Topiramate 100 mg/day in migraine prevention: a pooled analysis of double-blind randomised controlled trials

Topiramate has been shown to be effective as a preventive treatment for migraine in three large placebo-controlled, dose-ranging trials. Because the protocols were similar in design using the same primary and secondary endpoints, data from these studies were pooled to evaluate the consistency of efficacy, efficacy by gender and tolerability of topiramate 100 mg/day (n = 386) versus placebo (n = 372). Topiramate was superior to placebo as measured by the reduction in mean monthly migraine frequency, monthly migraine days and monthly migraine duration. The responder rates, defined as at least 50% reduction for the respective parameters, were significantly in favour of topiramate (p < 0.001), for example 46.3% of patients on topiramate achieved at least 50% reduction in monthly migraine period frequency compared with 22.8% on placebo (p < 0.001). Use of medication to treat the acute migraine attack was significantly reduced by topiramate compared with placebo (p < 0.001). The therapeutic effect was consistent throughout the different studies and independent of gender. The most common adverse effect was paraesthesia, mostly of mild-to-moderate severity. The findings confirm that, at a dose of 100 mg/day, topiramate is an effective and well-tolerated drug for migraine prevention.     

Topiramate for migraine prevention in children: a randomized, double-blind, placebo-controlled trial

OBJECTIVE: To assess the efficacy and safety of topiramate for the prevention of pediatric migraine with or without aura in a double-blind, randomized, placebo-controlled trial. BACKGROUND: Treatment options for pediatric migraine are currently limited, and no migraine preventive agents are approved for use in children in the United States. Topiramate is an effective migraine preventive therapy in adults, as demonstrated in several large, randomized, placebo-controlled trials. METHODS: One hundred and sixty-two children with migraine (age, 6 to 15 years) were randomized in a 2:1 ratio to receive topiramate (n = 112) or placebo (n = 50). This study was designed to ensure that 150 participants were randomized to study medication. An additional 12 qualified patients were randomized because they had successfully completed the screening phase. The double-blind phase of the trial consisted of a titration period and a maintenance period. Topiramate was initiated at 15 mg/day and titrated over 8 weeks to 2 to 3 mg/kg per day, or maximum tolerated dose, whichever was less (maximum allowed dose was 200 mg/day). The target dose was maintained for 12 weeks. The primary efficacy variable was the change in mean number of migraine days per month (28 days) during the double-blind phase relative to the 4-week prospective baseline phase for each treatment group. RESULTS: Topiramate treatment was associated with a mean reduction over the entire double-blind phase of 2.6 migraine days per month, compared with a mean reduction of 2.0 migraine days per month for placebo (P = .061 topiramate vs. placebo). A significantly greater percentage of topiramate patients (32%) experienced a > or = 75% reduction in mean monthly migraine days compared with placebo (14%, P = .02). Discontinuation rates due to adverse events were low: 6.5% for the topiramate group and 4.0% for the placebo group. The adverse events that occurred most commonly in the topiramate group at an incidence rate greater than in the placebo group were: upper respiratory tract infection, anorexia, weight decrease, gastroenteritis, paresthesia, and somnolence. The mean average daily dose of topiramate during the maintenance period was 2.0 mg/kg per day. CONCLUSIONS: This pilot study suggests that topiramate may be an effective migraine preventive therapy in children. Topiramate was well tolerated in this population. Further randomized studies would be required to definitively establish the efficacy of topiramate for pediatric migraine prevention.     

Topiramate for migraine prophylaxis among Chinese population

We evaluated the efficacy and safety of topiramate for migraine prophylaxis among Chinese patients in a multicenter prospective observational study. We found that topiramate at low doses was effective in preventing migraine headache in Chinese patients and was generally well tolerated. There was no difference in baseline headache frequency or intensity between responders and nonresponders.     

