Topiramate in migraine prophylaxis

Comparing the Efficacy and Safety of Galcanezumab Versus Rimegepant for Prevention of Episodic Migraine: Results from a Randomized, Controlled Clinical Trial

INTRODUCTION

There have been no prior trials directly comparing the efficacy of different calcitonin gene-related peptide (CGRP) antagonists for migraine prevention. Reported are the results from the first head-to-head study of two CGRP antagonists, galcanezumab (monoclonal antibody) versus rimegepant (gepant), for the prevention of episodic migraine.

METHODS

In this 3-month, double-blind, double-dummy study, participants were randomized (1:1) to subcutaneous (SC) galcanezumab 120 mg per month (after a 240 mg loading dose) and a placebo oral disintegrating tablet (ODT) every other day (q.o.d.) or to rimegepant 75 mg ODT q.o.d. and a monthly SC placebo. The primary endpoint was the proportion of participants with a ≥ 50% reduction in migraine headache days per month from baseline across the 3-month double-blind treatment period. Key secondary endpoints were overall mean change from baseline in: migraine headache days per month across 3 months and at month 3, 2, and 1; migraine headache days per month with acute migraine medication use; Migraine-Specific Quality of Life Questionnaire Role Function-Restrictive domain score at month 3; and a ≥ 75% and 100% reduction from baseline in migraine headache days per month across 3 months.

RESULTS

Of 580 randomized participants (galcanezumab: 287, rimegepant: 293; mean age: 42 years), 83% were female and 81% Caucasian. Galcanezumab was not superior to rimegepant in achieving a ≥ 50% reduction from baseline in migraine headache days per month (62% versus 61% respectively; P = 0.70). Given the pre-specified multiple testing procedure, key secondary endpoints cannot be considered statistically significant. Overall, treatment-emergent adverse events were reported by 21% of participants, with no significant differences between study intervention groups.

CONCLUSIONS

Galcanezumab was not superior to rimegepant for the primary endpoint; however, both interventions demonstrated efficacy as preventive treatments in participants with episodic migraine. The efficacy and safety profiles observed in galcanezumab-treated participants were consistent with previous studies.

TRIAL REGISTRATION

ClinTrials.gov-NCT05127486 (I5Q-MC-CGBD).

European Headache Federation (EHF) critical reappraisal and meta-analysis of oral drugs in migraine prevention - part 3: topiramate

OBJECTIVE

Topiramate is a repurposed first-line treatment for migraine prophylaxis. The aim of this systematic review and meta-analysis is to critically re-appraise the existing evidence supporting the efficacy and tolerability of topiramate.

METHODS

A systematic search in MEDLINE, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov was performed for trials of pharmacological treatment in migraine prophylaxis as of August 13, 2022, following the Preferred Reporting Items for Systematic Reviews (PRISMA). Randomized controlled trials in adult patients that used topiramate for the prophylactic treatment of migraine, with placebo as active comparator, were included. Two reviewers independently screened the retrieved studies and extracted all data. Outcomes of interest were the 50% responder rates, the reduction in monthly migraine days, and adverse events leading to treatment discontinuation. Results were pooled and meta-analyzed, with sensitivity analysis based on the risk of bias of the studies, the monthly migraine days at baseline, and the previous use of other prophylactic treatments. Certainty evidence was judged according to the GRADE framework.

RESULTS

Eight out of 10,826 studies fulfilled the inclusion/exclusion criteria, accounting for 2,610 randomized patients. Six studies included patients with episodic migraine and two with chronic migraine. Topiramate dose ranged from 50 to 200 mg/day, and all studies included a placebo arm. There was a high certainty that topiramate: 1) increased the proportion of patients who achieved a 50% responder rate in monthly migraine days, compared to placebo [relative risk: 1.61 (95% confidence interval (CI): 1.29-2.01); absolute risk difference: 168 more per 1,000 (95% CI: 80 to 278 more)]; 2) was associated with 0.99 (95% CI: 1.41-0.58) fewer migraine days than placebo; 3) and had a higher proportion of patients with adverse events leading to treatment discontinuation [absolute risk difference 80 patients more per 1,000 (95% CI: 20 to 140 more patients)].

CONCLUSIONS

There is high-quality evidence of the efficacy of topiramate in the prophylaxis of migraine, albeit its use poses a risk of adverse events that may lead to treatment discontinuation, with a negative effect on patient satisfaction and adherence to care.

Narrative Review of Topiramate: Clinical Uses and Pharmacological Considerations

Due to the diverse mechanisms of action of antiseizure drugs, there has been a rise in prescriptions of these drugs for non-epileptic pathologies. One drug that is now being used for a variety of conditions is topiramate. This is a narrative review that used PubMed, Google Scholar, MEDLINE, and ScienceDirect to review literature on the clinical and pharmacologic properties of topiramate. Topiramate is a commonly prescribed second-generation antiseizure drug. The drug works through multiple pathways to prevent seizures. In this regard, topiramate blocks sodium and calcium voltage-gated channels, inhibits glutamate receptors, enhances gamma-aminobutyric acid (GABA) receptors, and inhibits carbonic anhydrase. Topiramate is approved by the Food and Drug Administration (FDA) for epilepsy treatment and migraine prophylaxis. Topiramate in combination with phentermine is also FDA-approved for weight loss in patients with a body mass index (BMI) > 30. The current target dosing for topiramate monotherapy is 400 mg/day and 100 mg/day to treat epilepsy and migraines, respectively. Commonly reported side effects include paresthesia, confusion, fatigue, dizziness, and change in taste. More uncommon and serious adverse effects can include acute glaucoma, metabolic acidosis, nephrolithiasis, hepatotoxicity, and teratogenicity. Related to a broad side effect profile, physicians prescribing this drug should routinely monitor for side effects and/or toxicity. The present investigation reviews various anti-seizure medications before summarizing indications of topiramate, off-label uses, pharmacodynamics, pharmacokinetics, adverse effects, and drug-drug interactions.

Topiramate (Topamax): Evolving Role in Weight Reduction Management: A Narrative Review

Obesity has emerged as a widespread disease with epidemic proportions, necessitating effective management to enhance the overall health outcomes of patients. Medical intervention for weight loss becomes necessary when diet and exercise prove ineffective, and topiramate emerges as a potential treatment option for this global problem. Currently approved as an anti-epileptic and migraine prophylaxis medication, topiramate is frequently utilized as adjunctive therapy for patients with mood and eating disorders, as well as for alcohol use disorders. Its multifaceted mechanisms of action contribute to reducing neuronal excitation and enhancing neuronal inhibition. Given its variety of mechanisms, topiramate shows several off-label outcomes, including weight loss, for patients prescribed this medication. Although the specific mechanism of action concerning weight loss remains uncertain, various hypotheses have been reported. Notably, topiramate may contribute to weight loss by reducing calorie intake, decreasing fat gain, and lowering triglyceride and cholesterol levels. Additionally, its impact on reward pathways associated with food could play a role. Multiple clinical studies have supported the use of topiramate as a weight-loss medication. Notably, the medication demonstrates effectiveness in reducing body weight across different dosages and sustaining weight loss over time, outperforming alternative weight loss methods. Moreover, it was generally well-tolerated in clinical studies, with few side effects observed. In conclusion, topiramate offers promising potential as a weight loss solution and can be a valuable addition to the range of treatment options for combating obesity.

The effect of blood pressure lowering medications on the prevention of episodic migraine: A systematic review and meta-analysis

BACKGROUND

Currently, only a few specific blood pressure-lowering medications are recommended for migraine prevention. Whether benefits extend to other classes or drugs is uncertain.

METHODS

Embase, MEDLINE, and the Cochrane Central Registry of Controlled Trials were searched for randomized control trials on the effect of blood pressure-lowering medications compared with placebo in participants with episodic migraine. Data were collected on four outcomes - monthly headache or migraine days, and monthly headache or migraine attacks, with a standardised mean difference calculated for overall. Random effect meta-analysis was performed.

