Are Migraineurs at Increased Risk of Adverse Drug Responses?: A Meta-Analytic Comparison of Topiramate-Related Adverse Drug Reactions in Epilepsy and Migraine

Resistant and refractory migraine: clinical presentation, pathophysiology, and management

Migraine is a leading cause of disability worldwide. A minority of individuals with migraine develop resistant or refractory conditions characterised by ≥ 8 monthly days of debilitating headaches and inadequate response, intolerance, or contraindication to ≥3 or all preventive drug classes, respectively. Resistant and refractory migraine are emerging clinical definitions stemming from better knowledge of the pathophysiology of migraine and from the advent of migraine-specific preventive treatments. Resistant migraine mostly results from drug failures, while refractory migraine has complex and still unknown mechanisms that impair the efficacy of preventive treatments. Individuals with resistant migraine can be treated with migraine-specific preventive drugs. The management of refractory migraine is challenging and often unsuccessful, being based on combinations of different drugs and non-pharmacological treatment. Future research should aim to identify individuals at risk of developing treatment failures, prevent the condition, investigate the mechanisms of refractoriness to treatments, and find effective treatment strategies.

Emerging drugs for the preventive treatment of migraine: a review of CGRP monoclonal antibodies and gepants trials

INTRODUCTION

Migraine is a leading cause of years lived with disability and preventive strategies represent a mainstay to reduce health-related disability and improve quality of life of migraine patients. Until a few years ago, migraine prevention was based on drugs developed for other clinical indications and relocated in the migraine therapeutic armamentarium, characterized by unfavourable tolerability profiles. The advent of monoclonal antibodies against Calcitonin Gene-Related Peptide (CGRP) and gepants, CGRP receptor antagonists, has been a turning point in migraine prevention owing to advantageous efficacy, safety and tolerability profiles.Nevertheless, while in an ideal scenario a drug characterized by significant greater efficacy and tolerability compared to existing therapeutic strategies should be adopted as a first-line treatment, cost-effectiveness analyses available for monoclonal antibodies against CGRP pathway tend to limit their administration to more severe migraine phenotypes.

AREAS COVERED

The present narrative review aim to provide a critical appraisal of phase II and III CGRP-mAbs and gepants trials to analyse their use in clinical practice.

EXPERT OPINION

Despite monoclonal antibodies against CGRP pathway and gepants can be undoubtedly considered top-of-the-range treatments, there are still issues deserving to be addressed in the coming years as the risk of off-target effects as well as their economic sustainability based on the considerable migraine burden.

The sense of stopping migraine prophylaxis

INTRODUCTION

Migraine prophylactic therapy has changed over recent years with the development and approval of monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway. As new therapies emerged, leading headache societies have been providing guidelines on the initiation and escalation of such therapies. However, there is a lack of robust evidence looking at the duration of successful prophylaxis and the effects of therapy discontinuation. In this narrative review we explore both the biological and clinical rationale for prophylactic therapy discontinuation to provide a basis for clinical decision-making.

METHODS

Three different literature search strategies were conducted for this narrative review. These include i) stopping rules in comorbidities of migraine in which overlapping preventives are prescribed, notably depression and epilepsy; ii) stopping rules of oral treatment and botox; iii) stopping rules of antibodies targeting the CGRP (receptor). Keywords were utilized in the following databases: Embase, Medline ALL, Web of Science Core collection, Cochran Central Register of Controlled Trials, and Google Scholar.

DISCUSSION

Reasons to guide decision-making in stopping prophylactic migraine therapies include adverse events, efficacy failure, drug holiday following long-term administration, and patient-specific reasons. Certain guidelines contain both positive and negative stopping rules. Following withdrawal of migraine prophylaxis, migraine burden may return to pre-treatment level, remain unchanged, or lie somewhere in-between. The current suggestion to discontinue CGRP(-receptor) targeted mAbs after 6 to 12 months is based on expert opinion, as opposed to robust scientific evidence. Current guidelines advise the clinician to assess the success of CGRP(-receptor) targeted mAbs after three months. Based on excellent tolerability data and the absence of scientific data, we propose if no other reasons apply, to stop the use of mAbs when the number of migraine days decreases to four or fewer migraine days per month. There is a higher likelihood of developing side effects with oral migraine preventatives, and so we suggest stopping these drugs according to the national guidelines if they are well tolerated.

CONCLUSION

Translational and basic studies are warranted to investigate the long-term effects of a preventive drug after its discontinuation, starting from what is known about the biology of migraine. In addition, observational studies and, eventually, clinical trials focusing on the effect of discontinuation of migraine prophylactic therapies, are essential to substantiate evidence-based recommendations on stopping rules for both oral preventives and CGRP(-receptor) targeted therapies in migraine.

Calcitonin gene-related peptide (CGRP) monoclonal antibodies for migraine

The introduction of calcitonin gene-related peptide monoclonal antibodies represents a step forward in preventive migraine treatment as the first agents to target the underlying pathogenesis of migraine. In trials they act more quickly, have better long-term adherence and appear to be better tolerated than other treatments. Major disadvantages are their high cost and unknown safety in pregnancy and in cardiovascular disease. To mitigate these concerns, they should be used according to guidance produced by professional bodies, with defined starting and stopping criteria. We do not yet know whether they are more effective than standard care; many patients may still be better treated by other means, in particular addressing lifestyle factors and medication-overuse headache.

Antiseizure Medications for the Prophylaxis of Migraine during the Anti- CGRP Drugs Era

Migraine and epilepsy are fundamentally distinct disorders that can frequently coexist in the same patient. These two conditions significantly differ in diagnosis and therapy but share some widely- used preventive treatments. Antiseizure medications (ASMs) are the mainstay of therapy for epilepsy, and about thirty different ASMs are available to date. ASMs are widely prescribed for other neurological and non-neurological conditions, including migraine. However, only topiramate and valproic acid/valproate currently have an indication for migraine prophylaxis supported by high-quality evidence. Although without specifically approved indications and with a low level of evidence or recommendation, several other ASMs are used for migraine prophylaxis. Understanding ASM antimigraine mechanisms, including their ability to affect the pro-migraine calcitonin gene-related peptide (CGRP) signaling pathway and other pathways, may be instrumental in identifying the specific targets of their antimigraine efficacy and may increase awareness of the neurobiological differences between epilepsy and migraine. Several new ASMs are under clinical testing or have been approved for epilepsy in recent years, providing novel potential drugs for migraine prevention to enrich the treatment armamentarium and drugs that inhibit the CGRP pathway.

Treatment of migraine with monoclonal antibodies

INTRODUCTION

: In the few last years, a new family of drugs, anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs), has been developed for migraine therapy. Anti-CGRP mAbs are highly effective, but the current limited experience with their use and their high-cost warrant establishing certain rules of use.

AREAS COVERED

The present review provides an overview of the management of migraine patients, especially those who are undergoing treatment with anti-CGRP mAbs.

