Frovatriptan for the acute treatment of migraine: a dose-finding study

Why is the therapeutic effect of acute antimigraine drugs delayed? A review of controlled trials and hypotheses about the delay of effect

In randomised controlled trials (RCTs) of oral drug treatment of migraine attacks, efficacy is evaluated after 2 hours. The effect of oral naratriptan 2.5 mg with a maximum blood concentration (Tmax ) at 2 hours increases from 2 to 4 hours in RCTs. To check whether such a delayed effect is also present for other oral antimigraine drugs, we hand-searched the literature for publications on RCTs reporting efficacy. Two triptans, 3 nonsteroidal anti-inflammatory drugs (NSAIDs), a triptan combined with an NSAID and a calcitonin gene-related peptide receptor antagonist were evaluated for their therapeutic gain with determination of time to maximum effect (Emax ). Emax was compared with known Tmax from pharmacokinetic studies to estimate the delay to pain-free. The delay in therapeutic gain varied from 1-2 hours for zolmitriptan 5 mg to 7 hours for naproxen 500 mg. An increase in effect from 2 to 4 hours was observed after eletriptan 40 mg, frovatriptan 2.5 mg and lasmiditan 200 mg, and after rizatriptan 10 mg (Tmax  = 1 h) from 1 to 2 hours. This strongly indicates a general delay of effect in oral antimigraine drugs. A review of 5 possible effects of triptans on the trigemino-vascular system did not yield a simple explanation for the delay. In addition, Emax for triptans probably depends partly on the rise in plasma levels and not only on its maximum. The most likely explanation for the delay in effect is that a complex antimigraine system with more than 1 site of action is involved.

Placebo Effects in Oral Triptan Trials: the Scientific and Ethical Rationale for Continued use of Placebo Controls

The aim of this study was to determine the characteristics of placebo effects in acute migraine treatment trials of triptans performed over 12 years and assess whether the use of placebo controls in trials of acute migraine treatment remains ethically and scientifically appropriate. We conducted a search for all controlled trials published in English between January 1991 and April 2002 in which adult subjects with migraine were randomly assigned to receive an oral triptan or placebo for the acute treatment of a migraine attack. Thirty-one trials met our criteria for inclusion. Placebo results for each study and pooled placebo results were calculated for the endpoints of headache response, pain-free response and adverse events. Heterogeneity was assessed using the Q statistic, and meta-regression using prespecified covariates was performed to investigate heterogeneity. The study results show a significant degree of heterogeneity. Efforts to explain heterogeneity with available data were not successful, with the exception of adverse event rates to placebo, for which study location (Europe vs. North America) partially explained differences in study results. AE rates were lower in European studies than in North American studies. Across all studies, the mean proportion of subjects who experienced a treatment response at two hours to placebo was 28.48 + 8.73% (range 17-50%). The mean proportion of subjects who experienced an adverse event to placebo was 23.40 + 14.05% (range 4.86-74%). The mean proportion of subjects who experienced a pain-free response to placebo at two hours was 6.08 + 4.43% (range 5-17%). Results of studies allowing use of prophylaxis did not differ significantly from those that did not allow prophylaxis. Placebo effects appear to be enhanced in studies involving children and adolescents. In contrast to an earlier, smaller review, our results do not suggest that randomization ratios influence placebo rates. We conclude that placebo effects in published trials of acute migraine medications are highly variable and often substantial. This variability in placebo response means that active control equivalence trials or the use of historical controls will not provide adequate proof of the safety or efficacy of new drugs, and will not differentiate between drugs that are active vs. placebo but of unknown efficacy relative to each other. The potential for approval of ineffective drugs, inability to compare results of studies performed in different locations, and poor characterization of the tolerability and safety profiles of new drugs represent a greater danger to migraineurs than does the limited-duration use of placebo in carefully monitored clinical trials of consenting subjects. These observations support the view that the inclusion of a placebo group remains of major scientific and ethical importance in trials of migraine medications.

The acute treatment of migraine in adults: the american headache society evidence assessment of migraine pharmacotherapies

