Cinnarizine in refractory migraine prophylaxis: efficacy and tolerability. A comparison with sodium valproate

The comparative effectiveness of migraine preventive drugs: a systematic review and network meta-analysis

OBJECTIVE

While there are several trials that support the efficacy of various drugs for migraine prophylaxis against placebo, there is limited evidence addressing the comparative safety and efficacy of these drugs. We conducted a systematic review and network meta-analysis to facilitate comparison between drugs for migraine prophylaxis.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and clinicaltrials.gov from inception to August 13, 2022, for randomized trials of pharmacological treatments for migraine prophylaxis in adults. Reviewers worked independently and in duplicate to screen references, extract data, and assess risk of bias. We performed a frequentist random-effects network meta-analysis and rated the certainty (quality) of evidence as either high, moderate, low, or very low using the GRADE approach.

RESULTS

We identified 74 eligible trials, reporting on 32,990 patients. We found high certainty evidence that monoclonal antibodies acting on the calcitonin gene related peptide or its receptor (CGRP(r)mAbs), gepants, and topiramate increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, compared to placebo. We found moderate certainty evidence that beta-blockers, valproate, and amitriptyline increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, and low certainty evidence that gabapentin may not be different from placebo. We found high certainty evidence that, compared to placebo, valproate and amitriptyline lead to substantial adverse events leading to discontinuation, moderate certainty evidence that topiramate, beta-blockers, and gabapentin increase adverse events leading to discontinuation, and moderate to high certainty evidence that (CGRP(r)mAbs) and gepants do not increase adverse events.

CONCLUSIONS

(CGRP(r)mAbs) have the best safety and efficacy profile of all drugs for migraine prophylaxis, followed closely by gepants.

Advances in pharmacotherapy for the prophylactic treatment of resistant and refractory migraine

INTRODUCTION

Refractory migraine is associated with low quality of life and great socioeconomic burden. Despite high need for effective, tolerable preventive therapies, there has been little research on potential therapeutic options. Monoclonal antibodies (mAbs) against Calcitonin Gene-Related Peptide (CGRP) are the first preventive therapeutic approach for migraine based on the underlying pathophysiology.

AREAS COVERED

Following a brief introduction into the term 'refractory migraine,' the authors reviewavailable treatment options, focusing on current phase III trials of substances acting on the CGRP pathway.

EXPERT OPINION

No uniform definition for refractory migraine is available. The vast majority of proposals recommend treatment failure of 2-4 drug classes as a key diagnostic criterion. Phase III studies on CGRP-(receptor) mAbs demonstrated excellent efficacy and tolerability in patients with chronic and episodic migraine including subjects with multiple unsuccessful conventional therapy attempts. However, more comparator trials showing superiority of mAbs versus oral preventatives, such as the HER-MEs study are needed. In summary, with the CGRP antibodies, a group of drugs has entered the market which will most likely not only significantly improve the quality of life of many individual migraine patients but could also reduce indirect health-care costs associated with migraine by reducing recurrent medical consultations.

Risk of Valproic Acid-Related Tremor: A Systematic Review and Meta-Analysis

Purpose: To evaluate the incidence and risk of tremor in patients treated with valproic aid (VPA) monotherapy.

Methods: We searched the PubMed, Embase, and Cochrane Library databases to gather relevant data on tremor in patients taking VPA and other drugs and performed a meta-analysis using Stata15.1 software.

Results: Twenty-nine randomized controlled trials (RCTs) met the inclusion criteria and were included in the meta-analysis. The overall incidence of tremor in patients receiving VPA therapy was 14% [OR = 0.14, 95% CI (0.10–0.17)]. The pooled estimate risk of tremor showed a significant difference between patients treated with VPA and all other drugs [OR = 5.40, 95% CI (3.22–9.08)], other antiepileptic drugs (AEDs) [OR = 5.78, 95% CI (3.18–10.50)], and other non-AEDs [OR = 4.77, 95% CI (1.55–14.72)]. Both a dose of <1,500 mg/d of VPA [included 500 mg/d: OR = 3.57, 95% CI (1.24–10.26), 500–999 mg/d: OR = 3.99, 95% CI (1.95–8.20), 1,000–1,499 mg/d: OR = 8.82, 95% CI (3.25–23.94)] and a VPA treatment duration of <12 m [included ≤ 3 months: OR = 3.06, 95% CI (1.16–8.09), 3–6 months: OR = 16.98, 95% CI (9.14–31.57), and 6–12 months: OR = 4.15, 95% CI (2.74–6.29)] led to a higher risk of tremor than did other drugs, as did higher doses and longer treatment times.