EXPERT OPINION

Thanks to new research focused on the pathophysiology of migraine, and the discovery that CGRP plays a key role in its etiopathogenesis, new drugs targeting CGRP have been developed. These drugs have led to a paradigm shift, anticipating new and stimulating possibilities in migraine treatment. While physicians and patients are full of expectation about the advantages of this new family of drugs, there are still obstacles to overcome in order to make the best use of them. It is essential to form multidisciplinary teams that can identify patients who will benefit from these therapies, conducting cost-effective treatments. The follow-up of these therapies in the coming years is paramount due to the lack of experience in the management of these drugs and the peculiarity of disease evolution in migraine patients.

Relationships between migraine and epilepsy: Pathophysiological mechanisms and clinical implications

Migraine and epilepsy are distinct neurological diseases with specific clinical features and underlying pathophysiological mechanisms. However, numerous studies have highlighted the complex and multifaceted relationships between the two conditions. The relationships between headache and epilepsy manifest themselves in different ways. Firstly, the clinical diagnosis of these disorders may be challenging in view of possible overlapping. While post-ictal headache is a frequent condition, ictal epileptic headache is a rare but challenging diagnosis. Both situations raise the question of the pathophysiological mechanism of headache triggered by seizures. Migraine aura and epilepsy can also exhibit overlapping symptoms leading to their misdiagnosis, in particular in the case of visual aura. Secondly, migraine with aura and epilepsy can occur as a co-morbid condition, particularly in familial hemiplegic migraine (FHM). From a pathophysiological perspective, the identification of genetic mutations in FHM has brought significant advances in the understanding of dysfunctions of neuronal networks leading to hyperexcitability. The purpose of this review is to present clinical situations encompassing headache and epilepsy that can be challenging in neurological practice and to discuss the underlying pathophysiological mechanism of such interactions.

Preventive Migraine Treatment

PURPOSE OF REVIEW

This article provides an overview of preventive interventions for migraine, including when to start and how to choose a treatment, pharmacologic options (both older oral treatments and new monoclonal antibodies to calcitonin gene-related peptide [CGRP] or its receptor), nonpharmacologic treatment such as neuromodulation, and preventive treatment of refractory migraine.

RECENT FINDINGS

The migraine preventive treatment landscape has been transformed by the development of monoclonal antibodies targeting CGRP or its receptor. These treatments, which are given subcutaneously or intravenously monthly or quarterly, have high efficacy and were well tolerated in clinical trials. Emerging real-world studies have found higher rates of adverse events than were seen in clinical trials. They are currently recommended for use if two traditional preventive therapies have proven inadequate. Since the commonly cited 2012 American Headache Society/American Academy of Neurology migraine prevention guidelines were released, clinical trials supporting the preventive use of lisinopril, candesartan, and memantine have been published. Neuromodulation devices, including external trigeminal nerve stimulation and single-pulse transcranial magnetic stimulation devices, have modest evidence to support preventive use. The American Headache Society/American Academy of Neurology guidelines for the preventive treatment of migraine are currently being updated. A new class of oral CGRP receptor antagonists (gepants) is being tested for migraine prevention.

SUMMARY

Successful preventive treatment of migraine reduces disease burden and improves quality of life. Many pharmacologic and nonpharmacologic treatment options are available for the prevention of migraine, including newer therapies aimed at the CGRP pathway as well as older treatments with good evidence for efficacy. Multiple treatment trials may be required to find the best preventive for an individual patient.

Experimental Therapeutic Strategies in Epilepsies Using Anti-Seizure Medications

Epilepsies are among the most common neurological problems. The disease burden in patients with epilepsy is significantly high, and epilepsy has a huge negative impact on patients' quality of life with epilepsy and their families. Anti-seizure medications are the mainstay treatment in patients with epilepsy, and around 70% of patients will ultimately control with a combination of at least two appropriately selected anti-seizure medications. However, in one-third of patients, seizures are resistant to drugs, and other measures will be needed. The primary goal in using experimental therapeutic medication strategies in patients with epilepsy is to prevent recurrent seizures and reduce the rate of traumatic events that may occur during seizures. So far, various treatments using medications have been offered for patients with epilepsies, which have been classified according to the type of epilepsy, the effectiveness of the medications, and the adverse effects. Medications such as Levetiracetam, valproic acid, and lamotrigine are at the forefront of these patients' treatment. Epilepsy surgery, neuro-stimulation, and the ketogenic diet are the main measures in patients with medication-resistant epilepsies. In this paper, we will review the therapeutic approach using anti-seizure medications in patients with epilepsy. However, it should be noted that some of these patients still do not respond to existing treatments; therefore, the limited ability of current therapies has fueled research efforts for the development of novel treatment strategies. Thus, it seems that in addition to surgical measures, we should look for more specific agents that have less adverse events and have a greater effect in stopping seizures.

Topiramate-related adverse events: Pattern and signals in the Korea Adverse Event Reporting System, 2010-2017

Despite safety concerns associated with topiramate use, the pattern of adverse events and signal analysis of antiepileptic drugs remain elusive.We aimed to determine patient demographics and characteristics of reported AEs of topiramate and to detect the associated signals by comparing those of other antiepileptics.We used the Korea Institute of Drug Safety & Risk Management-Korea Adverse Event Reporting System Database (KIDS-KD) from 2010 to 2017 to determine patient demographics and characteristics of reported AEs for topiramate and other antiepileptics. The proportional reporting ratio, reporting odds ratio, and information component were used in signal detection. Signals were compared against drug labels in Korea, the UK, the EU, and the US.A total of 1300 adverse events cases of topiramate were reported, and the number of topiramate-adverse event pairs was 1861. For topiramate, the proportion of women of childbearing age (20-39 years) with adverse events was more than double that for other antiepileptics. A majority of the 36 detected signals were of neuropsychiatric disorders such as cognitive disorders, concentration impaired, amnesia, hypoaesthesia. Patients with topiramate-induced adverse events were likely to be young and female. Also, adverse events related to carbonic anhydrase isoenzyme showed specifically great disproportionalities.Rigorous clinical management is needed to ensure proper and safe use of topiramate. Special precautions should be taken when prescribing in women of childbearing age.

A case series of topiramate-induced angle closure crisis – an ophthalmic emergency

Background

Topiramate is a drug commonly used by physicians. However, it has various systemic and ocular adverse effects. Bilateral angle closure crisis is a potentially blinding adverse reaction that is seldom reported in non-ophthalmic journals.

Objective

This article aims to report a case series of topiramate-induced angle closure crisis in the eyes.

Methods and material

Most patients presented to us with blurred vision and high intra-ocular pressure within days of starting topiramate tablet for headache. However, the attack resolved in those who presented early with prompt treatment, which included stopping topiramate.