RESULTS

In total, 50 trials (70% of which were crossover) were included, comprising 60 comparisons. Overall mean age was 39 years, and 79% were female. Monthly headache days were fewer in all classes compared to placebo, and this was statistically significant for all but one class: alpha-blockers -0.7 (95% CI: -1.2, -0.1), angiotensin-converting enzyme inhibitors -1.3 (95% CI: -2.9, 0.2), angiotensin II receptor blockers -0.9 (-1.6, -0.1), beta-blocker -0.4 (-0.8, -0.0) and calcium channel blockers -1.8 (-3.4, -0.2). Standardised mean difference was significantly reduced for all drug classes and was separately significant for numerous specific drugs: clonidine, candesartan, atenolol, bisoprolol, metoprolol, propranolol, timolol, nicardipine and verapamil.

CONCLUSION

Among people with episodic migraine, a broader number of blood pressure-lowering medication classes and drugs reduce headache frequency than those currently included in treatment guidelines.Trial Registration: The study was registered at PROSPERO (CRD42017079176).

Intensive Mindfulness Meditation Reduces Frequency and Burden of Migraine: An Unblinded Single-Arm Trial

Objectives

Preventing migraine headaches and improving the quality of life for patients with migraine remains a challenge. We hypothesized intensive meditation training would reduce the disease burden of migraine.

Method

An unblinded trial was analyzed as a single cohort exposed to a silent 10-day Vipassana meditation retreat that included 100 hr of sitting meditation. Participants with chronic or episodic migraine were enrolled and followed for 1 year. The primary outcome was a change in mean monthly migraine days at 12 months from baseline. Secondary outcomes included headache frequency and intensity, acute medication use, work days missed, home meditation, sleep quality, general health, quality of life, migraine impact, positive and negative affect, perceived stress, mindfulness, and pain catastrophizing.

Results

Three hundred people were screened and 58 (19%) agreed to participate and enrolled in the intensive meditation training. Forty-six participants with chronic migraine (≥ 15 headaches/month of which ≥ 8 were migraines) and 12 with episodic migraine (< 15 and ≥ 4 migraines/month) attended and 45 (78%) completed the retreat. At 12 months, the average migraine frequency was reduced by 2.7 days (from 16.6 at baseline) per 28 days (95%CI - 4.3, - 1.3) and headaches by 3.4 (20.1 at baseline) per 28 days (- 4.9, - 1.9). Fifty percent responder rate was 29% for migraine. Acute medication use dropped by an average of 2.2 days (- 3.9, - 0.5) per 28 days, and participants reported 2.3 fewer days (- 4.0, - 0.5) on which they reduced their activity due to migraines. The most striking and promising effects were in several secondary outcomes, including migraine-specific quality of life, pain catastrophizing, and perceived stress. The significant improvements observed immediately following the intervention were sustained at 12 months follow-up.

Conclusions

Training in Vipassana meditation via a 10-day retreat may reduce the frequency and burden of migraine.

Preregistration

ClinicalTrials.gov: NCT00663585.

Primary headache types in adult epilepsy patients

BACKGROUND

Headache is among the most common comorbidities in epilepsy. This study examined the distribution of different primary headache disorders in a large cohort of patients with diagnosed epilepsy. Headache types were analysed with regard to gender, type of epilepsy and antiepileptic drugs (AEDs).

METHODS

In this prospective single-centre study, 500 patients with epilepsy (250 female, mean age: 45.52 ± 17.26 years) were evaluated with regards to primary headache types using a validated German headache questionnaire categorizing for migraine (MIG), tension-type headache (TTH) or trigeminal autonomic cephalalgias (TAC), their combinations and unclassifiable headache. Data regarding type of epilepsy, seizure-associated headache, AED treatment and seizure freedom were collected.

RESULTS

Of 500 patients with epilepsy, 163 (32.6%) patients (108 female and 55 male) reported suffering from headaches at least 1 day per month. MIG (without aura, with aura) and TTH were the most frequent headache type (MIG 33.1%, TTH 33.1%). Female epilepsy patients reported headaches significantly more often than male patients (x² = 8.20, p = 0.0042). In contrast, the type of epilepsy did not significantly affect headache distribution. Of 163 patients with headache, 66 (40.5%) patients reported seizure-associated headache and AEDs were used by 157 patients. Of importance, patients with AED monotherapy suffered from MIG less often when compared to patients on polytherapy (x² = 4.79, p = 0.028).

CONCLUSION

MIG and TTH are the most common headache types in epilepsy patients and headache is more frequent among female epilepsy patients. Monotherapy in AEDs might have a beneficial effect on the frequency of headache compared to polytherapy.

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.

Erenumab versus topiramate: post hoc efficacy analysis from the HER-MES study

OBJECTIVE

HER-MES was the first head-to-head, phase 4 trial to assess the tolerability and effectiveness of erenumab against standard of care treatment (topiramate). This post hoc analysis compared the efficacy of erenumab with topiramate in patients who completed the trial on study medication.

METHODS

Post hoc sensitivity analysis was performed using the full analysis set. Outcomes assessed included the proportion of patients with a ≥50% reduction in monthly migraine days (MMD) from baseline (50% responder rate), over the last 3 months (months 4, 5, and 6) of the double-blind treatment phase (DBTP), the 50% responder rate during the first month of the DBTP, and change from baseline in MMD during the DBTP. Multiple imputation was done for efficacy values of patients who discontinued study treatment.

RESULTS

Patients (N = 777) were randomly assigned (1:1) to either 70 or 140 mg/month erenumab (N = 389) or 50-100 mg/day topiramate (N = 388). Of these, 334 patients (85.9%) receiving erenumab, and 231 patients (59.5%) receiving topiramate completed the DBTP on study medication. Patients on study medication until the end of the DBTP received a mean dose of 119 mg/month for erenumab and 92 mg/day for topiramate. At month 1, a significantly greater proportion of patients receiving erenumab (39.2%) reported ≥50% reduction in MMD from baseline compared with those receiving topiramate (24.0%; p < 0.001). In the last 3 months, a significantly larger proportion of patients receiving erenumab (60.3%) achieved ≥50% reduction in MMD from baseline compared with those receiving topiramate (43.3%; p < 0.001). Patients receiving erenumab demonstrated significantly greater reductions in MMD during the last 3 months from baseline versus those receiving topiramate (- 6.13 vs - 4.90; 95% CI: - 1.87 to - 0.61; p < 0.001).

CONCLUSIONS

This post hoc analysis demonstrated significantly superior efficacy of erenumab versus topiramate in achieving a ≥50% reduction in MMD with an early onset of efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03828539 .

Consensus of the Brazilian Headache Society (SBCe) for the Prophylactic Treatment of Episodic Migraine: part I

The Brazilian Headache Society (Sociedade Brasileira de Cefaleia, SBCe, in Portuguese) nominated a Committee of Authors with the aim of establishing a consensus with recommendations regarding prophylactic treatment for episodic migraine based on articles published in the worldwide literature, as well as personal experience. Migraine affects 1 billion people around the world and more than 30 million Brazilians. In addition, it is an underdiagnosed and undertreated disorder. It is well known within the medical community of neurologists, and especially among headache specialists, that there is a need to disseminate knowledge about prophylactic treatment for migraine. For this purpose, together with the need for drug updates and to expand knowledge of the disease itself (frequency, intensity, duration, impact and perhaps the progression of migraine), this Consensus was developed, following a full online methodology, by 12 groups who reviewed and wrote about the pharmacological categories of the drugs used and, at the end of the process, met to read and establish conclusions for this document. The drug classes studied were: anticonvulsants, tricyclic antidepressants, monoclonal anti-calcitonin gene-related peptide (anti-CGRP) antibodies, beta-blockers, antihypertensives, calcium channel inhibitors, other antidepressants (selective serotonin reuptake inhibitors, SSRIs, and dual-action antidepressants), other drugs, and polytherapy. Hormonal treatment and anti-inflammatories and triptans in minimum prophylaxis schemes (miniprophylaxis) will be covered in a specific chapter. The drug classes studied for part I of the Consensus were: anticonvulsants, tricyclic antidepressants, monoclonal anti-CGRP antibodies, and beta-blockers.

