategies for migraine are directed toward managing acute episodes. However, preventive therapy should be used for patients with frequent migraine attacks (>2 per month) or those experiencing attacks that disrupt daily routines. METHODS: Data for the model were obtained from the published literature and pooled results of two randomized, double-blinded, placebo-controlled trials of TPM in migraine prevention. Model inputs included baseline migraine frequency (the base case assumed 6 per month, consistent with the average rate in the TPM trials), treatment discontinuation (including discontinuation due to adverse events), treatment response (ie, > or = 75%, 50% to 75%, and <50% reduction in migraine frequency), cost of preventive therapy (TPM plus physician visits for medication titration), cost of acute treatment per attack (including pharmacy and medical service costs), hours of disability per attack, hourly wage, and quality-of-life (utility) weights. Model outcomes included the number of migraines averted, disability hours, total cost of acute and preventive treatment, and lost wages. Results were expressed as cost per migraine averted and cost per quality-adjusted life years (QALY). All costs were stated as 2002 U.S. dollars. We also conducted sensitivity analyses to assess the robustness of model findings with respect to variation in key parameters. RESULTS: We estimated that the use of TPM would prevent 1.85 migraines per patient and almost 5 hours of disability per month versus no preventive treatment. Resulting savings in cost of acute treatment (dollar 27) and work loss (dollar 51) offset 68% of the expected monthly cost of TPM (dollar 113). The incremental cost per migraine averted was dollar 19, while the incremental cost per QALY was estimated to be dollar 10,888 (dollar 26,191 when indirect costs were excluded from the analysis). Model results were sensitive to baseline migraine rate and gain in health utility from migraine prevention. CONCLUSIONS: Economic savings associated with reduced migraine frequency offset approximately two thirds of the cost of preventive TPM therapy. The cost-effectiveness of TPM depends on utility gains associated with a reduced frequency of migraine headaches, which is the subject of ongoing research. However, results from our model suggest that the use of TPM in prevention of migraine may offer reasonable value for money relative to many well-accepted medical interventions.

Cost-Benefit Analysis↗
PubMed1999

Topiramate in medically intractable partial epilepsies: double-blind placebo-controlled randomized parallel group trial. Korean Topiramate Study Group.

PURPOSE: To evaluate the efficacy and safety of topiramate (TPM) as add-on therapy in medically intractable partial epilepsies. METHODS: We used a multicenter double-blind placebo-controlled randomized parallel-group trial consisting of 12 weeks of baseline phase, 10 weeks of titration phase, and 8 weeks of stabilization phase. The primary efficacy variable was the median seizure frequency reduction rate (MSFRR), and the other efficacy variables included responder rate, seizure-free rate, and global evaluations by the patient and the physician. The patient should have partial epilepsies refractory to the maximally tolerable doses of one to two antiepileptic drugs (AEDs) and should have two or more episodes of clinical seizures every 4 weeks during the baseline phase. The target dose of study drugs was 600 mg/day. The study drugs were started at the initial dose of 50 mg/day and gradually increased to the target dose over a 10-week period. RESULTS: A total of 177 patients was randomized into the TPM group (n = 91) and the placebo (PLC) group (n = 86). Baseline median seizure frequencies were 5.6 episodes/4 weeks in the TPM and the PLC groups. Among those who were randomized, 174 patients (TPM, 89 patients; PLC, 85 patients) were available for the efficacy measurement by intention-to-treat analysis. The MSFRR was 51.3% for TPM and 9.1% for PLC, which was highly in favor of TPM (p = 0.0001). The responder rate was 50.6% for TPM and 12.9% for PLC (p = 0.001). Seven (7.9%) of 89 patients taking TPM became seizure free compared with one (1.2%) of 85 patients taking PLC (p = 0.004). The global evaluation greatly favored TPM (p = 0.001). The incidence of adverse events (AEs) was higher in the TPM (81.3%) than in the PLC (48.9%) group, with central nervous system (CNS)-related AEs being the most frequent. Among individual AEs, anorexia (20.9%) and abdominal pain or discomfort (20.9%) were the most common AEs in the TPM group. AEs precipitated early drop-out in seven (7.6%) patients taking TPM and three (3.5%) patients taking PLC. No serious systemic AEs were observed. CONCLUSIONS: TPM was highly effective and safe as add-on therapy in medically intractable partial epilepsies. Slower titration of TPM might be responsible for the lesser drop-out rate than previous trials, but the incidence of AEs was still high. The AE profile of TPM in Koreans was different from that in whites.

Abdominal Pain↗
PubMed2000

Topiramate in the long-term management of refractory epilepsy. Topiramate YOL Study Group.