Topiramate as an adjunctive treatment in migraine prophylaxis

BACKGROUND: Anticonvulsants now are commonly used for headache prevention. Topiramate, one of the newer anticonvulsants, recently has been demonstrated to be effective as monotherapy for migraine prophylaxis. OBJECTIVE: To assess the efficacy, safety, and tolerability of topiramate as adjunctive prophylactic therapy for migraine. MATERIAL AND METHODS: A prospective trial involving patients with more than 3 migraine attacks per month was performed. Patients continued their usual prophylactic treatment. Baseline analgesic use and frequency and duration of migraine attacks were recorded. A 4-point visual analog scale evaluated severity. Laboratory tests, electrocardiogram, and computed tomography or magnetic resonance imaging were performed before study entry. After informed consent was obtained, patients were instructed to take 25 mg of topiramate per day, with 25- to 50-mg weekly increments to a maximum of 100 mg per day. Safety was assessed at the first month; tolerability and efficacy were assessed every week for the first month and then every month for 3 months. Effectiveness was assessed by comparing baseline and on-treatment migraine status, and data were analyzed by the Fisher exact test. RESULTS: Twenty-five women and 11 men (mean age, 44 years) were evaluated. Existing prophylactic treatment was either propranolol or flunarizine (or both) in 80% of the patients. At 3 months of therapy with topiramate, headache frequency decreased from 17 to 3 episodes per month, headache duration from 559 to 32 minutes, and intensity from 9 to 1 by visual analog scale (P <.001). Improvement in frequency and severity of migraine was observed in 83% of patients. Slight or no changes in headache were observed in 6 patients. Tolerability was good in 30 patients. The most common side effects were acroparesthesias, weight loss, sleepiness, and headache worsening. No adverse interaction with propranolol or flunarizine was observed. CONCLUSIONS: These results suggest that topiramate is efficacious and safe as an adjunctive treatment in patients with migraine whose prior response to prophylactic management has been less than satisfactory.     

Topiramate prophylaxis and response to triptan treatment for acute migraine

OBJECTIVE: To evaluate the effect of topiramate migraine prophylaxis on subject responsiveness to triptans used for acute symptomatic migraine treatment. BACKGROUND: Clinical experience suggests that prophylactic migraine treatment may enhance the efficacy of symptomatic medications used to treat acute migraine attacks. METHODS: This open-label, single-arm multicenter study consisted of a 6-week baseline period followed by a 16-week topiramate treatment period. Subjects meeting International Headache Society (IHS) criteria for migraine with and without aura signed consent and entered the baseline period. Those with 3 to 12 migraine periods per month during baseline received topiramate prophylactic treatment. Only patients who completed at least 12 weeks of topiramate treatment were included in the data analysis. RESULTS: Of 55 patients screened, 40 subjects entered the topiramate treatment period and 21 subjects received at least 12 weeks of treatment. Mean final dose of topiramate was 124 mg per day (range 50 to 200 mg per day). During the baseline period, the mean percentage of attacks rendered pain-free at 2 hours for the 21 subjects was 46.9% (SD = 31.9), while during the topiramate treatment period it was 44.6% (SD = 32.2) (P= .8). On topiramate, after the first 8 weeks of dosage titration, patients experienced a mean of 3.68 migraine attacks/month, compared to 4.31 during the baseline period (P < .03). Thirteen subjects discontinued because of adverse events. The most commonly reported adverse events were paresthesia, fatigue, anxiety, and dizziness. CONCLUSION: Although topiramate prophylaxis did reduce migraine attack frequency, in this pilot study topiramate prophylactic migraine treatment did not increase the proportion of patients pain-free 2 hours after symptomatic triptan therapy.     

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.     

Topiramate vs divalproex sodium in the preventive treatment of migraine: a prospective "real-world" study