Conclusion: Compared with other drugs, VPA led to a higher risk of tremor, and the level of risk was associated with the dose and duration of treatment.

Cinnarizine as an alternative recommendation for migraine prophylaxis: a narrative review

INTRODUCTION

Despite the available prophylactic and acute drugs for migraine management, this disabling disorder remains undertreated especially among pediatrics. In this review, the authors aim at assessing the preventive role cinnarizine plays in treating migraine based on previously published studies.

AREAS COVERED

Randomized clinical trials, randomized controlled trials, non-randomized open-label trials, and retrospective studies concerning cinnarizine in migraine prevention in children and adults were reviewed. Especial attention was given to the response rate, migraine characteristics, and tolerability.

EXPERT OPINION

The majority of reviewed trials demonstrated that cinnarizine is comparable to the conventional drugs used in migraine prophylaxis. However, most of the reviewed studies were limited by a non-controlled open-label design. Due to poor planning and possibility of high placebo responses, particularly in children and adolescents, the interpretation of open-label studies' results should be done cautiously. The evidence shows that cinnarizine's effectiveness was more promising in pediatric migraineurs and adults with migraine-associated vertigo such as vestibular migraine. Therefore, while the efficacy of cinnarizine cannot be dismissed, before reaching a definite conclusion on its effectiveness, it is necessary to do further high-quality RCTs among both children and adults.

Cinnarizine and sodium valproate as the preventive agents of pediatric migraine: A randomized double-blind placebo-controlled trial

BACKGROUND

Few migraine preventive agents have been assessed in a pediatric population. We evaluated the safety and efficacy of cinnarizine and sodium valproate for migraine prophylaxis in children and adolescents.

METHODS

We carried out a randomized double-blind placebo-controlled trial in the Children's Medical Center and Sina hospital, Tehran, Iran. Eligible participants were randomly assigned in 1:1:1 ratio via interactive web response system to receive either cinnarizine, sodium valproate, or placebo. The primary endpoints were the mean change in frequency and intensity of migraine attacks from baseline to the last 4 weeks of trial. The secondary endpoint was the efficacy of each drug in the prevention of migraine. The drug was considered effective if it decreased migraine frequency by more than 50% in the double-blind phase compared with the baseline. Safety endpoint was adverse effects that were reported by children or their parents.

RESULTS

A total of 158 children participated. The frequency of migraine attacks significantly reduced compared to baseline in cinnarizine (difference: -8.0; 95% confidence interval (CI): -9.3 to -6.6), sodium valproate (difference: -8.3; 95% confidence interval: -9.3 to -7.2), and placebo (difference: -4.4; 95% confidence interval: -5.4 to -3.4) arms. The decrease was statistically greater in cinnarizine (difference: -3.6; 95% confidence interval: -5.5 to -1.6) and sodium valproate (difference: -3.9; 95% confidence interval: -5.8 to -1.9) arms, compared to placebo group. Children in all groups had significant reduction in intensity of episodes compared to baseline (cinnarizine: -4.6; 95% confidence interval: -5.2 to -4.0; sodium valproate: -4.0; 95% confidence interval: -4.8 to -3.3; placebo: -2.6; 95% confidence interval: -3.4 to -1.8). The decrease was statistically greater in cinnarizine (difference: -2.0; 95% confidence interval: -3.2 to -0.8) and sodium valproate (difference: -1.5; 95% confidence interval: -2.7 to -0.3) arms, compared to the placebo group. Seventy-one percent of individuals in the cinnarizine group, 66% of cases in the sodium valproate group, and 42% of people in the placebo arm reported more than 50% reduction in episodes at the end of the trial. The odds ratio for >50% responder rate was 3.5 (98.3% confidence interval: 1.3 to 9.3) for cinnarizine versus placebo and 2.7 (98.3% confidence interval: 1.0 to 6.9) for sodium valproate versus placebo. Nine individuals reported adverse effects (three in cinnarizine, five in sodium valproate, and one in the placebo group) and one case in the sodium valproate group discontinued the therapy due to severe sedation.