PURPOSE: A total of 292 adult patients (mean age, 33 years) with partial and/or generalized seizures previously resistant to antiepileptic drug (AED) therapy (median baseline seizure rate, 12 seizures/month) were treated with open-label topiramate (TPM) in dosages of 100-1,600 mg/day. METHODS: The mean duration of TPM treatment was 413 days (range, 84-804 days), and the mean TPM dosage was 503 mg/day (range, 100-1,600 mg/day; median TPM dosage, 300 mg/day). Seizure reduction was calculated from seizure counts during the last 3 months and last 6 months of TPM therapy compared with baseline. RESULTS: Overall, >50% of patients achieved > or =50% seizure reduction. More important, 11% of patients were seizure-free for > or =3 months at the last visit; 10% of patients were seizure free for > or =6 months at the last visit. This robust therapeutic response was consistent for patients receiving TPM dosages >400 and <400 mg/day. The most commonly reported adverse events were related to the central nervous system. Over the 2.2-year treatment period, 19% of patients discontinued TPM therapy because of inadequate seizure control; 32% discontinued because of adverse events. Findings from this study show that TPM is a useful agent for long-term seizure control, with some patients becoming seizure free for extended periods despite failing previous AED therapy.

Adolescent↗
PubMed2000

Nonfocal generalized tonic-clonic seizures: response during long-term topiramate treatment. Topiramate YTC/YTCE Study Group.

PURPOSE: A total of 131 adults and children (mean age, 27 years; range, 3-59 years) with generalized tonic-clonic seizures (GTCS) of nonfocal origin resistant to other antiepileptic drugs (AEDs) were treated with open-label topiramate (TPM) after completing double-blind placebo-controlled trials. RESULTS: The mean duration of open-label TPM treatment was 387 days (range, 14-909 days); the mean TPM dose was 7 mg/kg/day (range, 1-16 mg/kg/day). At the last study visit, the frequency of GTCS was reduced > or =50% from baseline in 63% of patients and by > or =75% in 44%. Among patients treated > or =6 months, 16% were GTCS free > or =6 months despite a pretreatment seizure frequency of one GTCS/week (median). Treatment with TPM was being continued in 82% of patients (n = 107) at the last visit. During treatment periods of up to 2.5 years, 11 (8%) patients discontinued TPM because of adverse events and seven (5%) because of inadequate seizure control. CONCLUSIONS: TPM therapy was well tolerated, and seizure control was maintained with long-term, open-label therapy in patients with GTCS, leading to prolonged seizure-free intervals in some patients with seizures previously resistant to AED therapy.

Adolescent↗
PubMed2000

Effectiveness, tolerability, and safety of topiramate in children with partial-onset seizures. Topiramate YP Study Group.

PURPOSE: Children with partial-onset seizures, with or without secondary generalization, participating in a double-blind, placebo-controlled trial of topiramate (TPM) as adjunctive therapy were eligible to participate in an open-label, long-term extension study. METHODS: A total of 83 children (mean age, 9 years) continued long-term open-label TPM therapy in which the dosages of TPM and concomitant antiepileptic drugs (AEDs) were adjusted according to clinical response (mean TPM dosage, 9 mg/kg/day). RESULTS: Seizure frequency over the last 3 months of therapy was reduced > or =50% in 57% of children; 14% of children were seizure-free > or =6 months at the last visit. During treatment periods up to 2 1/2 years (mean, 15 months), 6% of children discontinued because of treatment-emergent adverse events; 13% discontinued because of inadequate seizure control. CONCLUSIONS: From these findings, TPM is well tolerated and provides long-term seizure control in children with partial-onset seizures.

Adolescent↗
PubMed2000

Topiramate in Lennox-Gastaut syndrome: open-label treatment of patients completing a randomized controlled trial. Topiramate YL Study Group.

PURPOSE: The response to topiramate (TPM) as long-term adjunctive therapy was evaluated in patients with Lennox-Gastaut syndrome (LGS) in a long-term, open-label extension to a double-blind, placebo-controlled trial. METHODS: In 97 patients with LGS (mean age, 11 years), dosages of TPM and concomitant antiepileptic drugs (AEDs) were adjusted to optimal clinical response (mean TPM dosage, 10 mg/kg/day). RESULTS: For those patients who had completed 6 months of TPM therapy, drop attacks were reduced > or =50% in 55% of patients; 15% of patients had no drop attacks for > or =6 months at the last visit. After treatment up to 3+ years, 71% of patients who started open-label TPM were continuing therapy at the last visit. CONCLUSIONS: During long-term therapy, TPM is effective and well tolerated in controlling the treatment-resistant drop attacks and seizures associated with LGS.

Adolescent↗
PubMed2000

[Topiramate in clinical practice (part 1). Multicentric retrospective analysis of the efficacy of topiramate as add-on therapy according to the topographic form of focal epilepsy].