Conclusions

Physicians prescribing topiramate must be well aware of this potentially blinding adverse effect. Educating the patient about this possible side effect is important. Timely referral and treatment can prevent blindness in these individuals.

May lamotrigine be an alternative to topiramate in the prevention of migraine with aura? Results of a retrospective study

Background

Evidence suggests that lamotrigine could be effective in reducing aura frequency and duration. However, studies comparing lamotrigine to other, first-line prophylactic agents solely involving patients suffering from migraine with aura are still lacking. The aim of this study was to compare the efficacy of lamotrigine and topiramate for the preventive treatment of migraine with aura.

Methods

Fifty-three patients suffering from migraine with aura treated with lamotrigine or topiramate for at least 6 months were included. Pre- and post-treatment clinical data regarding monthly aura frequency and duration, monthly migraine frequency, days of headache and rescue medication used per month were collected.

Results

Responder rates were similar between the two treatment groups at 6-month follow-up. Interestingly, responder rates for aura frequency and duration were higher in the lamotrigine group compared with the topiramate group (88% vs 79% and 73% vs 54%). Moreover, 50% of the lamotrigine-treated patients reported a complete disappearance of migraine aura compared with 37% of topiramate-treated patients. Side effects were more frequent in topiramate group compared with lamotrigine group (p=0.004).

Conclusions

Lamotrigine should be considered in clinical practice for the preventive treatment of migraine with aura especially for patients reporting prolonged aura and who do not respond, have contraindications or discontinue topiramate treatment due to side effects.

Carbonation dysgeusia associated with topiramate

PURPOSE

A case of carbonation dysgeusia associated with the use of topiramate is reported in order to bring awareness to a lesser-known adverse effect of the medication so that providers may be able to more effectively counsel patients and provide potential solutions.

SUMMARY

A 39-year-old Caucasian woman with longstanding epilepsy was initiated on topiramate therapy after experiencing a generalized seizure (she reported not taking any antiepileptic medication for years). Topiramate was started at a dosage of 25 mg by mouth twice daily and after 3 weeks titrated to a dosage of 100 mg by mouth twice daily for maintenance therapy. After initiation of topiramate therapy, the patient began to experience an immediate change in her carbonation perception when drinking carbonated beverages; all carbonated beverages, including seltzer and beer, tasted "flat." The patient remained on topiramate for the subsequent 12 months without her carbonation perception returning to normal but noted that drinking carbonated beverages through straws slightly mitigated the adverse effect. Case assessment using the adverse drug reaction probability scale of Naranjo et al indicated that topiramate was the probable cause of the patient's carbonation taste perversion.

CONCLUSION

A 39-year-old Caucasian woman developed chronic carbonation dysgeusia after initiation of topiramate following a generalized seizure.

Real-life data on the efficacy and safety of erenumab in the Abruzzo region, central Italy

Background

We aimed to assess the efficacy and safety of erenumab, a fully human monoclonal antibody inhibiting the calcitonin gene-related peptide receptor (CGRPr), for the prevention of migraine in a real-life setting.

Main body

We included in our observational study all patients with episodic or chronic migraine treated with erenumab during the year 2019 in the Abruzzo region, central Italy, and with a 6-month follow-up. We included 89 patients; 76 (85.4%) received 6 doses of erenumab, 11 (12.4%) autonomously withdrew the drug due to perceived inefficacy, and 2 (2.2%) due to adverse events. Seventy-eight patients (87.6%) were female, with a mean age of 46.8 ± 11.2 years; 84 (94.4%) had chronic migraine, and 64 (71.9%) medication overuse. All patients had ≥2 prior preventive treatment failures. Fifty-three patients (69.7%) had a 50% decrease in monthly migraine days (MMDs) within the first three doses; 46 (71.9%) of 64 patients withdrew medication overuse. In the 76 patients who completed a 6-dose treatment, erenumab decreased median MMDs from 19 (interquartile range [IQR] 12–27.5) to 4 (IQR 2–9.5; P < 0.001), median monthly days of analgesic use from 10 (IQR 4.5–20) to 2 IQR 0–5; P < 0.001), and median monthly days of triptan use from 5 (IQR 0–15.5) to 1 (IQR 0–4; P < 0.001). We recorded 27 adverse events in 20 (22.5%) patients, the most common being constipation (13.5%). One adverse event, i.e. allergic reaction, led to treatment discontinuation in one patient.

Conclusions

Our real-life data confirm the efficacy and tolerability of erenumab for the prevention of migraine in a difficult-to-treat population of patients with a high prevalence of chronic migraine and medication overuse.

The Efficacy and Safety of Topiramate in the Prevention of Pediatric Migraine: An Update Meta-Analysis

Background: Migraine is the most common acute primary headache in children and adolescents. In 2014, topiramate became the first preventive drug for migraine, approved by the Food and Drug Administration (FDA) for adolescents. This meta-analysis was aimed to evaluate the efficacy and safety of topiramate in the prevention of pediatric migraine. Methods: We searched the PubMed, EMBASE, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI) databases up to June 2019 for eligible randomized controlled trials (RCTs). The primary outcomes were mean migraine days per month, ≥50% reduction rate, and Pediatric Migraine Disability Assessment Scale (PedMIDAS) scores. RevMan5.3 software was performed for statistical analysis. Results: Overall, 5 RCTs recruiting 531 patients (6-17 years of age) were included in the meta-analysis. The target dose of topiramate was 2 mg/kg (the maintenance phase was 12 weeks), 2-3 mg/kg, 50 mg/day, and 100 mg/day (maintaining for 16 weeks), respectively, in the included studies. Our results demonstrate that participants receiving topiramate had a significant advantage in remitting the monthly migraine days than those receiving placebo, with a mean difference (MD) of -0.78 (n = 531; 95% CI, -1.23 to -0.32; Z = 3.37; P = 0.0008). Topiramate could also reduce the mean PedMIDAS scores (n = 238; 95% CI, -16.53 to -0.49; Z = 2.43; P = 0.04). However, there was no significant difference in the percentage of patients experiencing a ≥50% reduction in monthly headache days between topiramate and placebo groups (n = 531; 95% CI, 0.94-1.77; Z = 1.58; P = 0.11). Topiramate was associated with higher rates of side effects such as weight decrease (n = 395; 95% CI, 2.73-22.98; Z = 3.81; P < 0.01) and paresthesia (n = 531; 95% CI, 3.05-13.18; Z = 4.94; P < 0.01). Conclusions: Topiramate can significantly decrease monthly headache days and migraine-related burden in migraine patients <18 years old. However, it failed to increase 50% response rate. Adverse events seem to be more frequent in topiramate-treated children.

Current Status of Antiepileptic Drugs as Preventive Migraine Therapy

BACKGROUND

Antiepileptic drugs (AEDs) are an important class of agents used in the treatment of migraine, a neurological disorder that imparts significant socioeconomic burden. It is important for neurologists to understand the rationale for AEDs in migraine-preventive treatment, as well as each agent's efficacy and tolerability profile, in order to best determine clinical care.