CONCLUSION

Cinnarizine and sodium valproate could be useful in migraine prophylaxis in children and adolescents. Trial registration: IRCT201206306907N4.

Low-dose sodium valproate versus low-dose propranolol in prophylaxis of common migraine headache: A randomized, prospective, parallel, open-label study

CONTEXT:

Migraine is the second most common headache disorder. However, prophylactic therapy remains underutilized.

AIMS:

The objective of the study was to compare the efficacy and safety of low-dose sodium valproate and low-dose propranolol sustained release (SR) in the prophylaxis of common migraine headache.

SETTINGS AND DESIGN:

The study was conducted in a tertiary care teaching institute. It was a randomized, prospective, parallel, open-label, clinical study.

SUBJECTS AND METHODS:

The study included 60 patients with common migraine headaches (≥2 attacks/month) treated for 12 weeks. The patients were randomly divided into two treatment groups treated by sodium valproate 500 mg/day and propranolol SR 40 mg/day, respectively. The primary outcome measures were the percentage of responders (i.e., >50% decrease in mean headache frequency) at the end of 12 weeks and decrease in mean headache frequency (per 4 weeks) at the end of 12 weeks. The patients were assessed at 0, 4, 8, and 12 weeks of the study.

STATISTICAL ANALYSIS USED:

Intention-to-treat analysis was used for all the statistical analysis.

RESULTS:

Fifty-five patients completed the study. At the end of the treatment, both sodium valproate and propranolol caused a significant (P < 0.0001) reduction in frequency, severity, and duration of migraine headache. Propranolol caused significantly greater reduction in the severity of headache (P = 0.0410) than sodium valproate. The percentage of responders was 60% in sodium valproate group and 70% in propranolol group. Drowsiness was the most common adverse effect noted in both the groups.

CONCLUSION:

Both sodium valproate and propranolol significantly reduced frequency, severity, and duration of migraine headache, but propranolol caused significantly greater reduction in the severity of headache compared to sodium valproate. Both the medications were well tolerated and did not result in discontinuation.

Shared Fate of Meningeal Mast Cells and Sensory Neurons in Migraine

Migraine is a primary headache disorder which has complex neurogenic pathophysiological mechanisms still requiring full elucidation. The sensory nerves and meningeal mast cell couplings in the migraine target tissue are very effective interfaces between the central nervous system and the immune system. These couplings fall into three categories: intimacy, cross-talk and a shared fate. Acting as the immediate call-center of the neuroimmune system, mast cells play fundamental roles in migraine pathophysiology. Considerable evidence shows that neuroinflammation in the meninges is the key element resulting in the sensitization of trigeminal nociceptors. The successive events such as neuropeptide release, vasodilation, plasma protein extravasation, and mast cell degranulation that form the basic characteristics of the inflammation are believed to occur in this persistent pain state. In this regard, mast cells and sensory neurons represent both the target and source of the neuropeptides that play autocrine, paracrine, and neuro-endocrine roles during this inflammatory process. This review intends to contribute to a better understanding of the meningeal mast cell and sensory neuron bi-directional interactions from molecular, cellular, functional points of view. Considering the fact that mast cells play a sine qua non role in expanding the opportunities for targeted new migraine therapies, it is of crucial importance to explore these multi-faceted interactions.

A Comparative Effectiveness Meta-Analysis of Drugs for the Prophylaxis of Migraine Headache

OBJECTIVE

To compare the effectiveness and side effects of migraine prophylactic medications.