(Headache 2011;51:554‐558) Background and objectives.— Certain neuromodulators, most notably topiramate (TPM) and divalproex sodium (DVP), are effective preventive agents for migraine. Published data from head‐to‐head studies comparing TPM and DVP are not available. The purpose of this study was to compare TPM and DVP for the prophyaxis of migraine in a “real‐world” setting. Methods.— At 2 centers and over a period of 12 months we prospectively evaluated and treated a consecutive series of migraine patients. At baseline all were experiencing less than 15 headache days/month, and we treated all patients requiring prophylactic therapy with either TPM or DVP. We evaluated adherence, headache frequency (HF) and tolerability after 3 months of treatment. TPM treatment was initiated at 25 mg daily and increased every 10 days (25 mg) to a target of 150 mg/day (2 divided doses/day). Treatment with DVP was initiated at 250 mg daily and sequentially titrated up to 500 mg twice daily. All patients were naïve to the use of TPM and DVP. Results.— One hundred and twenty patients (104 women and 16 men of ages 18 to 68, mean 41.2 years) were included. Topiramate selectively was prescribed to 69 patients and DVP selectively to 51. Baseline HF for both groups was similar (8 ± 4 headache days/month). By intention to treat analysis at 3 months, 40 (58%) of patients initially treated with TPM and 26 (51%) of those initially treated with DVP experienced a reduction in HF of >50% (P = NS). Ten patients (14.5%) initially treated with TPM and 8 (15.7%) initially treated with DVP did not return for follow up or were begun on alternative prophylactic therapy. The most common side effects manifested by TPM patients were weight loss (50% of those who completed the treatment period), paresthesia (48%), and cognitive disturbances (20%), whereas DVP patients who completed the treatment period reported weight gain, hair loss, and gastrointestinal symptoms (approximately 24% for each). The mean doses achieved by those completing the study were 140 mg/day for TPM and 890 mg/day for DVP. Conclusions.— Although any conclusions from this investigation necessarily are limited because of our study's open‐label nonrandomized design, these results suggest that TPM and DVP are reasonably effective and generally well tolerated when used to treat a “real‐world” population of episodic migraineurs who require prophylaxis.     

Comparison of the effect of topiramate and sodium valporate in migraine prevention: a randomized blinded crossover study

BACKGROUND: Topiramate and sodium valporate are anticonvulsants, demonstrated to be effective as monotherapy for migraine prevention in placebo-controlled trials. OBJECTIVES: To compare the relative efficacy of topiramate and sodium valporate in the prevention of migraine. PATIENTS AND METHODS: A 24-week, randomized, double-blind, crossover, clinical trial was conducted from October 2003 to September 2004. A total of 64 patients with migraine headache, aged 14 to 57 years, were randomly allocated to the 2 treatment groups. The first group received topiramate (25 mg daily increment over 1 week to 50 mg) for a total of 2 months. The second group received sodium valporate (200 mg daily increment over 1 week to 400 mg) for 2 months. Response to treatment was assessed at 0, 1, 8, 16, and 24 weeks after start of therapy. RESULTS: Topiramate appeared to be equivalent in efficacy and safety to sodium valporate. A significant decrease in duration, monthly frequency, and intensity of headache occurred in both groups. Of the 32 patients treated with sodium valporate, the mean standard deviation (SD) of monthly migraine frequency decreased from 5.4 (2.5) to 4.0 (2.8) episode per month, headache intensity from 7.7 (1.2) to 5.8 (1.7) by visual analog scale (VAS), and headache duration from 21.3 (14.6) to 12.3 (10.7) hours (P < .001). Correspondingly, in the 32 patients treated with topiramate, the mean SD of monthly headache frequency decreased from 5.4 (2.0) to 3.2 (1.9) per month, headache intensity from 6.9 (1.2) to 3.7 (1.3), and headache duration from 17.3 (8.4) to 3.9 (2.7) hours (P < .001). CONCLUSION: This study demonstrates that treatment with topiramate and sodium valporate both significantly reduce migraine headache. This effect of topiramate and sodium valporate has previously been shown to reduce migraine headache, and we postulate that treatment with topiramate and sodium valporate may have a similar benefit.     