PURPOSE OF THIS REVIEW

This article specifically provides the following: (1) a review of the mechanism of action, efficacy, and tolerability of topiramate and divalproex sodium/sodium valproate, the most widely used AEDs for migraine prevention, (2) a discussion on emerging evidence regarding the efficacy of zonisamide and levetiracetam, and (3) comments on gabapentin, pregabalin, carbamazepine, oxcarbazepine, and lamotrigine, AEDs which have insufficient evidence for use in migraine prevention.

RECENT FINDINGS

The potential role for new extended-release formulations of topiramate in migraine prevention is discussed. There is substantial evidence supporting the use of AEDs in migraine prevention. Specific agents should be chosen based on their efficacy and tolerability profiles. Further studies are needed to determine the efficacy of the newer AEDs, zonisamide and levetiracetam, in migraine prevention and to clarify the role of gabapentinoids in headache management.

Migraine and Tension-Type Headache: Diagnosis and Treatment

Migraine and tension-type headache are highly prevalent. Migraine is associated with significant work- and family-related disability. Migraine is underdiagnosed; it reasonable to err on the side of migraine when choosing between primary headaches. Barriers to appropriate treatment of migraine include lack of access to providers, misdiagnosis, and acute and preventive therapies not being prescribed. Acute, rescue, and preventive treatment options are extensive, and new classes of treatments are either available or in development. This review addresses diagnostic challenges including recognizing migraine with aura. It also summarizes nonpharmacologic, acute, rescue, and preventive treatment options for migraine and treatment of tension-type headache.

Safety and tolerability of calcitonin-gene-related peptide binding monoclonal antibodies for the prevention of episodic migraine - a meta-analysis of randomized controlled trials

AIM

To systematically evaluate the safety and tolerability of calcitonin-gene-related peptide binding monoclonal antibodies from the results of randomized controlled trials.

METHODS

Online databases were searched on calcitonin-gene-related peptide binding monoclonal antibodies for the prevention of episodic migraine. Overall withdrawal, withdrawal due to adverse events, adverse events, serious adverse events and specific adverse events were extracted from the included studies. A meta-analysis was performed with Revman 5.3.0 software.

RESULTS

Ten studies that investigated four drugs (galcanezumab, erenumab, fremanezumab and eptinezumab) with 5817 participants were included in this study. Serious adverse events, overall withdrawals, withdrawal due to adverse events and any adverse events were not significantly associated with monoclonal antibody treatment. Injection site pain and erythema were significantly higher in the calcitonin-gene-related peptide binding monoclonal antibodies treatment group than in the placebo group. The rates of serious adverse events were significantly higher in the galcanezumab 120 mg group. Injection site erythema was associated with galcanezumab 120 mg and 240 mg. Injection site pain and nasopharyngitis were associated with galcanezumab 150 mg and 5 mg, respectively. Overall adverse events were significantly higher with erenumab 70 mg and 140 mg. Treatment-related adverse events were significantly higher with fremanezumab 225 mg/month and 675 mg/quarter.

CONCLUSIONS

This study provides data on the safety and tolerability profiles of calcitonin-gene-related peptide binding monoclonal antibodies and confirms their potential use as preventive treatments for episodic migraine. In addition to the acceptable withdrawal rates, serious adverse events were rare, and the severity of most adverse events was mild to moderate. Injection site reaction may be the major adverse event associated with galcanezumab.

European headache federation guideline on the use of monoclonal antibodies acting on the calcitonin gene related peptide or its receptor for migraine prevention

BACKGROUND AND AIM

Monoclonal antibodies acting on the calcitonin gene-related peptide or on its receptor are new drugs to prevent migraine. Four monoclonal antibodies have been developed: one targeting the calcitonin gene-related peptide receptor (erenumab) and three targeting the calcitonin gene-related peptide (eptinezumab, fremanezumab, and galcanezumab). The aim of this document by the European Headache Federation (EHF) is to provide an evidence-based and expert-based guideline on the use of the monoclonal antibodies acting on the calcitonin gene-related peptide for migraine prevention.

METHODS

The guideline was developed following the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed systematic review and analysis of the literature, assessed the quality of available evidence, and wrote recommendations. Where the GRADE approach was not applicable, expert opinion was provided.

RESULTS

We found low to high quality of evidence to recommend eptinezumab, erenumab, fremanezumab, and galcanezumab in patients with episodic migraine and medium to high quality of evidence to recommend erenumab, fremanezumab, and galcanezumab in patients with chronic migraine. For several clinical questions, there was not enough evidence to provide recommendations using the GRADE approach and recommendations relied on experts' opinion.

CONCLUSION

Monoclonal antibodies acting on the calcitonin gene-related peptide are new drugs which can be recommended for migraine prevention. Real life data will be useful to improve the use of those drugs in clinical practice.

Real-world assessment of treatment with extended-release topiramate (Trokendi XR®) and comparison with previous immediate-release topiramate treatment

AIM

Examine clinical profile of extended-release topiramate (Trokendi XR^®) and compare treatment-emergent adverse events (TEAEs) associated with Trokendi XR versus previous immediate-release topiramate (TPM-IR) treatment.

PATIENTS & METHODS

Pilot retrospective study analyzing data extracted from medical charts of patients ≥6 years of age prescribed Trokendi XR.

RESULTS

Trokendi XR was the most commonly used to prevent migraine. The most common TEAEs recorded during topiramate treatment were cognitive symptoms (word-finding difficulty, attention/concentration difficulty, slowed thinking), paresthesia, gastrointestinal problems and decreased appetite/weight loss. TEAE incidence was significantly (p < 0.001) lower during Trokendi XR versus previous TPM-IR treatment.

CONCLUSION

Trokendi XR use and outcomes in clinical practice were consistent with established profile of topiramate. Results supported the potential for better tolerability of Trokendi XR versus TPM-IR.

Refining the Benefit/Risk Profile of Anti-Epileptic Drugs in Headache Disorders

Anti-epileptic drugs are among the most effective drugs for migraine prophylaxis, and will likely continue to have a role even as new therapies emerge. Topiramate and valproate are effective for the preventive treatment of migraine, and other medications such as gabapentin or lamotrigine may have a role in the treatment of those with allodynia or frequent aura, respectively. Oxcarbazepine, carbamazepine, phenytoin, gabapentin, and others may alleviate pain in trigeminal neuralgia. While many anti-epileptic drugs can be effective in those with migraine or other headaches, most of these agents can potentially cause serious side effects. In particular, valproate, topiramate, carbamazepine, and phenytoin may lead to adverse outcomes for infants of exposed mothers. Valproate should not be given to women of childbearing potential for migraine prevention.