DESIGN

We performed a network meta-analysis. Data were extracted independently in duplicate and quality was assessed using both the JADAD and Cochrane Risk of Bias instruments. Data were pooled and network meta-analysis performed using random effects models.

DATA SOURCES

PUBMED, EMBASE, Cochrane Trial Registry, bibliography of retrieved articles through 18 May 2014.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included randomized controlled trials of adults with migraine headaches of at least 4 weeks in duration.

RESULTS

Placebo controlled trials included alpha blockers (n = 9), angiotensin converting enzyme inhibitors (n = 3), angiotensin receptor blockers (n = 3), anticonvulsants (n = 32), beta-blockers (n = 39), calcium channel blockers (n = 12), flunarizine (n = 7), serotonin reuptake inhibitors (n = 6), serotonin norepinephrine reuptake inhibitors (n = 1) serotonin agonists (n = 9) and tricyclic antidepressants (n = 11). In addition there were 53 trials comparing different drugs. Drugs with at least 3 trials that were more effective than placebo for episodic migraines included amitriptyline (SMD: -1.2, 95% CI: -1.7 to -0.82), -flunarizine (-1.1 headaches/month (ha/month), 95% CI: -1.6 to -0.67), fluoxetine (SMD: -0.57, 95% CI: -0.97 to -0.17), metoprolol (-0.94 ha/month, 95% CI: -1.4 to -0.46), pizotifen (-0.43 ha/month, 95% CI: -0.6 to -0.21), propranolol (-1.3 ha/month, 95% CI: -2.0 to -0.62), topiramate (-1.1 ha/month, 95% CI: -1.9 to -0.73) and valproate (-1.5 ha/month, 95% CI: -2.1 to -0.8). Several effective drugs with less than 3 trials included: 3 ace inhibitors (enalapril, lisinopril, captopril), two angiotensin receptor blockers (candesartan, telmisartan), two anticonvulsants (lamotrigine, levetiracetam), and several beta-blockers (atenolol, bisoprolol, timolol). Network meta-analysis found amitriptyline to be better than several other medications including candesartan, fluoxetine, propranolol, topiramate and valproate and no different than atenolol, flunarizine, clomipramine or metoprolol.

CONCLUSION

Several drugs good evidence supporting efficacy. There is weak evidence supporting amitriptyline's superiority over some drugs. Selection of prophylactic medication should be tailored according to patient preferences, characteristics and side effect profiles.

Recent advances in delivery systems and therapeutics of cinnarizine: a poorly water soluble drug with absorption window in stomach

Low solubility causing low dissolution in gastrointestinal tract is the major problem for drugs meant for systemic action after oral administration, like cinnarizine. Pharmaceutical products of cinnarizine are commercialized globally as immediate release preparations presenting low absorption with low and erratic bioavailability. Approaches to enhance bioavailability are widely cited in the literature. An attempt has been made to review the bioavailability complications and clinical therapeutics of poorly water soluble drug: cinnarizine. The interest of writing this paper is to summarize the pharmacokinetic limitations of drug with special focus on strategies to improvise bioavailability along with effectiveness of novel dosage forms to circumvent the obstacle. The paper provides insight to the approaches to overcome low and erratic bioavailability of cinnarizine by cyclodextrin complexes and novel dosage forms: self-nanoemulsifying systems and buoyant microparticulates. Nanoformulations need to systematically explored in future, for their new clinical role in prophylaxis of migraine attacks in children. Clinical reports have affirmed the role of cinnarizine in migraine prophylaxis. Research needs to be dedicated to develop dosage forms for efficacious bioavailability and drug directly to brain.

DUPLICATE: Cinnarizine: A Promising Agent for Migraine Prevention You May Never Get the Chance to Use

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.pediatrneurol.2014.07.002. The duplicate article has therefore been removed. The full Elsevier Policy on Article Removal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Cinnarizine for the prophylaxis of migraine associated vertigo: a retrospective study

Objective

To assess the efficacy and safety of cinnarizine for the prophylaxis of migraine associated vertigo in the vestibular migraine and migraine with brainstem aura.