Practical Use of Topiramate for Migraine Prevention

When treating patients with migraine, clinicians should consider prescribing appropriate combinations of acute and preventive therapies. An effective migraine-preventive therapy should be prescribed to patients with frequent (≥2 migraines per month) or severe migraine. Topiramate has been shown to be an effective and generally well-tolerated migraine prophylaxis (preventive) therapy in adults, as demonstrated in several large, controlled trials. The most common adverse events in these trials were paresthesia, fatigue, anorexia, nausea, taste alteration, and diarrhea. Most adverse events were mild to moderate and transient in nature. Although patients should take migraine-preventive medications for approximately 2 to 3 months before evaluating effect, topiramate has shown efficacy as early as the first month of treatment. This article describes "real-world" approaches to using topiramate as a migraine-preventive therapy. Topiramate has received regulatory approval for the prophylaxis of migraine headache in adults in the United States and many other countries. The practical issues discussed in this article will enable clinicians to maximize the effectiveness while minimizing the side effects associated with this preventive agent.     

Topiramate: a case series study in migraine prophylaxis

We reviewed the electronic records of 74 migraine patients treated with topiramate for more than 6 weeks. Twenty-four patients had episodic migraine and 50 had chronic (transformed) migraine. Most (81%) started treatment at 25 mg per day and reached a dose of 100 mg twice a day (mean dose on the last follow-up visit was 208 mg). The mean headache frequency decreased from 20.6 days to 13.6 days per month (P<0.0001) for all headaches (9.9-5.1 (P<0.0001) and 25.7-17.7 (P<0.001) for episodic migraine and chronic migraine, respectively). The percentage of patients whose headache frequency was reduced by > or =50% was 44.6% for all patients; 58.3 for episodic migraine and 38.0 for chronic migraine. For all patients mean headache severity (10-point scale) was reduced from 6.2 to 4.8 (P<0.0001). Patients on monotherapy (20%) and polytherapy (80%) had similar reductions in headache frequency. Adverse events were usually mild to moderate and were seen in 58.1% (paresthesias in 25%, cognitive difficulties 14.9%). Mean weight loss was 3.1 +/- 4 kg (3.8% of total body weight).     

Topiramate in the treatment of chronic migraine

The purpose of this study was to evaluate the efficacy of topiramate in the treatment of chronic migraine. This was a double-blind, randomized, placebo controlled, parallel-group study. Patients suffering from chronic migraine with analgesic overuse were randomly assigned in a 1 : 1 ratio to receive topiramate or placebo. Following a baseline phase of eight weeks, the study drug was titrated in 25-mg increments over one week to 50 mg daily. Titration phase was followed by a 8-week maintenance phase. Number of days with headache during a 28-day period was the efficacy variable. At baseline, there was no difference in the number of days with headache between patients treated with topiramate and those treated with placebo (mean +/- SD: 20.9 +/- 3.2 and 20.8 +/- 3.2, respectively). During the last 4 week-maintenance phase, topiramate-treated patients experienced a significantly lower 28-day headache frequency in comparison to those treated with placebo (mean number of days with headache +/- SD: 8.1 +/- 8.1 vs. 20.6 +/- 3.4, P < 0.0007). Topiramate at low doses proved to be an effective therapeutic approach to reduce headache frequency in patients with chronic migraine and analgesic overuse.     

Long-term migraine prevention with topiramate: open-label extension of pivotal trials