What the pharmacological management of migraine can tell us about the future of migraine patient care

Some of the principles of the pharmacologic management of migraine are echoed in urgent discussions of the future of headache care in the USA and around the world. From adverse events to tolerance, addiction, medication overuse and medication persistence, solutions to the pathophysiologic puzzles, and management difficulties in migraine can be found by paying closer attention to patient reports and by facilitating greater patient involvement in the treatment process. Similarly, listening to the patient as customer in the process of value-based care, so adaptable for the problem of migraine, is the solution to the health care crisis we face in so many countries.

Evaluating the reporting of adverse events in controlled clinical trials conducted in 2010–2015 on migraine drug treatments

Background

In 2008, the International Headache Society published guidelines on the “evaluation and registration of adverse events in clinical drug trials on migraine”. They listed seven recommendations for reporting adverse events in randomized controlled trials on migraine. The present study aimed to evaluate adherence to these recommendations, and based on the results, to recommend improvements.

Methods

We searched the PubMed/MEDLINE database to identify controlled trials on migraine drugs published from 2010 to 2015. For each trial, we noted whether five of the recommended parameters were presented. In addition, we noted whether adverse events were reported in abstracts.

Results

We identified 73 trials; 51 studied acutely administered drugs and 22 studied prophylactic drugs for migraine. The number of patients with any adverse events were reported in 74% of acute-administration and 86% of prophylactic drug trials. Only 30 (41%) of the 73 studies reported adverse events with data in the abstracts, and 27 (37%) abstracts did not mention adverse events.

Conclusion

Adverse events, both frequency and symptoms, should be reported to allow a fair judgement of benefit/tolerability ratio when randomized controlled trials in migraine treatment are published. Clinically significant adverse events should be included in the abstract of every randomized controlled trial in migraine treatment.

Calcitonin gene-related peptide monoclonal antibodies for migraine prevention: comparisons across randomized controlled studies

PURPOSE OF REVIEW

The results of phase 2 randomized controlled trials for the prevention of episodic and chronic migraine demonstrating the efficacy and safety of four mAbs targeting the calcitonin gene-related peptide (CGRP) pathway [ALD403 (eptinezumab), AMG334 (erenumab), LY2951742 (galcanezumab) and TEV48125 (fremanezumab)] have been published recently, and phase 3 trials are in process. This development will change headache management fundamentally. We aim to summarize and compare the phase 2 data.

RECENT FINDINGS

The change from baseline in the number of migraine days at the end of treatment in high-frequency episodic migraine was -1 (at weeks 5-8), -1.1 (at weeks 9-12), -1.2 (at weeks 9-12) and -2.6 (at weeks 9-12) days for ALD403, AMG344, LY2951742 and TEV48125 (225 mg), respectively. Number needed to treats for responders and odds ratio for any adverse event were 4.7, 6.2, 4.0 and 4.0 and 1.09, 0.96, 1.07 and 1.05, respectively.

SUMMARY

All four CGRP antibodies display comparable efficacy that does not differ significantly from that of the currently available oral antimigraine drugs. However, their safety and tolerability profiles as well as low frequency of administration looks promising but remains to be verified in long-term and large-scale trials. Considerations related to pregnancy, risk for cardiovascular effects and cost are subject for further evaluation.

Using a graphical risk tool to examine willingness to take migraine prophylactic medications

Many migraine sufferers use daily prophylactic therapy to reduce the frequency of their headache attacks. The Food and Drug Administration has approved several different medications for migraine prophylaxis, but it is not clear whether sufferers perceive these treatments to provide clinically significant benefits given their side effect profiles. Three hundred headache sufferers were recruited from the community and local headache clinics using print and television advertising. Participants reported experiencing problematic headache attacks with a median (IQR) frequency of 7.0 (4-13) headache days per month. These sufferers participated in a cross-sectional, single-site, study that used a specially designed computer assessment task. Participants were instructed on the probability of experiencing the 3 most commonly experienced side effects for several blinded medication profiles: divalproex sodium, venlafaxine, gabapentin, propranolol, and topiramate. After learning the likelihood of experiencing side effect profiles of each medication, participants were asked whether they would be willing to take the medication for a given headache reduction level, which ranged from 0 to 7 days per month. The side effect profile for divalproex sodium was associated with the smallest willingness to take, with gabapentin, propranolol, and topiramate perceived to be much more agreeable. However, <60% of participants reported willingness to take any of these medications even if they provided a 50% reduction in headache frequency. Several general predictors of willingness to take were observed including high headache-related disability, depressive symptoms, and pain medication concerns including fear of tolerance. These findings suggest that if properly informed of the side effect profiles of these medications, many patients might opt for other treatments.

Calcitonin gene-related peptide monoclonal antibody for preventive treatment of episodic migraine: A meta analysis

Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) have shown promise in the preventive treatment of migraine. Therefore, we performed a meta-analysis to evaluate the efficacy and safety of CGRP mAbs for preventive treatment of migraine. Database including Ovid-SP, Cochrane Library, Pubmed and Web of Science (ISI) were systematically searched up to April 2, 2016 for randomized controlled trials(RCTs) which were dealing with the efficacy and safety of CGRP mAbs for preventive treatment of episodic migraine. Cochrane collaboration's tool for assessing risk of bias was utilized for evaluating the bias and quality of RCTs. The data was analyzed by reviewer manager 5.2. Totally, 4 literatures matched the inclusion criteria, including 4 independent RCTs and 1198 patients. Among mentioned above, AMG334 is a monoclonal antibody against CGRP receptor, but ALD403, LY2951742 and TEV-48125 are monoclonal antibody against CGRP. We found that 7mg and 21mg AMG334 couldn't reduce the monthly migraine days from baseline to week 1-4/9-12. But 70mg AMG334 could reduce the monthly migraine days from baseline to week 9-12 (MD=-1.1, 95% CI=[-2.1,-0.2]; P=0.021) significantly, as compared with placebo. Meanwhile, after pooled estimate the efficacy of CGRP mAb against CGRP, we found that CGRP mAbs improved the decrease of monthly migraine days from baseline to week 1-4, as compared with placebo (WMD=1.62, 95% CI=[1.09,2.14], I²=0%, P<0.00001). And CGRP mAbs improved the decrease of monthly migraine days from baseline to week 9-12, no matter in single dose subgroup (WMD=1.83, 95%CI=[0.06,3.60], I²=69%,P=0.04) or in multiple doses subgroup (WMD=1.77, 95%CI=[0.40,3.14], I²=61%,P=0.01). And there were no difference in incidence of adverse events between CGRP mAb group and placebo group. In conclusion, CGRP mAbs was a safety and effective preventive treatment for episodic migraine.

Antiepileptic drugs in migraine and epilepsy: Who is at increased risk of adverse events?