TOP-PRO study: A randomized double-blind controlled trial of topiramate versus propranolol for prevention of chronic migraine

OBJECTIVE

The aim of the TOP-PRO-study, a double-blind randomized controlled trial, was to assess the efficacy (non-inferiority) and tolerability of propranolol compared to topiramate for the prevention of chronic migraine.

BACKGROUND

Except for topiramate, oral preventive treatment for chronic migraine lacks credible evidence.

METHODS

Chronic migraine patients aged above 18 years and less than 65 years of age, not on any preventive treatment were randomly allocated to receive topiramate (100 mg/day) or propranolol (160 mg/day). The primary efficacy outcome was the mean change in migraine days per 28 days at the end of 24 weeks from baseline. A mean difference of 1.5 days per four weeks was chosen as the cut-off delta value. Multiple secondary efficacy outcomes and treatment emergent adverse events were also assessed.

RESULTS

As against the planned sample size of 244, only 175 patients could be enrolled before the spread of the corona virus disease-2019 pandemic and enforcement of lockdown in India. Of the 175 randomized patients, 95 (topiramate 46 and propranolol 49) completed the trial. The mean change in migraine days was -5.3 ± 1.2 vs -7.3 ± 1.1 days (p = 0.226) for topiramate and propranolol groups respectively. Propranolol was found to be non-inferior and not superior to topiramate (point estimate of -1.99 with a 95% confidence interval of -5.23 to 1.25 days). Multiple secondary outcomes also did not differ between the two groups. Intention to treat analysis of 175 patients and per-protocol analysis of 95 patients yielded concordant results. There was no significant difference in the incidence of adverse events between the two groups.

CONCLUSION

Propranolol (160mg/day) was non-inferior, non-superior to topiramate (100mg/day) for the preventive treatment of chronic migraine and had a comparable tolerability profile.Trial Registration: Clinical Trials Registry-India CTRI/2019/05/018997).

CGRP monoclonal antibodies in migraine: an efficacy and tolerability comparison with standard prophylactic drugs

BACKGROUND

Several drugs are available for the preventive treatment of both episodic and chronic migraine. The choice of which therapy to initiate first, second, or third is not straightforward and is based on multiple factors, including general efficacy, tolerability, potential for serious adverse events, comorbid conditions, and costs. Recently, a new class of migraine preventive drugs was introduced, i.e. monoclonal antibodies against calcitonin gene-related peptide (CGRP) or its receptor.

METHODS

The present article summarizes the evidence gathered with this new migraine preventive drug class from randomized placebo-controlled clinical trials. It further puts this into perspective next to the evidence gained by the most widely used agents for the prevention of episodic and chronic migraine with an emphasis on efficacy and the robustness with which this efficacy signal was obtained.

RESULTS

Although being a relatively new class of migraine preventive drugs, monoclonal antibodies blocking the CGRP pathway have an efficacy which is at least comparable if not higher than those of the currently used preventive drugs. Moreover, the robustness of this efficacy signal is substantiated by several randomized clinical trials each including large numbers of patients. In addition, because of their excellent tolerability and with long-term safety data emerging, they seem to have an unprecedented efficacy over adverse effect profile, clearly resulting in an added value for migraine prevention.

CONCLUSIONS

Balancing the data presented in the current manuscript with additional data concerning long term safety on the one hand and cost issues on the other hand, can be of particular use to health policy makers to implement this new drug class in the prevention of migraine.

Advances in topiramate as prophylactic treatment for migraine

It is well-known that topiramate as a kind of antiepileptic drug has been proved effective for migraine prevention in North America and Europe. However, topiramate is still viewed as an off-label medication for migraine treatment in China, partly because of the limited evidence in Chinese patients. We summarize the effects of topiramate on the frequency, severity, quality-of-life, and adverse event among migraine patients, including children and adolescent in this review, so as to provide reference for Chinese doctors.

The efficacy and safety of antiepileptics in the prophylaxis of pediatric migraine: the meta-analysis of randomized controlled trials

BACKGROUND

Migraine is the most common primary headache among children and adolescents. The aim of this meta-analysis was to evaluate the efficacy and safety of antiepileptic drugs in the prevention of pediatric migraine.

METHODS

PubMed, Cochrane Library, EMBASE and Chinese National Knowledge Infrastructure (CNKI) databases were searched for eligible published RCTs from January 1970 to June 2020. Migraine frequency and ≥50% response rate were measured as the efficacy outcomes. We used "Risk of Bias" tool for quality assessment and RevMan5.3 software for statistical analysis.

RESULTS

Four articles containing 7 RCTs with 794 participants compared the efficacy of AEDs with placebo. Four RCTs assessed topiramate vs. placebo and 3 RCTs evaluated divalproex sodium extended-release (DVPX ER) vs. placebo. The results demonstrated that children receiving antiepileptic drugs had a significant advantage in remitting the mean monthly migraine days compared to those who received placebo, with an MD of -0.48 (n=930, 95% CI: -0.84 to -0.12, Z=2.60, P=0.009). Topiramate significantly reduced monthly migraine days (MD =-0.70, n=489, 95% CI: -1.16 to -0.25, Z=3.01, P=0.003) but failed to improve the ≥50% response rate (MD =-1.50, n=489, 95% CI: 0.70 to 3.22, Z=1.05, P=0.30). DVPX ER did not significantly reduce monthly headache frequency (n=441, 95% CI: -0.70 to 0.47, Z=0.38, P=0.70) or improve the ≥50% response rate (n=441, 95% CI: 0.59 to 1.25, Z=0.82, P=0.41) compared with placebo. Topiramate and DVPX ER were related to higher rates of side effects and adverse reactions.

DISCUSSION

Topiramate can reduce monthly headache days in children and adolescents with migraine. However, it failed to improve the ≥50% response rate. DVPX ER showed no difference from placebo in the prophylactic treatment pediatric migraine. Side effects seemed to be more frequent in topiramate and DVPX ER treated children but generally well-tolerated.

CGRP-antibodies, topiramate and botulinum toxin type A in episodic and chronic migraine: A systematic review and meta-analysis

Background

The approval of monoclonal antibodies for prevention of migraine has revolutionized treatment for patients. Oral preventatives are still considered first line treatments as head-to-head trials comparing them with antibodies are lacking.

Methods

The main purpose of this study was to provide a comparative overview of the efficacy of three commonly prescribed migraine preventative medication classes. For this systematic review and meta-analysis, we searched the databases CENTRAL, EMBASE, and MEDLINE until 20 March 2020. We included RCTs reporting the 50% response rates for topiramate, Botulinum Toxin Type A and monoclonal antibodies against CGRP(r). Studies were excluded if response rates were not reported, treatment allocation was unclear, or if study quality was insufficient. Primary outcome measure were the 50% response rates. The pooled odds ratios with 95% confidence intervals were calculated with the random effects model. The study was registered at PROSPERO (CRD42020222880).

Findings

We identified 6552 reports. Thirty-two were eligible for our review. Studies assessing monoclonal antibodies included 13,302 patients and yielded pooled odds ratios for the 50% response rate of 2.30 (CI: 2.11–2.50). Topiramate had an overall effect estimate of 2.70 (CI: 1.97–3.69) with 1989 included patients and Botulinum Toxin Type A achieved 1.28 (CI: 0.98–1. 67) with 2472 patients included.

Interpretation

Topiramate, botulinum toxin type A and monoclonal antibodies showed higher odds ratios in achieving a 50% response rate compared to placebo. Topiramate numerically demonstrated the greatest effect size but also the highest drop-out rate.