OBJECTIVE: To demonstrate that topiramate is an effective and generally well-tolerated migraine preventive therapy when used for up to 14 months. BACKGROUND: Topiramate 100 and 200 mg/d significantly reduced mean monthly migraine frequency during 2 large, 26-week, randomized, placebo-controlled trials. Only a small number of clinical trials have examined the long-term (> or =1 year) effectiveness and safety of migraine preventive therapies. METHODS: Five hundred sixty-seven patients with an established history of migraine with or without aura were enrolled in this 8-month, open-label extension of 2 large (49 US and 52 US and Canadian medical centers), randomized, double-blind, placebo-controlled, parallel group, 26-week trials of identical design. To be eligible for the open-label extension, patients were required to have either completed the double-blind phase of the 2 pivotal migraine prevention trials or withdrew after 4 weeks due to lack of efficacy. All eligible patients, regardless of type or dose of study medication (topiramate or placebo) received in the double-blind phase, were titrated to a clinically effective dose of open-label topiramate based on physician judgment of patient response. Efficacy of topiramate was measured as the change in mean monthly migraine frequency. RESULTS: The mean topiramate dose during the open-label extension phase was 124.7 mg/d and 150.3 mg/d for patients on placebo (n = 159) or topiramate (n = 408), respectively, during the double-blind phase (N = 567, 91% female, mean age 39.4 years). Patients on topiramate for up to 14 months had 2.2 +/- 2.4 (mean +/- SD) migraines per month after completion of the open-label extension phase (3.4 +/- 2.6 at double-blind endpoint). Patients on topiramate during the open-label extension phase only (placebo during the double-blind phase) had 3.0 +/- 2.9 migraines per month at open-label extension endpoint (4.9 +/- 3.0 migraines per month at double-blind endpoint). Discontinuation rates due to adverse events during the double-blind phase were 22.2% for patients on topiramate and 11.0% for patients on placebo. Discontinuation rates due to adverse events during the open-label extension phase were 8.6% for those patients who had already received topiramate during the double-blind phase and 20.9% for those patients who had previously received placebo. CONCLUSIONS: Patients receiving topiramate experienced a sustained reduction in migraine frequency for up to 14 months. The effectiveness and safety of topiramate was consistent with that observed during 2 26-week pivotal trials.     

Topiramate in Migraine Prevention

The efficacy of topiramate in migraine prevention (prophylaxis) was established in two multicenter, randomized, double-blind, placebo-controlled, pivotal trials. Topiramate has received regulatory approval for use in adults for migraine prophylaxis (prevention) in the US and numerous other countries, including France, Ireland, Switzerland, Brazil, Taiwan, Spain, and Australia. Treatment with 100 or 200 mg per day of topiramate was associated with significant reductions in the frequency of migraine headaches, number of migraine days, and use of acute medications. No increase in efficacy was observed between 100 and 200 mg per day of topiramate. Based on efficacy and tolerability, 100 mg per day of topiramate should be the initial target dose for most patients. The most common adverse events were paresthesia, fatigue, decreased appetite, nausea, diarrhea, weight decrease, and taste perversion. Topiramate is a first-line migraine preventive drug and should especially be considered as a preferred treatment for all patients who are concerned about gaining weight, who are currently overweight, or who have coexisting epilepsy.     

Topiramate in patients with episodic migraine: reducing the risk for chronic forms of headache

OBJECTIVE: The aim was to evaluate whether preventive treatment with topiramate in patients with episodic migraine reduces the risk of developing chronic forms of headache. BACKGROUND: Chronic forms of headache, including chronic migraine or medication overuse headache (MOH), are characterized by 15 or more headache days per month. Acute medication overuse has been shown to be a risk factor for developing chronic headache, but it is not known whether preventive treatment can reduce the risk of developing chronic forms of headache or the development of MOH. METHODS: Pooled data from 3 trials in patients with episodic migraine randomized either to treatment with 100 mg topiramate per day (n = 384) or with placebo (n = 372) were analyzed with regard to the number of headache days during a prospective 4-week baseline period and the individual final 4 weeks of each patient's treatment during the planned 26-week double-blind treatment period. RESULTS: The number of headache days per month in the topiramate versus the placebo-treated groups was 7.3 +/- 3.0 versus 7.3 +/- 3.1 during baseline and 4.1 +/- 4.2 versus 5.6 +/- 4.9 during the final 4 weeks, respectively (P < .001). At the end of the study, 8 versus 16 patients fulfilled International Headache Society criteria of chronic headache (odds ratio: 2.11, P= .082). Moreover, a significantly lower number of patients receiving topiramate treatment reported an increase in headache days per month by the end of the study when compared to placebo (66 vs 88 patients, respectively; odds ratio: 1.49, P < .05). Finally, the number of days with usage of acute medication was significantly lower in the topiramate arm compared with placebo (3.3 +/- 3.7 vs 4.3 +/- 3.6, respectively; P < .001). CONCLUSION: Preventive treatment with topiramate in patients with episodic migraine may reduce the risk of developing chronic forms of headache.     