Background The impact of adverse events (AEs) of antiepileptic drugs (AEDs) have an impact on compliance and dropouts. We compared tolerability of AEs of AEDs among patients with migraine, epilepsy, or both. Methods Overall, 335 patients (epilepsy (n = 142), migraine (n = 131), and both (n = 62)), were evaluated with the Liverpool Adverse Events Profile (LAEP) to assess the magnitude, profile and occurrence rate of the AEs of valproate, topiramate, and lamotrigine. Results AEs were significantly more common with topiramate treatment (71.0%) and among migraineurs (69.5%), the latter being more prone to discontinue AEDs (46.6%). The profile of AEs with topiramate and valproate differed among groups. Moreover, treatment with both topiramate and valproate was associated, for all groups, with a worse tolerability profile compared to lamotrigine. Conclusion Our data suggest a specific drug and disease AE profile of AEDs. Specifically, migraineurs are the most affected by AEs, even though they receive very low dosages of AEDs. This finding might be considered a clinical implication of central sensitization mechanisms. Both the profile and tolerability of AEs, highly influencing quality of life, depended on the underlying conditions, and deeply impacted on treatment dropout. Therefore, before starting, switching or stopping AED treatment, all options need to be considered.

Topiramate in Migraine Prevention: A 2016 Perspective

BACKGROUND

In evidence-based guidelines published in 2000, topiramate was a third-tier migraine preventive with no scientific evidence of efficacy; recommendation for its use reflected consensus opinion and clinical experience. Its neurostabilizing activity, coupled with its favorable weight profile, made topiramate an attractive alternative to other migraine preventives that caused weight gain. When guidelines for migraine prevention in episodic migraine were published in 2012, topiramate was included as a first-line option based on double-blind, randomized controlled trials involving nearly 3000 patients. The scientific and clinical interest in topiramate has generated a large body of data from randomized controlled trials, meta-analyses, patient registries, cohort studies, and claims data analyses that have more fully characterized its role as a migraine preventive.

AIM

This article will review the profile of topiramate that has emerged out of the past decade of research and clinical use in migraine prophylaxis. It will also address the rationale for extended-release (XR) formulations in optimizing topiramate therapy in migraine.

SUMMARY

Topiramate has activity at multiple molecular targets, which may account for why it is effective in migraine and most other, more specific, anticonvulsants are not. Based on randomized controlled trials, topiramate reduces migraine frequency and acute medication use, improves quality of life, and reduces disability in patients with episodic migraine and in those with chronic migraine with or without medication overuse headache. Its efficacy in chronic migraine is not improved by the addition of propranolol. Topiramate's ability to prevent progression from high-frequency episodic migraine to chronic migraine remains unclear. Consistent with clinicians' perceptions, migraineurs are more sensitive to topiramate-associated side effects than patients with epilepsy. Paresthesia is a common occurrence early in treatment but is rarely cause for terminating topiramate treatment. Cognitive problems occur much less frequently than paresthesia but are more troublesome in terms of treatment discontinuation. Cognitive complaints can often be managed by slowly increasing the topiramate dose in small increments to allow habituation. As with other carbonic anhydrase inhibitors, topiramate has metabolic effects that favor the development of metabolic acidosis and possibly renal stones. Because migraineurs have an increased risk of renal stones independent of topiramate exposure, clinicians should counsel all migraine patients to maintain hydration. Abrupt onset of blurring, other visual disturbances, and/or ocular pain following topiramate's initiation should be evaluated promptly since this may indicate rare but potentially sight-threatening idiosyncratic events. Postmarketing evidence has shown that first-trimester exposure to topiramate monotherapy is associated with increased occurrence of cleft lip with or without cleft palate (Pregnancy Category D). Even though topiramate's long half-life would seemingly support q.d. dosing, randomized controlled migraine trials used b.i.d. administration of immediate-release (IR) topiramate, which has more favorable plasma concentration-time profile (ie, lower peak concentrations and higher trough concentrations) than q.d. IR dosing. Given the sensitivity of migraineurs to topiramate-related adverse events, particularly cognitive effects, pharmacokinetic profiles should be considered when optimizing migraine outcomes. The extended-release (XR) formulations Qudexy^® XR (Upsher-Smith Laboratories) and Trokendi XR^® (Supernus Pharmaceuticals) were specifically designed to achieve the adherence benefits of q.d. dosing but with more favorable (ie, more constant) steady-state plasma concentrations over the 24-hour dosing interval vs IR topiramate b.i.d. Intriguing results from a study in healthy volunteers showed consistently less impairment in neuropsychometric tests of verbal fluency and mental processing speed with an XR topiramate formulation (Trokendi XR) vs IR topiramate b.i.d. These findings suggest a pharmacodynamic effect associated with significantly reducing plasma concentration fluctuation when topiramate absorption is slowed. Results of retrospective studies in migraineurs treated with XR topiramate appear to support a clinically meaningful benefit of XR topiramate vs IR topiramate in terms of significantly fewer cognitive effects, improved adherence, and overall better outcomes of migraine prophylaxis with topiramate.

Topiramate for Treatment in Patients With Migraine and Epilepsy

BACKGROUND

Antiepileptic drugs (AED) are often considered first line for monotherapy in treatment of patients with migraines, and also those with comorbid migraine and epilepsy. Topiramate, a newer generation AED, has broad mechanism of action and evidence of benefit in patients with either episodic or chronic migraine along with epilepsy, both generalized and focal.

METHODS

Our goal is to review the relevant mechanisms of action along with any supportive evidence published to date on the use of topiramate (TPM) in patients with both migraine headache and epilepsy.

CONCLUSIONS

There has been very little published to date on the use of TPM in patients diagnosed with both disorders. Despite this, TPM has been adopted as first line therapy in this patient population. Future studies investigating the effectiveness of this treatment strategy are warranted in order to determine the most effective use of this medication in patients diagnosed with migraine headaches and epilepsy.

New players in the preventive treatment of migraine

Migraine is a common, chronic disorder of the brain causing much disability, as well as personal, familial and societal impact. Several oral preventive agents are available in different countries for the prevention of migraine, but none have performed better than 50% improvement in 50% of patients in a clinical trial. Additionally, each has various possible adverse events making their tolerability less than optimal. Recently, three monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) ligand (LY2951742, ALD403 and TEV-48125) and one targeting the CGRP receptor (AMG 334) have completed phase 2 trials, and the results have been reported. These early results show them all to be somewhat more effective than placebo, with no serious adverse events. Three have been studied for episodic migraine, and only TEV-48125 has been studied for both high frequency episodic and chronic migraine. Moreover, preliminary data suggests that neurostimulation is effective in migraine treatment, including stimulation of the sphenopalatine ganglion, transcutaneous supraorbital and supratrochlear nerve, and transcutaneous vagus nerve. In this article, these innovative therapies will be reviewed.