Anti-CGRP monoclonal antibodies for migraine prevention: A systematic review and likelihood to help or harm analysis

INTRODUCTION AND OBJECTIVE

Monoclonal antibodies targeting the calcitonin gene-related peptide pathway (anti-CGRP mAbs) have shown promising efficacy in randomised clinical trials for the prevention of episodic and chronic migraine, but no head-to-head comparisons with established treatments are available. We aimed to examine absolute differences in benefit-risk ratios between anti-CGRP mAbs, topiramate and propranolol for the prevention of episodic migraine and between anti-CGRP mAbs, topiramate and onabotulinumtoxinA for the prevention of chronic migraine using a likelihood to help versus harm analysis.

METHODS

The number of patients needed to be treated for a patient to achieve ≥ 50% reduction in migraine days (NNTB_50%) was used as an effect size metric of efficacy. The number of patients needed to be treated for a patient to experience an adverse event that led to treatment discontinuation (NNTH_D-AE) was used as a measure of risk. Likelihood to help versus harm values - which are the ratios of NNTH:NNTB - were calculated using data from phase 3 randomised clinical trials.

RESULTS

All agents tested were more likely to be beneficial than harmful (likelihood to help versus harm > 1) with the exception of topiramate at 200 mg per day for the prevention of episodic migraine. Anti-CGRP mAbs in all tested doses had higher LHH values than propranolol or topiramate for episodic migraine and onabotulinumtoxinA or topiramate for chronic migraine prevention. Fremanezumab had the highest LHH ratio in episodic migraine and galcanezumab in chronic migraine.

CONCLUSION

This analysis showed that anti-CGRP mAbs exhibit a more favourable benefit-risk ratio than established treatments for episodic and chronic migraine. Head-to-head studies are needed to confirm these results.

Indirect Comparison of Topiramate and Monoclonal Antibodies Against CGRP or Its Receptor for the Prophylaxis of Episodic Migraine: A Systematic Review with Meta-Analysis

BACKGROUND

Head-to-head comparator trials between first-line oral migraine preventatives and the new monoclonal antibodies (mAbs) blocking the calcitonin gene-related peptide (CGRP) pathway have not been published to date.

OBJECTIVES

This study aimed to indirectly compare the clinical efficacy and safety of mAbs against CGRP or its receptor (CGRPR) and topiramate in episodic migraine prophylaxis using meta-analysis.

METHODS

We included controlled trials testing efficacy and safety of erenumab, galcanezumab, fremanezumab, eptinezumab, and topiramate in adults diagnosed with episodic migraine. We searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov from January 2000 to November 2020. We used the Risk of Bias 2 (RoB2) tool to assess the risk of bias and report pooled mean effects (mean difference and risk ratio) as estimated in a random effect model. For efficacy analysis, we determined the reduction of monthly migraine days (MMDs), reduction of days with acute medication (AMDs), and 50% responder rates (50% RR). For safety, we determined adverse events (AEs) occurring in ≥ 2% of study participants and the number of patients who discontinue treatment due to AEs (DAEs). The number needed to treat (NNT) and to harm (NNH) were estimated as well as the likelihood to help or harm (LLH).

RESULTS

We included 13 trials involving 7557 patients: three trials with erenumab, two trials with galcanezumab, two trials with fremanezumab, one trial with eptinezumab, and five trials with topiramate, for the prophylaxis of episodic migraine in adults. The placebo-subtracted reduction (pooled mean difference) of MMDs were - 1.55 (95% CI - 1.86 to - 1.24; active drug n = 3326 vs placebo n = 2219, 8 studies) for the CGRP(R) mAb and - 1.11 (95% CI - 1.62 to - 0.59; active drug n = 1032 vs placebo n = 543, 4 studies) for topiramate (p for subgroup difference = 0.15). 'Cognitive' and 'sensory & pain'-related adverse events occurred more often in patients treated with topiramate compared with those treated with a CGRP(R) mAb (p for subgroup difference 0.03 and < 0.001, respectively). Based on the 50% RR and DAE, the NNT, NNH, and LHH for the CGRP(R) mAbs were 6, 130, and 24.3:1, respectively. For topiramate, these values were 7, 9, and 1.8:1, respectively.

CONCLUSION

The efficacy of CGRP(R) mAbs to reduce migraine days does not differ from topiramate. However, the safety profile is in favor of the CGRP(R) mAbs, with a higher likelihood to help than to harm compared with topiramate. The diversity of endpoint determination and the heterogeneity between studies for some endpoints cause some limitations for this study.

Eptinezumab Demonstrated Efficacy in Sustained Prevention of Episodic and Chronic Migraine Beginning on Day 1 After Dosing

Objective

To determine the onset of preventive efficacy with eptinezumab in patients with migraine.

Background

Eptinezumab is a monoclonal antibody inhibiting calcitonin gene‐related peptide approved as an intravenously administered treatment for the prevention of migraine.

Methods

Patients who received eptinezumab 100 mg, eptinezumab 300 mg, or placebo in PROMISE7‐1 (episodic migraine; 100 mg, n = 221; 300 mg, n = 222; placebo, n = 222) or PROMISE7‐2 (chronic migraine; 100 mg, n = 356; 300 mg, n = 350; placebo, n = 366) were included. Testing of the percentage of patients with a migraine on day 1 after dosing was prespecified and alpha‐controlled. In further exploration of this prespecified endpoint, a post hoc closed testing procedure, which controlled the false‐positive (type 1) error rate, provided a statistically rigorous evaluation of migraine prevention onset. The procedure involved up to 84 tests of significance, all of which were performed in sequence until the first nonsignificant result.

Results

For both studies, all tests for significance for eptinezumab 100 and 300 mg, from days 1‐84 through day 1 alone, achieved nominal significance (P < .05), indicating that eptinezumab was fully effective beginning on day 1. Over each interval, the treatment effect was comparable to the effect over weeks 1‐12. Mean changes from baseline in monthly migraine days for the primary endpoint period ranged from −3.9 to −4.9, −4.1 to −4.9, and −2.2 to −3.2 for eptinezumab 100, 300 mg, and placebo, respectively, in PROMISE7‐1 and from −7.2 to −8.0, −7.9 to −8.2, and −4.3 to −5.6, respectively, in PROMISE7‐2. The difference from placebo (95% confidence interval) in day 1 treatment effect was −2.2 (−4.1, −0.3) and −2.5 (−4.4, −0.6) days/month for eptinezumab 100 and 300 mg, respectively, in PROMISE7‐1, and was −3.8 (−5.6, −2.0) and −4.0 (−5.8, −2.1) days/month for 100 and 300 mg, respectively, in PROMISE7‐2.

Conclusions

The migraine preventive effect of eptinezumab is rapid and sustained in patients with episodic or chronic migraine, with onset of optimal preventive efficacy observed on the day following the initial dose.

Understanding Drug Repurposing From the Perspective of Biomedical Entities and Their Evolution: Bibliographic Research Using Aspirin

BACKGROUND

Drug development is still a costly and time-consuming process with a low rate of success. Drug repurposing (DR) has attracted significant attention because of its significant advantages over traditional approaches in terms of development time, cost, and safety. Entitymetrics, defined as bibliometric indicators based on biomedical entities (eg, diseases, drugs, and genes) studied in the biomedical literature, make it possible for researchers to measure knowledge evolution and the transfer of drug research.

OBJECTIVE

The purpose of this study was to understand DR from the perspective of biomedical entities (diseases, drugs, and genes) and their evolution.

METHODS

In the work reported in this paper, we extended the bibliometric indicators of biomedical entities mentioned in PubMed to detect potential patterns of biomedical entities in various phases of drug research and investigate the factors driving DR. We used aspirin (acetylsalicylic acid) as the subject of the study since it can be repurposed for many applications. We propose 4 easy, transparent measures based on entitymetrics to investigate DR for aspirin: Popularity Index (P₁), Promising Index (P₂), Prestige Index (P₃), and Collaboration Index (CI).