Randomized, controlled studies of new antiepileptic drugs do not always highlight their best utilization in clinical practice. The authors gathered 361 cases of focal epilepsies treated with topiramate (TPM) as an add-on to other anti epileptic drugs prior to marketing. Among these, only 237 were treated for at least 3 months and analyzed here. These patients were treated by neurologists in a clinical setting, with free choice of associated drugs, titration and final daily doses. Compared with controlled studies, TPM was titrated slowly (mean rate: 43 mg/week, vs 100 to 200), and was given at a lower final dose (346 mg/d, vs 200 to 1000). This analysis confirmed the efficacy of TPM as add-on therapy in focal epilepsies (9.3p.100 totally controlled, 19 p.100 with reduction of seizures=90 p. 100, 52.7 p.100 responders at=50 p.100). It showed that there was a striking response in epilepsies originating from the central areas, which are often drug-resistant (19 p.100 totally controlled, 33.33 p. 100 with reduction of seizures=90 p.100). There were responders in all topographic groups. There was however no specific response according to etiology.

Adolescent↗
PubMed2002

Serum concentrations of topiramate in patients with epilepsy: influence of dose, age, and comedication.

Topiramate is a new antiepileptic drug (AED) approved as add-on therapy. Previous studies have shown that topiramate has only a limited effect on other AEDs, but its own metabolism can be induced by enzyme-inducing drugs. The aim of this study was to investigate the influence of topiramate dose, age, and comedication, especially of carbamazepine, phenytoin, phenobarbital, oxcarbazepine, lamotrigine, and valproic acid (VPA) on topiramate serum concentrations in patients with epilepsy. In total, 480 samples of 344 inpatients who fulfilled the inclusion criteria (e.g., trough concentration, body weight available) were investigated. The topiramate serum concentration in relation to topiramate dose per body weight (level-to-dose ratio) was calculated and compared for patients receiving topiramate monotherapy and for patients receiving topiramate plus one other AED. Analysis of covariance (using age as covariate) showed that comedication had a highly significant influence on the topiramate serum concentrations. Regression analysis including all 480 samples confirmed that in combinations with phenytoin, carbamazepine, phenobarbital, and oxcarbazepine, the topiramate concentrations were significantly lower compared with topiramate monotherapy, whereas VPA and lamotrigine had no significant influence. Moreover, regression analysis indicated that primidone and methsuximide lowered topiramate concentrations, whereas gabapentin, bromide, and sulthiame did not. In addition to comedication, the patient's age was significantly correlated with topiramate clearance. In accordance with the results of previous studies, these results indicated that infants and children had lower topiramate concentrations than adults receiving the same topiramate dose per body weight. Comedication and age should be considered in adjusting topiramate dosage. Determination of topiramate serum concentrations may be useful, especially when enzyme-inducing drugs are withdrawn or added.

Adolescent↗
PubMed2004

Pharmacokinetic interactions of topiramate.

Topiramate is a new antiepileptic drug (AED) that has been approved worldwide (in more than 80 countries) for the treatment of various kinds of epilepsy. It is currently being evaluated for its effect in various neurological and psychiatric disorders. The pharmacokinetics of topiramate are characterised by linear pharmacokinetics over the dose range 100-800 mg, low oral clearance (22-36 mL/min), which, in monotherapy, is predominantly through renal excretion (renal clearance 10-20 mL/min), and a long half-life (19-25 hours), which is reduced when coadministered with inducing AEDs such as phenytoin, phenobarbital and carbamazepine. The absolute bioavailability, or oral availability, of topiramate is 81-95% and is not affected by food. Although topiramate is not extensively metabolised when administered in monotherapy (fraction metabolised approximately 20%), its metabolism is induced during polytherapy with carbamazepine and phenytoin, and, consequently, its fraction metabolised increases. During concomitant treatment with topiramate and carbamazepine or phenytoin, the (oral) clearance of topiramate increases 2-fold and its half-life becomes shorter by approximately 50%, which may require topiramate dosage adjustment when phenytoin or carbamazepine therapy is added or discontinued. From a pharmacokinetic standpoint, topiramate is a unique example of a drug that, because of its major renal elimination component, is not subject to drug interaction due to enzyme inhibition, but nevertheless is susceptible to clinically relevant drug interactions due to induction of its metabolism. Unlike old AEDs such as phenytoin and carbamazepine, topiramate is a mild inducer and, currently, the only interaction observed as a result of induction by topiramate is that with ethinylestradiol. Topiramate only increases the oral clearance of ethinylestradiol in an oral contraceptive at high dosages (>200 mg/day). Because of this dose-dependency, possible interactions between topiramate and oral contraceptives should be assessed according to the topiramate dosage utilised. This paper provides a critical review of the pharmacokinetic interactions of topiramate with old and new AEDs, an oral contraceptive, and the CNS-active drugs lithium, haloperidol, amitriptyline, risperidone, sumatriptan, propranolol and dihydroergotamine. At a daily dosage of 200 mg, topiramate exhibited no or little (with lithium, propranolol and the amitriptyline metabolite nortriptyline) pharmacokinetic interactions with these drugs. The results of many of these drug interaction studies with topiramate have not been published before, and are presented and discussed for the first time in this article.