Nocebo effects and psychotropic drug action

The role of psychosocial context around patient and therapy can be studied through randomized clinical trials. The analysis of the results of clinical trials, and considering the adverse events (AEs) in the placebo groups, provides an important perspective of study for this phenomenon. In double-blind, randomized clinical trials, the side effects reported in placebo-treated groups are not associated with pharmacological treatment, but other factors should be taken into account to explain these symptoms. This phenomenon may be conceptualized as 'nocebo effects' relating to negative expectations for treatment outcome, even though a role of prior learning in the form of conditioning with active treatments cannot be excluded. This approach makes it possible to observe how associating the placebo groups with a particular drug can cause specific AEs that are consistent with those observed in the active group. This phenomenon was described in a systematic review that examined placebo AEs in tricyclic antidepressant randomized clinical trials. The authors depicted nocebo effects in antidepressant placebos similar to the AE profiles of the real drugs, which they were matched with. These key findings contrast with the belief that nocebo effects were simply nonspecific. Moreover, they emphasize the need to develop standardized procedures for collecting information about AEs in randomized, double-blind, placebo-controlled trials determining drug efficacy.

Topiramate and cognitive impairment: evidence and clinical implications

Topiramate is an antiepileptic drug (AED) with multiple mechanisms of action that has been shown to be effective in a number of neuropsychiatric disorders. However, cognitive dysfunction is frequently observed in such patients, often representing a relevant challenge in their management. Moreover, there is a long-held recognition that AEDs may profoundly affect cognitive functions. This paper reviews available data on cognitive adverse events in patients with neurological disorders treated with topiramate, discussing the role of different contributing factors such as the pharmacological properties of the drug, the specific features of the brain disorder, and other variables pertinent to the discussion. All studies agree that up to 10% of patients may complain of treatment-emergent adverse events on cognition. Such problems occur early during treatment (i.e. within 6 weeks) and emerge in a dose-dependent fashion, suggesting that such prevalence may be significantly reduced using the drug in monotherapy and adopting individualized doses and titration schedules. The magnitude of the problem is generally mild to moderate and the subjective perception of the patient needs to be taken into account. In fact, apart from language problems, data are not conclusive. Comparisons with new AEDs are limited to levetiracetam and lamotrigine, in both cases generally disfavoring topiramate, while data regarding first-generation AEDs show clear differences only for verbal fluency.

Pharmacogenomics of episodic migraine: time has come for a step forward

Migraine is characterized by heterogeneous behavior in response to drugs. Many resources have been invested in attempting to unravel the genetic basis of migraine, while the role of genetics in responses to currently available drugs has received less attention. We performed a systematic literature search identifying original articles pertaining to pharmacogenomics of episodic migraine. Few primary studies on the pharmacogenomics of symptomatic and preventive medication in episodic migraine were found. The number of patients studied in the individual articles ranged from 40 up to 130. There was a strong heterogeneity among these studies. We believe that pharmacogenomics studies, if properly designed, could contribute towards optimizing the treatment and reducing the burden of migraine, in turn helping patients and optimizing resources. Our knowledge on the pharmacogenomics of migraine is growing too slowly, and concerted measures should be undertaken to speed up the process.

Preventive pharmacologic treatments for episodic migraine in adults

OBJECTIVES

Systematic review of preventive pharmacologic treatments for community-dwelling adults with episodic migraine.

DATA SOURCES

Electronic databases through May 20, 2012.

ELIGIBILITY CRITERIA

English-language randomized controlled trials (RCTs) of preventive drugs compared to placebo or active treatments examining rates of ≥50 % reduction in monthly migraine frequency or improvement in quality of life.

STUDY APPRAISAL AND SYNTHESIS METHODS

We assessed risk of bias and strength of evidence and conducted random effects meta-analyses of absolute risk differences and Bayesian network meta-analysis.

RESULTS

Of 5,244 retrieved references, 215 publications of RCTs provided mostly low-strength evidence because of the risk of bias and imprecision. RCTs examined 59 drugs from 14 drug classes. All approved drugs, including topiramate (9 RCTs), divalproex (3 RCTs), timolol (3 RCTs), and propranolol (4 RCTs); off-label beta blockers metoprolol (4 RCTs), atenolol (1 RCT), nadolol (1 RCT), and acebutolol (1 RCT); angiotensin-converting enzyme inhibitors captopril (1 RCT) and lisinopril (1 RCT); and angiotensin II receptor blocker candesartan (1 RCT), outperformed placebo in reducing monthly migraine frequency by ≥50 % in 200-400 patients per 1,000 treated. Adverse effects leading to treatment discontinuation (68 RCTs) were greater with topiramate, off-label antiepileptics, and antidepressants than with placebo. Limited direct evidence as well as frequentist and exploratory network Bayesian meta-analysis showed no statistically significant differences in benefits between approved drugs. Off-label angiotensin-inhibiting drugs and beta-blockers were most effective and tolerable for episodic migraine prevention.

LIMITATIONS

We did not quantify reporting bias or contact principal investigators regarding unpublished trials.

CONCLUSIONS

Approved drugs prevented episodic migraine frequency by ≥50 % with no statistically significant difference between them. Exploratory network meta-analysis suggested that off-label angiotensin-inhibiting drugs and beta-blockers had favorable benefit-to-harm ratios. Evidence is lacking for long-term effects of drug treatments (i.e., trials of more than 3 months duration), especially for quality of life.

Topiramate: Effects on cognition in patients with epilepsy, migraine headache and obesity

This paper reviews the clinical implications of topiramate (TPM)-induced cognitive deficits in patients with epilepsy, migraine headache, obesity, and in normal populations, followed by reviews of the literature describing the reversal of such deficits upon medication discontinuation. It also discusses animal investigations of TPM's role of neuroprotection in brain injury. TPM's most intolerable adverse effects (AEs) are on verbal fluency and reaction time, resulting in high discontinuation rates in patients taking it for epilepsy and migraine headache. However, because TPM is so effective in the treatment of epilepsy and migraine headache, its use is expected to continue. There appears to be greater tolerance of TPM's cognitive AEs when it is used in the treatment of obesity, perhaps because of the lower doses required. Research attempting to predict the populations most vulnerable to the cognitive effects caused by TPM is ongoing. Studies suggest that one such population may include patients with a past psychiatric history. Slow titration and administration of the lowest possible doses may decrease risk of cognitive deficits.