RESULTS

We found that the maxima of P₁, P₃, and CI are closely associated with the different repurposing phases of aspirin. These metrics enabled us to observe the way in which biomedical entities interacted with the drug during the various phases of DR and to analyze the potential driving factors for DR at the entity level. P₁ and CI were indicative of the dynamic trends of a specific biomedical entity over a long time period, while P₂ was more sensitive to immediate changes. P₃ reflected the early signs of the practical value of biomedical entities and could be valuable for tracking the research frontiers of a drug.

CONCLUSIONS

In-depth studies of side effects and mechanisms, fierce market competition, and advanced life science technologies are driving factors for DR. This study showcases the way in which researchers can examine the evolution of DR using entitymetrics, an approach that can be valuable for enhancing decision making in the field of drug discovery and development.

Topiramate for smoking cessation: Systematic review and meta-analysis

INTRODUCTION

Topiramate is an antiepileptic drug that has been used for many labeled and off-labeled indications. It may be useful in reducing withdrawal symptoms of various addictive agents such as alcohol, cocaine, cannabis and smoking. To date, some studies have examined the effectiveness of topiramate for smoking cessation. The present review aims to synthesize the results from those studies and determine topiramate effectiveness in smoking cessation.

METHODS

A comprehensive search was conducted in the databases: PubMed/Medline, Cochrane, Egyptian Knowledge Bank, and Google Scholar. All clinical trials that examined the effect of topiramate, compared with the placebo, on smoking cessation rate were included. Statistical analysis using fixed effect models, heterogeneity and sensitivity analysis were conducted using RevMan 5.3.

RESULTS

Five trials met the inclusion criteria and were included in the meta-analysis. Topiramate non-significantly increased prolonged smoking abstinence rate (OR=1.19, 95% CI: 0.57–2.5) compared with the placebo. On the other hand, topiramate significantly increased the abstinence rate at weeks 4, 6, 8 and 12 (OR=3.07, 95% CI: 1.19–7.93; OR=4.03, 95% CI: 1.98–8.2; OR=2.29, 95% CI: 1.23–4.28; and OR=2.45, 95% CI: 1.37–4.39; respectively) compared with the placebo.

CONCLUSIONS

Based on the five trials, where publication bias cannot be excluded, the current evidence is not sufficient to show a significant difference to favor topiramate in prolonged smoking cessation over the placebo, although the 12th week point prevalence favored topiramate.

Placebo and nocebo phenomena in anti- CGRP monoclonal antibody trials for migraine prevention: a meta-analysis

High placebo and low nocebo phenomena mirror high positive expectations for a novel treatment, among other reasons. In a meta-analysis aimed to identify placebo and nocebo phenomena in the placebo-controlled randomized trials (RCTs) with the monoclonal antibodies targeting the calcitonin gene-related peptide pathway (anti-CGRP mAbs) all the placebo-treated patients were pooled and compared with the placebo-treated patients in RCTs with topiramate and onabotulinum toxin A (OBTA). In episodic migraine (EM), the proportion of placebo-treated patients who achieved the 50% responder rate (placebo) was 32.7% (95% CI 28.6%-37.0%) in anti-CGRP mAbs vs. 24.4% (95% CI 20.5%-28.5%) in topiramate trials. The proportion of dropouts due to adverse events in placebo-treated patients (nocebo) was 1.9% (95% CI 1.4%-2.6%) in anti-CGRP mAbs vs. 9.9% (95% CI 7.7%-12.3%) in topiramate RCTs. In chronic migraine (CM), the placebo 50% responder rate was 23.6% (95% CI 11.2%-38.8%) in anti-CGRP mAbs RCTs vs. 36.4% (95% CI 32.6%-39.3%) in RCTs with OBTA. The nocebo dropout in anti-CGRP mAbs and OBTA RCTs was 1.4% (95% CI 0.8%-2.1%) and 0.9 (95% CI 0.3%-1.7%), respectively. The stronger placebo and weaker nocebo phenomena in RCTs with anti-CGRP mAbs vs. those with topiramate in the prophylaxis of EM, may decisively determine anti-CGRP mAbs treatment success. No differences were detected between the anti-CGRP mAbs and OBTA in the treatment of CM.

The crossover design for migraine preventives: an analyses of four randomized placebo-controlled trials

Aims

To evaluate the crossover design in migraine preventive treatment trials by assessing dropout rate, and potential period and carryover effect in four placebo-controlled randomized controlled trials (RCTs).

Methods

In order to increase statistical power, the study combined data from four different RCTs performed from 1998 to 2015 at St. Olavs Hospital, Norway. Among 264 randomized patients, 120 received placebo treatment before and 144 after active treatment.

Results

Only 26 (10%) dropped out during the follow-up period of 30–48 weeks, the majority (n = 19) in the first 12 weeks. No period effect was found, since the treatment sequence did not influence the responder rate after placebo treatment, being respectively for migraine 30.5% vs. 27.4% (p = 0.59) and for headache 25.0% vs. 24.8% (p = 0.97, Chi-square test) when placebo occurred early or late. Furthermore, no carryover effect was identified, since the treatment sequence did not influence the treatment effect (difference between placebo and active treatment). There was no significant difference between those who received active treatment first and those who received placebo first with respect to change in number of days per 4 week of headache (− 0.9 vs. -1.3, p = 0.46) and migraine (− 1.2 vs. -0.9, p = 0.35, Student’s t-test).

Conclusions

Summary data from four crossover trials evaluating preventive treatment in adult migraine showed that few dropped out after the first period. No period or carryover effect was found. RCT studies with crossover design can be recommended as an efficient and cost-saving way to evaluate potential new preventive medicines for migraine in adults.

Problematic presentation and use of efficacy measures in current trials of CGRP monoclonal antibodies for episodic migraine prevention: A mini-review

Background

In trials of monoclonal antibodies against calcitonin gene-related peptide or its receptor for prevention of episodic migraine, we observed two problematic aspects: a) The graphic presentations; b) the methods of calculating “response rates” (≥50% decrease of monthly migraine days from baseline).

Observations

Decrease in monthly migraine days is presented, over time, in figures on a downward (negative) scale from zero at baseline, with the ordinate stopped just beyond the maximum effect of the active drugs. In one trial, decreases in monthly migraine days were −1.8 after placebo, −3.2 after erenumab 70 mg and −3.7 after erenumab 140 mg, with the ordinate stopped at −4.5. The reader can perceive only a relative 2-fold benefit of erenumab versus placebo. If, however, treatment periods are compared with baseline in bar charts, MMDs persisting after treatment in the same trial can be illustrated as follows, creating a different perception: 78% for placebo, 61% for erenumab 70 mg, and 55% for erenumab 140 mg. In the nine trials, “response rates” defined as above were calculated in five different ways, taking different numbers of treatment months into account in comparisons with the one-month baseline. This makes comparisons impossible.

Suggestions for improvements

Mean monthly migraine days before and after treatment should be presented in a bar chart. Such figures, presenting persisting MMDs, are more clinically relevant and less misleading than decreases from baseline. The definition and methods of calculating and presenting “50% response rates” should be standardized by the Drug Trial Committee of the International Headache Society.

Health state utilities associated with attributes of migraine preventive treatments based on patient and general population preferences

Purpose

While previous studies have estimated health state utilities associated with migraine severity and frequency, migraine treatments vary in other ways that may have an impact on patients’ quality of life, preference, and utility. The purpose of this study was to estimate utilities associated with migraine treatment attributes including route of administration and treatment-related adverse events (AEs).

Methods

In time trade-off interviews, migraine patients and general population participants in the UK valued health state vignettes drafted based on literature, medication labels, and clinician interviews. All respondents valued migraine health states varying in route of administration. Each participant also valued eight health states (randomly selected from a total of 15) that added the description of an AE to a migraine health state.

Results

A total of 400 participants completed interviews (200 general population [49.0% female; mean age = 43.6 years]; 200 migraine patients [74.5% female; mean age = 45.8 years]). In the general population sample, mean utilities of health states without aura were 0.79 with daily oral medication, 0.78 with one injection per month, and 0.72 with 31–39 injections once every 3 months. The greatest disutilities (i.e., decreases in utility) were for AEs associated with oral medications (e.g., − 0.060 [fatigue] and − 0.098 [brain fog]). Differences among health states followed the same pattern in the patient sample as in the general population sample.