Topiramate improves health-related quality of life when used to prevent migraine

OBJECTIVE: To assess changes in health-related quality of life (HRQoL) measures among patients receiving topiramate (TPM) 100 mg/d in two divided doses for migraine prevention in three randomized, double-blind, placebo-controlled, 26-week trials with similar protocols and study populations. BACKGROUND: Migraine substantially impairs HRQoL and work productivity before, during, and after attacks. Approximately 50% of patients with migraine could be recommended for preventive therapies, yet only 3% to 5% of patients receive them. TPM is an effective and generally well-tolerated migraine prophylactic (preventive) therapy for adults, as demonstrated in several randomized, double-blind, placebo-controlled trials. The most common adverse events in double-blind, placebo-controlled studies of TPM in migraine prevention are paresthesia, fatigue, anorexia, nausea, taste alteration, and diarrhea. DESIGN AND METHODS: The Migraine-Specific Questionnaire (MSQ, version 2.1) was used to assess the effect of TPM 100 mg/d on the functionality and HRQoL of randomized intent-to-treat (ITT) and study-completer populations pooled from three randomized, double-blind, placebo-controlled trials. MSQ scores (0 to 100, higher score indicates better functioning) were assessed for the following three domains: role restriction (examines the degree to which performance of daily activities is limited by migraine), role prevention (examines the degree to which performance of daily activities is interrupted by migraine), and emotional function (examines feelings of frustration and helplessness due to migraine). Between-group differences from baseline in mean MSQ domain scores for TPM 100 mg/d and placebo were compared using a mixed-effects model with piecewise linear regression. Effect sizes were calculated to estimate the magnitude of change in HRQoL that can be associated with TPM therapy. RESULTS: TPM 100 mg/d significantly improved all three MSQ domains compared with placebo for both the ITT (TPM, n = 372; placebo, n = 362) and study-completer (TPM, n = 220; placebo, n = 216) populations (P < .001 for all three domains, both populations). Effect sizes for TPM 100 mg/d varied from 0.40 to 0.78, indicating that the changes in MSQ scores for TPM 100 mg/d were moderate and may be clinically significant. CONCLUSION: TPM 100 mg/d has been shown to be effective in the prevention of migraine headache in adults. As the MSQ results from the three randomized, placebo-controlled trials indicate, HRQoL is significantly improved for up to 6 months following initiation of treatment.     

Cost-effectiveness of migraine prevention: the case of topiramate in the UK

The aim of this study was to assess the cost-effectiveness of topiramate vs. no preventive treatment in the UK. Model inputs included baseline migraine frequency, treatment discontinuation and response, preventive and acute medical cost per attack [2005 GBP ( pound)] and gain in health utility. Outcomes included monthly migraines averted, acute and preventive treatment costs and cost per quality-adjusted life year (QALY). Topiramate was associated with 1.8 fewer monthly migraines and a QALY gain of 0.0384. The incremental cost of topiramate vs. no preventive treatment was about 10 UK pounds per migraine averted and 5700 UK pounds per QALY. Results are sensitive to baseline monthly migraine frequency, triptan use rate and the gain in utility. Incorporating savings from reduced work loss (about 36 UK pounds per month) suggests that topiramate would be cost saving compared with no preventive treatment. This analysis suggests that topiramate is a cost-effective treatment for migraine prevention compared with no preventive treatment.     

Topiramate reduces headache days in chronic migraine: a randomized, double-blind, placebo-controlled study