Topiramate 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 topiramate 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 topiramate 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 topiramate and comparator (placebo, active control, or topiramate 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 selected quality of life instruments. Finally, we summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Twenty papers describing 17 unique trials met the inclusion criteria. Analysis of data from nine trials (1737 participants) showed that topiramate reduced headache frequency by about 1.2 attacks per 28 days as compared to placebo (MD -1.20; 95% confidence interval (CI) -1.59 to -0.80). Data from nine trials (1190 participants) show that topiramate approximately doubled the proportion of responders relative to placebo (RR 2.02; 95% CI 1.57 to 2.60; NNT 4; 95% CI 3 to 6). Separate analysis of different topiramate doses produced similar MDs versus placebo at 50 mg (-0.95; 95% CI -1.95 to 0.04; three studies; 520 participants), 100 mg (-1.15; 95% CI -1.58 to -0.71; six studies; 1620 participants), and 200 mg (-0.94; 95% CI -1.53 to -0.36; five studies; 804 participants). All three doses significantly increased the proportion of responders relative to placebo; ORs were as follows: for 50 mg, 2.35 (95% CI 1.60 to 3.44; three studies; 519 participants); for 100 mg, 3.49 (95% CI 2.23 to 5.45; five studies; 852 participants); and for 200 mg, 2.49 (95% CI 1.61 to 3.87; six studies; 1025 participants). All three doses also significantly improved three or more domains of quality of life as compared to placebo. Meta-analysis of the three studies that included more than one dose of topiramate suggests that 200 mg is no more effective than 100 mg. With regard to mean headache frequency and/or responder rate, seven trials using active comparators found (a) no significant difference between topiramate and amitriptyline (one study, 330 participants); (b) no significant difference between topiramate and flunarizine (one study, 83 participants); (c) no significant difference between topiramate and propranolol (two studies, 342 participants); (d) no significant difference between topiramate and relaxation (one study, 61 participants); but (e) a slight significant advantage of topiramate over valproate (two studies, 120 participants). Relaxation improved migraine-specific quality of life significantly more than topiramate. In trials of topiramate against placebo, seven adverse events (AEs) were reported by at least three studies. These were usually mild and of a non-serious nature. Except for taste disturbance and weight loss, there were no significant differences in the frequency of AEs in general, or of the seven specific AEs, between placebo and topiramate 50 mg. AEs in general and all of the specific AEs except nausea were significantly more common on topiramate 100 mg than on placebo, with NNHs varying from 3 to 25, and the RDs versus placebo were even higher for topiramate 200 mg, with NNHs varying from 2 to 17.

AUTHORS' CONCLUSIONS

Meta-analysis demonstrates that topiramate in a 100 mg/day dosage is effective in reducing headache frequency and reasonably well-tolerated in adult patients with episodic migraine. This provides good evidence to support its use in routine clinical management. More studies designed specifically to compare the efficacy or safety of topiramate versus other interventions with proven efficacy in the prophylaxis of migraine are needed.

Preventive treatment of migraine

Migraine is a prevalent and disabling episodic brain state with protean symptoms dominated by headache. When migraine attacks are frequent or severe over a sustained period, use of daily preventive medications are indicated to significantly reduce disability and improve quality of life. Recently issued evidence-based guidelines outline an array of pharmaceutical and complementary treatment choices with data establishing them as effective or probably effective for prevention of episodic or menstrually associated migraine. OnabotulinutoxinA is the only Food and Drug Administration-approved medication for the prevention of chronic migraine.

The performance of adverse effects search filters in MEDLINE and EMBASE

BACKGROUND

 Search filters can potentially improve the efficiency of searches involving electronic databases such as medline and embase. Although search filters have been developed for identifying records that contain adverse effects data, little is known about the sensitivity of such filters.

OBJECTIVES

 This study measured the sensitivity of using available adverse effects filters to retrieve papers with adverse effects data.

METHODS

  A total of 233 included studies from 26 systematic reviews of adverse effects were used for analysis. Search filters from medline and embase were tested for their sensitivity in retrieving the records included in these reviews. In addition, the sensitivity of each individual search term used in at least one search filter was measured.

RESULTS

 Subheadings proved the most useful search terms in both medline and embase. No indexing terms in medline achieved over 12% sensitivity. The sensitivity of published search filters varied in medline from 3% to 93% and in embase from 57% to 97%. Whether this level of sensitivity is acceptable will be dependent on the purpose of the search.

CONCLUSIONS

 Although no adverse effects search filter captured all the relevant records, high sensitivity could be achieved. Search filters may therefore be useful in retrieving adverse effects data.

Clinical pharmacology of topiramate in migraine prevention

INTRODUCTION

Migraine is a widespread disorder. Migraine patients experience worse health-related quality of life than the general population. The availability of effective and tolerable treatments for this disorder is an important medical need. This narrative review focuses on the clinical pharmacology of topiramate, an antiepileptic drug that was approved for the prophylaxis of migraine where it should act as a neuromodulator.

AREAS COVERED

A PubMed database search (from 2000 to 24 January 2011) and a review of the human studies published on topiramate and migraine was conducted.

EXPERT OPINION

Topiramate is an important option for the prophylaxis of migraine and is of proven efficacy and tolerability. It has also been studied in chronic migraine with encouraging results, even in patients with medication overuse. However, in migraine prevention its efficacy is comparable to the other first-line drugs and there are no published trials with a superiority design which can establish topiramate's role in the available therapeutic armamentarium.

Topiramate: safety and efficacy of its use in the prevention and treatment of migraine

Migraine headaches are typically episodic in nature and may affect nearly 10% of the population. In addition to treatment, prevention of subsequent episodes or progression to a chronic migraine state is an important therapeutic area. Topiramate is a centrally acting medication approved for both the prevention of seizures and migraine headache. At this time, the exact mechanism of how topiramate assists in migraine prevention is unknown. Several large randomized, controlled trials have aided in establishing topiramate's role in migraine prevention. Despite a favorable pharmacokinetic and adverse effect profile established in clinical trials, several additional studies, case reports and toxicology reports have demonstrated topiramate as a cause of cognitive and behavioural changes. The use of topiramate in migraine prevention can improve a patient's quality of life and is a cost-effective option for migraine prevention.

Nervous system adverse responses to topiramate in the treatment of neuropsychiatric disorders

IMPORTANCE OF THE FIELD

Nervous system adverse drug reactions (NS-ADRs), such as cognitive complaints and paresthesia, are among the most frequent and clinically important ADRs of topiramate. Studying ADR profiles across disorders is clinically relevant because treatment decision-making in neuropsychiatry is highly guided by ADR profiles.

AREAS COVERED IN THIS REVIEW

We used medline searches (until July 2009) to review the NS-ADRs of topiramate across the most investigated topiramate indications: alcohol dependence, essential tremor, binge-eating disorder, bulimia nervosa, migraine and epilepsy. We compared NS-ADRs between these disorders but did not carry out meta-analysis.

WHAT THE READER WILL GAIN

ADR profiles greatly differed between disorders. Drop-outs due to ADRs highly varied between disorders: from 2% in the bulimia nervosa group to 29% in the migraine group. Paresthesia was the most common NS-ADR for all disorders but frequencies also differed between disorders. Cognitive complaints were frequent and were reported in comparable proportions.

TAKE HOME MESSAGE

When prescribing topiramate in neuropsychiatry, physicians should be aware that NS-ADR profiles have been found to differ between disorders. Differences in drop-out rates due to ADRs and in frequencies of specific NS-ADRs across disorders must be taken into account when evaluating the potential harm of topiramate in clinical practice.