Background

Vestibular migraine and migraine with brainstem aura are two principal clinical syndromes that frequently are associated with vertigo. Since cinnarizine is a well-tolerated calcium channel blocker which has acceptable effect on both vertigo and migraine headache, we carried out this study to evaluate the efficacy and safety of this medication in vestibular migraine and also migraine with brainstem aura associated with vertigo.

Methods

This was a retrospective, single-center, open-label, investigation of the effects of cinnarizine on vestibular migraine and migraine with associated with vertigo. We assessed the change in monthly frequency of vertigo and also frequency, duration and intensity of migraine attacks after one, two and three months of cinnarizine administration.

Results

The mean frequency of vertigo and also the mean frequency, duration and intensity of migraine headaches per month were reduced significantly after three months of cinnarizine therapy (all p < 0.001).

Conclusion

This study suggests that cinnarizine is safe and effective in reducing both headache and vertigo aspects of “migraine plus vertigo” among the patients who suffer from either vestibular migraine or migraine with brainstem aura associated with vertigo.

Cinnarizine versus Topiramate in Prophylaxis of Migraines among Children and Adolescents: A Randomized, Double-Blind Clinical Trial

OBJECTIVE

Migraines, a common health problem in children and adolescents, still do not have an FDA approved preventive treatment for patients under the age of 18 years. This study compares and contrasts the efficacy and safety of cinnarizine and topiramate in preventing pediatric migraines.

MATERIALS & METHODS

In this randomized, double-blind clinical trial 44 migrainous (from 4-15 years of age) were equally allocated to receive cinnarizine or topiramate. The primary efficacy measure was monthly migraine frequency. Secondary efficacy measures were monthly migraine intensity and ≥ 50% responder rate. Efficacy measures were recorded at the baseline and at 4, 8, and 12 weeks of treatment.

RESULTS

During the double-blind phase of the study, monthly migraine frequency and intensity were significantly decreased in both the cinnarizine and topiramate groups when compared to the baseline. However, at the end of the study, the cinnarizine group exhibits a significant decrease from the baseline in the mean monthly migraine intensity when compared to the topiramate group (4.7 vs. 3, respectively; 95% CI = -0.8 to -3.2).

CONCLUSION

No significant difference between cinnarizine and topiramate was found for the prevention of pediatric migraines. Both treatments were well tolerated.

Valproate (valproic acid or sodium valproate or a combination of the two) for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of valproate (valproic acid or sodium valproate or a combination of the two) for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of valproate taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between valproate and comparator (placebo, active control, or valproate in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and, in select cases, risk ratios (RRs); we also calculated numbers needed to treat (NNTs). We calculated MDs for Migraine Disability Assessment (MIDAS) scores. We also summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Ten papers describing 10 unique trials met the inclusion criteria. Analysis of data from two trials (63 participants) showed that sodium valproate reduced headache frequency by approximately four headaches per 28 days as compared to placebo (MD -4.31; 95% confidence interval (CI) -8.32 to -0.30). Data from four trials (542 participants) showed that divalproex sodium (a stable combination of sodium valproate and valproic acid in a 1:1 molar ratio) more than doubled the proportion of responders relative to placebo (RR 2.18; 95% CI 1.28 to 3.72; NNT 4; 95% CI 2 to 11). One study of sodium valproate (34 participants) versus placebo supported the latter findings (RR for responders 2.83; 95% CI 1.27 to 6.31; NNT 3; 95% CI 2 to 9). There was no significant difference in the proportion of responders between sodium valproate versus flunarizine (one trial, 41 participants) or between divalproex sodium versus propranolol (one trial, 32 participants). Pooled analysis of post-treatment mean headache frequencies in two trials (88 participants) demonstrates a slight but significant advantage for topiramate 50 mg over valproate 400 mg (MD -0.90; 95% CI -1.58 to -0.22). For placebo-controlled trials of sodium valproate and divalproex sodium, NNHs for clinically important adverse events ranged from 7 to 14.