Anticonvulsants↗
PubMed2005

Effects of topiramate on ethanol and saccharin consumption and preferences in C57BL/6J mice.

BACKGROUND: Topiramate has recently been found to be more effective than placebo as an adjunct treatment for alcohol dependence, but it has not yet been investigated in animal models of ethanol consumption. The current experiment examined the effects of topiramate on ethanol drinking in mice using a continuous access, two-bottle choice procedure. METHOD: C57BL/6J male mice were offered a 10% v/v ethanol solution versus tap water over 4 consecutive days per week. Mice were assigned to topiramate (1-50 mg/kg) or saline groups and received injections before the beginning of the dark phase of the light cycle. Topiramate dose increased over 5 successive weeks (1, 5, 10, 25, and 50 mg/kg). Fluid intake was measured 2, 4, and 23 hr after injection. Body weight and food intake were measured at the time of injection. In a second phase, mice were offered saccharin solutions (0.2 and 2.5% w/v) versus tap water after topiramate (50 mg/kg) or saline injections. RESULTS: Results revealed that high topiramate doses (25 and 50 mg/kg) increased water intake and decreased ethanol preference. Compared with saline controls, topiramate produced dose-dependent, bidirectional effects on ethanol dose, with 25 mg/kg of topiramate increasing ethanol dose at 4 and 23 hr after injection but 50 mg/kg topiramate decreasing ethanol dose at 2 hr after injection. During saccharin exposure, topiramate decreased saccharin preference (for 2.5% w/v saccharin solution) and marginally increased water intake but did not directly alter intake of the saccharin solutions. Topiramate had no effects on body weight or daily food intakes. CONCLUSIONS: Topiramate reduced ethanol preference in C57BL/6J mice, but this effect was primarily attributable to elevated water intake. Topiramate also reduced saccharin preference, likely through marginally significant increases in water intake. Increases in water intake and bidirectional effects of topiramate on ethanol dose complicate conclusions with regard to the effects of topiramate on ethanol reward.

Alcohol Drinking↗
PubMedDate not supplied

Topiramate in migraine prevention: a double-blind, placebo-controlled study.

OBJECTIVE: To evaluate the efficacy of topiramate in the preventative treatment of episodic migraine. BACKGROUND: Topiramate is a broad-spectrum antiepileptic drug effective for treatment of multiple seizure types in adults and children. Antiepileptic agents have demonstrated efficacy in migraine prevention, and open-label experience from our clinic has suggested that topiramate might be effective for this use. We consequently conducted a single-center, double-blind, placebo-controlled trial to evaluate the efficacy and safety of topiramate for the preventative treatment of migraine. METHODS: Forty patients, aged 19 to 62 years (mean, 38.2 years), were randomly assigned in a 1:1 ratio to receive topiramate (n = 19; all women) or placebo (n = 21; 20 women, 1 man). Following a prospective baseline phase of 4 weeks, the study drug dose was titrated weekly in 25-mg increments over 8 weeks to 200 mg per day or to the maximum tolerated dose. The titration phase was followed by an 8-week maintenance phase. RESULTS: During the entire double-blind phase, topiramate-treated patients experienced a significantly lower 28-day migraine frequency (3.31 +/- 1.7 versus 3.83 +/- 2.1; P =.002) compared to placebo, irrespective of use of concomitant migraine prevention medications. The mean 28-day migraine frequency was reduced by 36% in patients receiving topiramate as compared with 14% in patients receiving placebo (P =.004). Twenty-six percent of the patients on topiramate and 9.5% of the patients on placebo achieved a 50% reduction in migraine frequency (P >.05). The mean dose of topiramate was 125 mg per day (range, 25 to 200 mg per day). Topiramate was well tolerated; 2 of 19 topiramate-treated patients discontinued treatment due to adverse events. Adverse effects that occurred more frequently in topiramate-treated patients included paresthesia, weight loss, altered taste, anorexia, and memory impairment. CONCLUSIONS: Preventative therapy with topiramate significantly reduced migraine frequency. Larger multicenter clinical studies may further delineate the role of topiramate in migraine prevention.

Adolescent↗