The aim of this study was to evaluate the efficacy and tolerability of topiramate for the prevention of chronic migraine in a randomized, double-blind, placebo-controlled trial. Chronic migraine is a common form of disabling headache presenting in headache subspecialty practice. Preventive treatments are essential for chronic migraine management, although there are few or no controlled empirical trial data on their use in this patient population. Topiramate is approved for the prophylaxis of migraine headache in adults. Patients (18-65 years) who experienced chronic migraine (defined as > or =15 monthly migraine days) for > or =3 months prior to trial entry and had > or =12 migraine days during the 4-week (28-day) baseline phase were randomized to topiramate or placebo for a 16-week, double-blind trial. Topiramate was titrated (25 mg weekly) to a target dose of 100 mg/day, allowing dosing flexibility from 50 to 200 mg/day, according to patient need. Existing migraine preventive treatments, except for antiepileptic drugs, were continued throughout the trial. The primary efficacy measure was the change in number of migraine days from the 28-day baseline phase to the last 28 days of the double-blind phase in the intent-to-treat population, which consisted of all patients who received at least one dose of study medication and had one outcome assessment during the double-blind phase. Health-related quality of life was evaluated with the Migraine Specific Quality of Life Questionnaire (MSQ, Version 2.1), the Headache Impact Test (HIT-6) and the Migraine Disability Assessment (MIDAS) questionnaires, and tolerability was assessed by adverse event (AE) reports and early trial discontinuations. Eighty-two patients were screened. Thirty-two patients in the intent-to-treat population (mean age 46 years; 75% female) received topiramate (mean modal dose +/- SD = 100 +/- 17 mg/day) and 27 patients received placebo. Mean (+/-SD) baseline number of migraine days per 4 weeks was 15.5 +/- 4.6 in the topiramate group and 16.4 +/- 4.4 in the placebo group. Most patients (78%) met the definition for acute medication overuse at baseline. The mean duration of treatment was 100 and 92 days for topiramate- and placebo-treated patients, respectively. Study completion rates for topiramate- and placebo-treated patients were 75% and 52%, respectively. Topiramate significantly reduced the mean number of monthly migraine days (+/-SD) by 3.5 +/- 6.3, compared with placebo (-0.2 +/- 4.7, P < 0.05). No significant intergroup differences were found for MSQ and HIT-6. MIDAS showed improvement with the topiramate treatment group (P = 0.042 vs. placebo). Treatment emergent adverse events were reported by 75% of topiramate-treated patients (37%, placebo). The most common AEs, paraesthesia, nausea, dizziness, dyspepsia, fatigue, anorexia and disturbance in attention, were reported by 53%, 9%, 6%, 6%, 6%, 6% and 6% of topiramate-treated patients, respectively, vs. 7%, 0%, 0%, 0%, 0%, 4% and 4% of placebo-treated patients. This randomized, double-blind, placebo-controlled trial demonstrates that topiramate is effective and reasonably well tolerated when used for the preventive treatment of chronic migraine, even in the presence of medication overuse.     

Molecular Pharmacology of Topiramate: Managing Seizures and Preventing Migraine

Topiramate is a neuromodulatory compound with stabilizing properties that was initially introduced for the management of partial seizures. Topiramate has been demonstrated to modify several receptor-gated and voltage-sensitive ion channels, including voltage-activated Na⁺ and Ca²⁺ channels and non-NMDA receptors. These receptors have been implicated in the pathophysiology of both epilepsy and migraine. The pharmacological mechanisms of action for topiramate that may explain its antiepileptic and migraine preventive activities will be discussed in this review. In addition, the potential relationship between the molecular activities of topiramate and its efficacy in epilepsy and migraine prevention will be emphasized.     

Efficacy of topiramate in migraine aura prophylaxis: preliminary results of 12 patients

OBJECTIVE: To evaluate the efficacy of topiramate in the treatment of migraine aura. Antiepileptic drugs may be useful in migraine prevention through such mechanisms as acting directly on the nociceptive system or by modulating the biochemical phenomena of aura. Topiramate acts directly on N-methyl-d-aspartate and amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainate glutamate receptors and modulates calcium ion channel activity by inhibiting high-voltage-activated L-type calcium ion channels. METHODS: Twelve patients with migraine with aura were enrolled in an open-label study and treated with topiramate for 6 months. The dose of topiramate was increased weekly by 25 mg up to a daily dose of 100 mg after 4 weeks. RESULTS: In all 12 patients after 6 months of treatment, topiramate did not statistically influence aura frequency (P=.317) or duration (P=.480) compared with baseline. Mild to moderate side effects were observed, but they did not interfere with treatment. Consistent with previous observations, migraine frequency as well as headache intensity and duration improved statistically significantly. CONCLUSION: Topiramate is not effective in preventing migraine aura.