Conclusions

Utilities estimated from the general population sample may be used to represent route of administration and AEs in cost-utility models. Results from the patient sample indicate that these treatment characteristics have an impact on patient preference.

Beta-blockers for the prevention of headache in adults, a systematic review and meta-analysis

BACKGROUND

Headaches are a common source of pain and suffering. The study's purpose was to assess beta-blockers efficacy in preventing migraine and tension-type headache.

METHODS

Cochrane Register of Controlled Trials; MEDLINE; EMBASE; ISI Web of Science, clinical trial registries, CNKI, Wanfang and CQVIP were searched through 21 August 2018, for randomized trials in which at least one comparison was a beta-blocker for the prevention of migraine or tension-type headache in adults. The primary outcome, headache frequency per month, was extracted in duplicate and pooled using random effects models.

DATA SYNTHESIS

This study included 108 randomized controlled trials, 50 placebo-controlled and 58 comparative effectiveness trials. Compared to placebo, propranolol reduced episodic migraine headaches by 1.5 headaches/month at 8 weeks (95% CI: -2.3 to -0.65) and was more likely to reduce headaches by 50% (RR: 1.4, 95% CI: 1.1-1.7). Trial Sequential Analysis (TSA) found that these outcomes were unlikely to be due to a Type I error. A network analysis suggested that beta-blocker's benefit for episodic migraines may be a class effect. Trials comparing beta-blockers to other interventions were largely single, underpowered trials. Propranolol was comparable to other medications known to be effective including flunarizine, topiramate and valproate. For chronic migraine, propranolol was more likely to reduce headaches by at least 50% (RR: 2.0, 95% CI: 1.0-4.3). There was only one trial of beta-blockers for tension-type headache.

CONCLUSIONS

There is high quality evidence that propranolol is better than placebo for episodic migraine headache. Other comparisons were underpowered, rated as low-quality based on only including single trials, making definitive conclusions about comparative effectiveness impossible. There were few trials examining beta-blocker effectiveness for chronic migraine or tension-type headache though there was limited evidence of benefit.

REGISTRATION

Prospero (ID: CRD42017050335).

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.

Erenumab: A First-in-Class Monoclonal Antibody for Migraine Prevention

Objective: To review the pharmacology, efficacy, and safety of the calcitonin gene-related peptide (CGRP) inhibitor erenumab for migraine preventive therapy. Data Sources: A MEDLINE/PubMed search (January 2000 to January 2019) was conducted using the keywords erenumab-aooe, erenumab, migraine, migraine prophylaxis, migraine prevention, and chronic migraine. Additional articles were identified by hand from references. Study Selection and Data Extraction: We included English-language articles (excluding poster presentations) evaluating erenumab pharmacology, efficacy, or safety in humans for migraine prevention. Data Synthesis: Erenumab is a CGRP inhibitor that inhibits vasodilation in response to acute migraines, which decreases pain perception during the migraine. Erenumab efficacy and safety has only been compared with placebo, but its reduction in monthly migraine days (MMDs) and medication response (≥50% reduction in MMDs) are comparable to current recommended off-label therapies for migraine prevention in short-term treatment studies. Additionally, erenumab is associated with low adverse event burden with no difference found compared with placebo per published clinical trials. Relevance to Patient Care and Clinical Practice: Erenumab is the first medication approved in the United States for the prevention of migraines in adults. No head-to-head data are available, but existing data suggest that erenumab is at least as effective as current off-label products and with reduced adverse effects. Conclusion: Erenumab is an effective once-monthly injectable agent for migraine prevention in patients with chronic or episodic migraine. It is also effective for patients who have previously failed migraine preventive therapy. Erenumab has a favorable adverse effect profile, which may improve patient adherence.

Treatment of migraine attacks and prevention of migraine: Guidelines by the German Migraine and Headache Society and the German Society of Neurology

In collaboration with some of the leading headache centres in Germany, Switzerland and Austria, we have established new guidelines for the treatment of migraine attacks and the prevention of migraine. A thorough literature research of the last 10 years has been the basis of the current recommendations. At the beginning, we present therapeutic novelties, followed by a summary of all recommendations. After an introduction, we cover topics like drug therapy and practical experience, non-effective medication, migraine prevention, interventional methods, non-medicational and psychological methods for prevention and therapies without proof of efficacy.

Benefit-risk assessment of erenumab and current migraine prophylactic treatments using the likelihood of being helped or harmed

Objective

This study evaluated the benefit-risk profile of erenumab relative to other therapies approved for migraine prophylaxis and available in the majority of European countries.

Methods

Trials were identified via a published systematic literature review updated to December 2017 using MEDLINE. Erenumab’s pivotal trials study reports were also included (NCT02066415, NCT02456740). From these sources, ≥ 50% responder rates and discontinuations due to adverse events were extracted to generate numbers needed to treat and harm and likelihood of being helped or harmed, a quantitative benefit-risk measure.

Results

Eleven articles (nine randomized clinical trials) met the inclusion/exclusion criteria. Low numbers needed to treat (range: 4–13) were observed for most treatments, while numbers needed to harm showed substantial differences (erenumab’s higher numbers needed to harm indicating better tolerability). In chronic and episodic migraine, likelihoods of being helped or harmed for erenumab 70 mg were 143 and 167, and 42 and 167 for erenumab 140 mg. Likelihoods of being helped or harmed in chronic migraine were 2 and 3 for topiramate (two studies) and 4 for onabotulinumtoxinA. In episodic migraine, likelihoods of being helped or harmed were 2 for topiramate and 2 for propranolol.

Conclusions

While all prophylactic treatments were more likely to help than harm (likelihood of being helped or harmed > 1), erenumab showed a likelihood of being helped or harmed of high magnitude, supporting its favorable benefit-risk profile across the entire migraine frequency spectrum, in contrast with other prophylactic treatments.

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.

Systematic review of the pharmacological agents that have been tested against spreading depolarizations

Spreading depolarization (SD) occurs alongside brain injuries and it can lead to neuronal damage. Therefore, pharmacological modulation of SD can constitute a therapeutic approach to reduce its detrimental effects and to improve the clinical outcome of patients. The major objective of this article was to produce a systematic review of all the drugs that have been tested against SD. Of the substances that have been examined, most have been shown to modulate certain SD characteristics. Only a few have succeeded in significantly inhibiting SD. We present a variety of strategies that have been proposed to overcome the notorious harmfulness and pharmacoresistance of SD. Information on clinically used anesthetic, sedative, hypnotic agents, anti-migraine drugs, anticonvulsants and various other substances have been compiled and reviewed with respect to the efficacy against SD, in order to answer the question of whether a drug at safe doses could be of therapeutic use against SD in humans.

Propranolol treatment prevents chronic central sensitization induced by repeated dural stimulation

Migraine is currently conceptualized as a chronic disease with episodic manifestations. In some patients, migraine attack frequency increases, leading to chronic migraine. Daily preventive therapy is initiated to decrease attack frequency. Propranolol, a first-line medication for migraine prophylaxis, reduces attack frequency in nearly 50% of patients receiving it. However, the mechanisms of its antimigraine action are unclear. We examined the effect of daily propranolol treatment (10 mg·kg per os, 8 days) in a rat model of recurrent activation of dural nociceptors (repeated infusion of an inflammatory soup (IS) on the dura through a cannula every 2-3 days). Propranolol does not abort IS-induced acute cephalic mechanical allodynia but blocks the development of a chronic cutaneous hypersensitivity upon repeated IS injections. Furthermore, propranolol prevents (1) the elevated touch-evoked Fos expression within the trigeminocervical complex, (2) enhanced both spontaneous activity, and evoked responses of second-order trigeminovascular neurons, (3) elevated touch-evoked rostral ventromedial medulla and locus coeruleus Fos expression and (4) diffuse noxious inhibitory controls impairment, induced by repeated IS injections. Our results suggest that propranolol exerts its prophylactic action, at least in part, by blocking the chronic sensitization of descending controls of pain, arising from the rostral ventromedial medulla and locus coeruleus, and in turn preventing the maintenance of a state of facilitated trigeminovascular transmission within the trigeminocervical complex. Assessing changes in these brain areas has the potential to elucidate the mechanisms for migraine transformation and to reveal novel biological and molecular targets for specific migraine-preventive therapies.