AUTHORS' CONCLUSIONS

Valproate is effective in reducing headache frequency and is reasonably well tolerated in adult patients with episodic migraine.

Italian guidelines for primary headaches: 2012 revised version

The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105-190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version.

Efficacy and safety of cinnarizine in the prophylaxis of migraine headaches in children: an open, randomized comparative trial with propranolol

Migraine headaches are common in children. Early diagnosis and appropriate interventions are mandatory to prevent decades of suffering and diminished quality of life. There is need for data regarding the efficacy and safety of prophylactic agents in children with migraine; therefore, we designed a randomized clinical trial to compare the efficacy and safety of cinnarizine with that of a well-known prophylactic agent (propranolol) in the prophylaxis of pediatric migraine headache. A total of 120 patients aged between 6 and 17 years were recruited and 113 patients succeeded in completing all phases of the trial. Of them, 57 patients were given cinnarizine, and propranolol was administered in 56 patients. Reduction in headache frequency was the main response to treatment. Cinnarizine reduced the baseline headache frequency by more than 50% in 74.6% of patients and the mean headache frequency per month was reduced from 11.851 ± 0.739 (mean ± SEM) to 3.358 ± 0.739 (mean ± SEM) attacks per month (P < 0.001). In the propranolol group, more than 50% reduction of the baseline headache frequency was seen in 72.5% of patients and the mean headache frequency per month was reduced from 10.264 ± 0.830 (mean ± SEM) to 2.774 ± 0.830 (mean ± SEM) attacks per month (P < 0.001). No significant difference was seen in 50% reduction of the baseline headache frequency between treatment groups (P = 0.358). No significant adverse effects were reported. In this open study, cinnarizine appeared thus as effective as propranolol and safe for the prophylaxis of migraine in children, but this remains to be confirmed in a double-blind placebo-controlled trial.

Are the current IHS guidelines for migraine drug trials being followed?

In 2000, the Clinical Trials Subcommittee of the International Headache Society (IHS) published the second edition of its guidelines for controlled trials of drugs in migraine. The purpose of this publication was to improve the quality of such trials by increasing the awareness amongst investigators of the methodological issues specific to this particular illness. Until now the adherence to these guidelines has not been systematically assessed. We reviewed all published controlled trials of drugs in migraine from 2002 to 2008. Eligible trials were scored for compliance with the IHS guidelines by using grading scales based on the most essential recommendations of the guidelines. The primary efficacy measure of each trial was also recorded. A total of 145 trials of acute treatment and 52 trials of prophylactic treatment were eligible for review. Of the randomized, double-blind trials, acute trials scored an average of 4.7 out of 7 while prophylactic trials scored an average of 5.6 out of 9 for compliance. Thirty-one percent of acute trials and 72% of prophylactic trials used the recommended primary efficacy measure. Fourteen percent of the reviewed trials were either not randomized or not double-blinded. Adherence to international guidelines like these of IHS is important to ensure that only high-quality trials are performed, and to provide the consensus that is required for meta analyses. The primary efficacy measure for trials of acute treatment should be “pain free” and not “headache relief”. Open-label or non-randomized trials generally have no place in the study of migraine drugs.

Role of antiepileptic drugs as preventive agents for migraine

Migraine is a common neurological disease affecting about 12% of the population in Western Europe and North America, and causing a considerable burden both to migraineurs and to society. Severe, frequent and disabling migraine attacks, as well as those poorly responsive to acute care medication, require preventive treatment, which is often under-utilized. Antiepileptic drugs are used in the prevention of migraine. We performed a literature search of PubMed through June 2008 for controlled trials of antiepileptic drugs in the prevention of migraine. The search identified 70 papers for a full-text review. The majority of these papers referred to valproate and topiramate, and showed that these drugs are effective and well tolerated in migraine prevention and are suitable for first-line clinical use. On the other hand, acetazolamide, lamotrigine, oxcarbazepine and vigabatrin have been shown to be not effective and gabapentin requires further evaluation. For the rest of the antiepileptic drugs, no data from controlled trials are available.