Glutamate and Its Receptors as Therapeutic Targets for Migraine

There is substantial evidence indicating a role for glutamate in migraine. Levels of glutamate are higher in the brain and possibly also in the peripheral circulation in migraine patients, particularly during attacks. Altered blood levels of kynurenines, endogenous modulators of glutamate receptors, have been reported in migraine patients. Population genetic studies implicate genes that are involved with glutamate signaling in migraine, and gene mutations responsible for familial hemiplegic migraine and other familial migraine syndromes may influence glutamate signaling. Animal studies indicate that glutamate plays a key role in pain transmission, central sensitization, and cortical spreading depression. Multiple therapies that target glutamate receptors including magnesium, topiramate, memantine, and ketamine have been reported to have efficacy in the treatment of migraine, although with the exception of topiramate, the evidence for the efficacy of these therapies is not strong. Also, because all of these therapies have other mechanisms of action, it is not possible to conclude that the efficacy of these drugs is entirely due to their effects on glutamate receptors. Further studies are needed to more clearly delineate the possible roles of glutamate and its specific receptor subtypes in migraine and to identify new ways of targeting glutamate for migraine therapy.

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.

Blocking CGRP in migraine patients - a review of pros and cons

Migraine is the most prevalent neurological disorder worldwide and it has immense socioeconomic impact. Currently, preventative treatment options for migraine include drugs developed for diseases other than migraine such as hypertension, depression and epilepsy. During the last decade, however, blocking calcitonin gene-related peptide (CGRP) has emerged as a possible mechanism for prevention of migraine attacks. CGRP has been shown to be released during migraine attacks and it may play a causative role in induction of migraine attacks. Here, we review the pros and cons of blocking CGRP in migraine patients. To date, two different classes of drugs blocking CGRP have been developed: small molecule CGRP receptor antagonists (gepants), and monoclonal antibodies, targeting either CGRP or the CGRP receptor. Several trials have been conducted to test the efficacy and safety of these drugs. In general, a superior efficacy compared to placebo has been shown, especially with regards to the antibodies. In addition, the efficacy is in line with other currently used prophylactic treatments. The drugs have also been well tolerated, except for some of the gepants, which induced a transient increase in transaminases. Thus, blocking CGRP in migraine patients is seemingly both efficient and well tolerated. However, CGRP and its receptor are abundantly present in both the vasculature, and in the peripheral and central nervous system, and are involved in several physiological processes. Therefore, blocking CGRP may pose a risk in subjects with comorbidities such as cardiovascular diseases. In addition, long-term effects are still unknown. Evidence from animal studies suggests that blocking CGRP may induce constipation, affect the homeostatic functions of the pituitary hormones or attenuate wound healing. However, these effects have so far not been reported in human studies. In conclusion, this review suggests that, based on current knowledge, the pros of blocking CGRP in migraine patients exceed the cons.

The effects of a multispecies probiotic on migraine and markers of intestinal permeability-results of a randomized placebo-controlled study

BACKGROUND/OBJECTIVES

Migraine, associated with several gastrointestinal disorders, may result from increased intestinal permeability, allowing endotoxins to enter the bloodstream. We tested whether probiotics could reduce migraine through an effect on intestinal permeability and inflammation.

SUBJECTS/METHODS

In total, 63 patients were randomly allocated to the probiotic (n=31) or the placebo group (n=32). Participants ingested a multispecies probiotic (5x10⁹ colony-forming units) or placebo daily for 12 weeks. Migraine was assessed with the Migraine Disability Assessment Scale (MIDAS), the Headache Disability Inventory (HDI) and headache diaries. At baseline and 12 weeks, intestinal permeability was measured with the urinary lactulose/mannitol test and fecal and serum zonulin; inflammation was measured from interleukin (IL) -6, IL-10, tumor necrosis factor-α and C-reactive protein in serum.

RESULTS

The MIDAS migraine intensity score significantly decreased in both groups (P<0.001) and the HDI score significantly decreased in the probiotic group (P=0.032) and borderline in the placebo group (P=0.053). In the probiotics group, patients had a median of 6 migraine days in the first month, 4 in the second month (P=0.002) and 5 in the last month, which was not significantly different from the 5, 4, and 4 days in the placebo group. A ⩾2day reduction in migraine days was seen in 12/31 patients in the probiotics group versus 7/29 in the placebo group (ns). Probiotic use did not significantly affect medication use, intestinal permeability or inflammation compared to placebo.

CONCLUSIONS

In this study, we could not confirm significant benefit from a multispecies probiotic compared to a placebo on the outcome parameters of migraine and intestinal integrity.

Unveiling the relative efficacy, safety and tolerability of prophylactic medications for migraine: pairwise and network-meta analysis

BACKGROUND

A large number patients struggle with migraine which is classified as a chronic disorder. The relative efficacy, safety and tolerability of prophylactic medications for migraine play a key role in managing this disease.

METHODS

We conducted an extensive literature search for popular prophylactic medications that are used for migraine patients. Pairwise meta-analysis and network meta-analysis (NMA) were carried out sequentially for determining the relative efficacy, safety and tolerability of prophylactic medications. Summary effect for migraine headache days, headache frequency, at least 50% reduction in headache attacks, all-adverse events, nausea, somnolence, dizziness, withdrawal and withdrawal due to adverse events were produced by synthesizing both direct and indirect evidence.

RESULTS

Patients with three interventions exhibited significantly less average migraine headache days compared with those treated by placebo (topiramate, propranolol, divalproex). Moreover, topiramate and valproate exhibited a significantly increased likelihood of at least 50% reduction in migraine headache attacks compared to placebo. Patients with topiramate and propranolol also exhibited significantly reduced headache frequency compared to those with placebo. On the other hand, patients with divalproex exhibited significantly higher risk of nausea compared to those with placebo, topiramate, propranolol, gabapentin and amitriptyline. Finally, divalproex was associated with an increased risk of withdrawal compared to placebo and propranolol.

CONCLUSIONS

Topiramate, propranolol and divalproex may be more efficacious than other prophylactic medications. Besides, the safety and tolerability of divalproex should be further verified by future studies.

General lack of use of placebo in prophylactic, randomised, controlled trials in adult migraine. A systematic review

Background

The Clinical Trials Subcommittee of the International Headache Society (IHS) recommends that a placebo arm is included in comparative randomised clinical trials (RCTs) of multiple prophylactic drugs due to the highly variable placebo response in migraine prophylaxis studies. The use of placebo control in such trials has not been systematically assessed.

Methods

We performed a systematic review of all comparative RCTs of prophylactic drug treatment of migraine published in English from 2002 to 2014. PubMed was searched using the Cochrane Highly Sensitive Search Strategy for identifying reports of RCTs.

Results

A placebo arm was used in <10% (three of 31) of prophylactic RCTs in migraine. In only 7.1% (two of 28) of the comparative RCTs without placebo was one drug superior to another drug. Thus in 26 RCTs, including one study requiring more than 75,000 patient days, no difference was identified across treatment arms and conclusions regarding drug superiority could not be drawn.

Conclusions

The majority of comparative, prophylactic migraine RCTs do not include a placebo arm. Failure to include a placebo arm may result in failure to demonstrate efficacy of potentially effective migraine-prophylactic agents. In order to benefit current and future patients, the current strong tendency to omit placebo-controls in these RCTs should be replaced by adherence to the guidelines of the IHS.

Chronic migraine: risk factors, mechanisms and treatment

Chronic migraine has a great detrimental influence on a patient's life, with a severe impact on socioeconomic functioning and quality of life. Chronic migraine affects 1-2% of the general population, and about 8% of patients with migraine; it usually develops from episodic migraine at an annual conversion rate of about 3%. The chronification is reversible: about 26% of patients with chronic migraine go into remission within 2 years of chronification. The most important modifiable risk factors for chronic migraine include overuse of acute migraine medication, ineffective acute treatment, obesity, depression and stressful life events. Moreover, age, female sex and low educational status increase the risk of chronic migraine. The pathophysiology of migraine chronification can be understood as a threshold problem: certain predisposing factors, combined with frequent headache pain, lower the threshold of migraine attacks, thereby increasing the risk of chronic migraine. Treatment options include oral medications, nerve blockade with local anaesthetics or corticoids, and neuromodulation. Well-defined diagnostic criteria are crucial for the identification of chronic migraine. The International Headache Society classification of chronic migraine was recently updated, and now allows co-diagnosis of chronic migraine and medication overuse headache. This Review provides an up-to-date overview of the classification of chronic migraine, basic mechanisms and risk factors of migraine chronification, and the currently established treatment options.

Cost-Effectiveness of Migraine Prevention: The Case of Topiramate in the UK

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

Clinical Features and Pharmacological Treatment of Migraine Patients Referred to Headache Specialists in Canada

We set out to examine selected clinical characteristics of migraine patients referred to neurologists specializing in headache in Canada, and to document their pharmacological therapy both before and after consultation with the neurologist. Demographic, clinical and pharmacotherapy data were collected at the time of consultation for 606 patients referred to five headache clinics and who were given a migraine diagnosis by the neurologist. Data were analysed as part of the Canadian Headache Outpatient Registry and Database (CHORD) Project. The mean age of the migraine patients was 39.7 years; and 82.5% were female. The majority of patients suffered severe impact from their headaches. Prior to consultation, 48.7% were taking a triptan; after consultation, 97.2% were on a triptan. Before consultation, 30.9% were on a prophylactic drug; after consultation, 70.4% were. 20.8% of patients were medication overusers. Of these medication overusers, 42.4% were overusing an opiate, usually in combination with other analgesics; 21.6% were overusing a triptan. Medication changes made by the neurologists at consultation included a large increase in the use of both triptans and prophylactic medications. Medication overuse, particularly opiate overuse, remains a significant problem in patients with migraine in Canada.

WITHDRAWN: Anticonvulsant drugs for migraine prophylaxis

July 2015: This review has been split and updated in a series of four new reviews (Linde 2013a; Linde 2013b; Linde 2013c; Linde 2013d). Readers are referred to those reviews for updated results. This review will not be updated.

May 2016: This review has now been withdrawn as it has been replaced by the four new titles listed above.

The editorial group responsible for this previously published document have withdrawn it from publication.

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.

The Use of Antiepileptics in Migraine Prophylaxis

BACKGROUND

Migraine is a chronic debilitating disorder. Selected antiepileptic drugs (AEDs) are proposed as preventives for migraine. Clinical efficacy and side effects of these AEDs are discussed.

SUMMARY OF REVIEW

The American Academy of Neurology and the American Society of Headache classify topiramate (TPM) and divalproex sodium (DVPX) as Level-A medications and recommend offering them to patients for migraine prophylaxis. Their mechanism(s) of actions remains not entirely known. Their recognized action as sodium channel blockers may affect the neural component of migraine pain. TPM or DVPX can be considered an obvious choice for those patients with a concomitant seizure disorder. Care must be taken to plan their treatment with their psychiatrist if a mood disorder is present. DVPX tends not to be prescribed as first/second choice due to its potential for weight gain and hepatotoxicity. TPM is generally first choice, but bears severe contraindications. Both medications require education on teratogenesis in childbearing women. Consideration of gabapentin, acetazolamide, leviteracetam, zonisamide, and carbamazipine may be given later as empiric options and in selected patients. Patients must be made aware that there is insufficient scientific support for their use in migraine.

CONCLUSIONS

Available AEDs to prophylactically treat migraine are few but of robust clinical efficacy. Special care needs to be exerted with respect to their side effects. Future research is needed for a better understanding of their mechanisms of action in migraine. Such research has the potential of providing some insight into the pathophysiology of migraine.

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.

Improvement of migraine symptoms with a proprietary supplement containing riboflavin, magnesium and Q10: a randomized, placebo-controlled, double-blind, multicenter trial

Background

Non-medical, non-pharmacological and pharmacological treatments are recommended for the prevention of migraine. The purpose of this randomized double-blind placebo controlled, multicenter trial was to evaluate the efficacy of a proprietary nutritional supplement containing a fixed combination of magnesium, riboflavin and Q10 as prophylactic treatment for migraine.

Methods

130 adult migraineurs (age 18 – 65 years) with ≥ three migraine attacks per month were randomized into two treatment groups: dietary supplementation or placebo in a double-blind fashion. The treatment period was 3 months following a 4 week baseline period without prophylactic treatment. Patients were assessed before randomization and at the end of the 3-month-treatment-phase for days with migraine, migraine pain, burden of disease (HIT-6) and subjective evaluation of efficacy.

Results

Migraine days per month declined from 6.2 days during the baseline period to 4.4 days at the end of the treatment with the supplement and from 6.2.days to 5.2 days in the placebo group (p = 0.23 compared to placebo). The intensity of migraine pain was significantly reduced in the supplement group compared to placebo (p = 0.03). The sum score of the HIT-6 questionnaire was reduced by 4.8 points from 61.9 to 57.1 compared to 2 points in the placebo-group (p = 0.01). The evaluation of efficacy by the patient was better in the supplementation group compared to placebo (p = 0.01).

Conclusions

Treatment with a proprietary supplement containing magnesium, riboflavin and Q10 (Migravent® in Germany, Dolovent® in USA) had an impact on migraine frequency which showed a trend towards statistical significance. Migraine symptoms and burden of disease, however, were statistically significantly reduced compared to placebo in patients with migraine attacks.

Cost-effectiveness analysis of interventions for migraine in four low- and middle-income countries

BACKGROUND

Evidence of the cost and effects of interventions for reducing the global burden of migraine remains scarce. Our objective was to estimate the population-level cost-effectiveness of evidence-based migraine interventions and their contributions towards reducing current burden in low- and middle-income countries.

METHODS

Using a standard WHO approach to cost-effectiveness analysis (CHOICE), we modelled core set intervention strategies for migraine, taking account of coverage and efficacy as well as non-adherence. The setting was primary health care including pharmacies. We modelled 26 intervention strategies implemented during 10 years. These included first-line acute and prophylactic drugs, and the expected consequences of adding consumer-education and provider-training. Total population-level costs and effectiveness (healthy life years [HLY] gained) were combined to form average and incremental cost-effectiveness ratios. We executed runs of the model for the general populations of China, India, Russia and Zambia.

RESULTS

Of the strategies considered, acute treatment of attacks with acetylsalicylic acid (ASA) was by far the most cost-effective and generated a HLY for less than US$ 100. Adding educational actions increased annual costs by 1-2 US cents per capita of the population. Cost-effectiveness ratios then became slightly less favourable but still less than US$ 100 per HLY gained for ASA. An incremental cost of > US$ 10,000 would have to be paid per extra HLY by adding a triptan in a stepped-care treatment paradigm. For prophylaxis, amitriptyline was more cost-effective than propranolol or topiramate.

CONCLUSIONS

Self-management with simple analgesics was by far the most cost-effective strategy for migraine treatment in low- and middle-income countries and represents a highly efficient use of health resources. Consumer education and provider training are expected to accelerate progress towards desired levels of coverage and adherence, cost relatively little to implement, and can therefore be considered also economically attractive. Evidence-based interventions for migraine should have as much a claim on scarce health resources as those for other chronic, non-communicable conditions that impose a significant burden on societies.