The study aims to provide an updated assessment of the evidence for individual pharmacological therapies for acute migraine treatment. Pharmacological therapy is frequently required for acutely treating migraine attacks. The American Academy of Neurology Guidelines published in 2000 summarized the available evidence relating to the efficacy of acute migraine medications. This review, conducted by the members of the Guidelines Section of the American Headache Society, is an updated assessment of evidence for the migraine acute medications. A standardized literature search was performed to identify articles related to acute migraine treatment that were published between 1998 and 2013. The American Academy of Neurology Guidelines Development procedures were followed. Two authors reviewed each abstract resulting from the search and determined whether the full manuscript qualified for review. Two reviewers studied each qualifying full manuscript for its level of evidence. Level A evidence requires at least 2 Class I studies, and Level B evidence requires 1 Class I or 2 Class II studies. The specific medications - triptans (almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan [oral, nasal spray, injectable, transcutaneous patch], zolmitriptan [oral and nasal spray]) and dihydroergotamine (nasal spray, inhaler) are effective (Level A). Ergotamine and other forms of dihydroergotamine are probably effective (Level B). Effective nonspecific medications include acetaminophen, nonsteroidal anti-inflammatory drugs (aspirin, diclofenac, ibuprofen, and naproxen), opioids (butorphanol nasal spray), sumatriptan/naproxen, and the combination of acetaminophen/aspirin/caffeine (Level A). Ketoprofen, intravenous and intramuscular ketorolac, flurbiprofen, intravenous magnesium (in migraine with aura), and the combination of isometheptene compounds, codeine/acetaminophen and tramadol/acetaminophen are probably effective (Level B). The antiemetics prochlorperazine, droperidol, chlorpromazine, and metoclopramide are probably effective (Level B). There is inadequate evidence for butalbital and butalbital combinations, phenazone, intravenous tramadol, methadone, butorphanol or meperidine injections, intranasal lidocaine, and corticosteroids, including dexamethasone (Level C). Octreotide is probably not effective (Level B). There is inadequate evidence to refute the efficacy of ketorolac nasal spray, intravenous acetaminophen, chlorpromazine injection, and intravenous granisetron (Level C). There are many acute migraine treatments for which evidence supports efficacy. Clinicians must consider medication efficacy, potential side effects, and potential medication-related adverse events when prescribing acute medications for migraine. Although opioids, such as butorphanol, codeine/acetaminophen, and tramadol/acetaminophen, are probably effective, they are not recommended for regular use.

Pharmacokinetic evaluation of frovatriptan

INTRODUCTION

Migraine is the most common painful neurological disorder, affecting 13% of the general population. Triptans represent a powerful pharmacological tool in acute migraine treatment, however, a significant portion of treated patients cannot have access to this class due to possible adverse affects. Today, a total of seven triptan molecules are available, representing a commonly prescribed migraine treatment. Although there is a need of extensive use of triptans, only 25% of migraine patients are using triptans.

AREAS COVERED

This review includes triptans and evidence for the use of frovatriptan. A systematic approach is used to discuss the pharmacodynamic and pharmacokinetic aspects of frovatriptan, considering the emerging data on the clinical efficacy of frovatriptan in the treatment of migraine and cluster headaches. The data were obtained by searching the following key words in MEDLINE: pharmacokinetic, pharmacodynamic, triptans, frovatriptan, migraine, menstrual migraine, relatively to the period 1988 - 2011.

EXPERT OPINION

Frovatriptan has been developed in order to improve safety and efficacy of triptans. It shows a favorable tolerability and efficacy profile, limited to 24/48-h headache recurrence, when compared with other triptans. Preclinical data suggest that the pharmacokinetic profile of frovatriptan may differ from other available triptans. In fact, among triptans, frovatriptan showed the highest potency at the 5-HT1B receptor (8.2) and the longer half-life (26 h). These parameters determine the clinical properties of frovatriptan; in particular the lowest rate of headache recurrence in comparison with other triptans.

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

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

Frovatriptan is Effective and Well Tolerated in Korean Migraineurs: A Double-Blind, Randomized, Placebo-Controlled Trial

Background and Purpose

Frovatriptan is a selective 5-HT_1B/1D agonist with a long duration of action and a low incidence of side effects. Although several placebo-controlled trials have documented the clinical efficacy and safety of frovatriptan in adults with migraine, this drug has not previously been studied in Asian including Korean patients.

Methods

In this double-blind multicenter trial, 229 patients with migraine were randomized to receive frovatriptan 2.5 mg or placebo upon the occurrence of a moderate-to-severe migraine. The primary outcome was the 2-hour headache response rate.

Results

Frovatriptan significantly increased the 2-hour headache response rate compared with placebo (52.9% vs. 34.0%, p=0.004). The headache response rates at 4, 6, and 12 hours were significantly higher in the frovatriptan group than in the placebo group, as was the pain-free rate at 2 hours (19.0% vs. 5.7%, p=0.004), 4 hours (40.7% vs. 23.0%, p=0.006), and 6 hours (56.1% vs. 34.0%, p=0.002). The median time to a headache response was significantly shorter in the frovatriptan group than in the placebo group (2.00 hours vs. 3.50 hours, p<0.001). The use of rescue medications was more common in the placebo group (p=0.005). Chest tightness associated with triptan was infrequent (2.5%), mild, and transient.

Conclusions

These results demonstrate that 2.5-mg frovatriptan is effective and well tolerated in Korean migraineurs for acute treatment of migraine attacks.

The triptans

The migraine-specific triptans have revolutionized the treatment of migraine and are currently the drugs of choice to treat a migraine attack in progress. Over the past 15 years, triptans were released in rapid succession, with each one demonstrating some specific pharmacokinetic properties that may be translated into clinical advantages. Triptans share many similarities, but also have important differences from one another. Accordingly, herein we discuss the class of the triptans. We first define the trigeminovascular system and its importance in migraine pain, then discuss the mechanism of action of the triptans and contrast the evidence supporting the use of different triptans. We close with our view of the future and hopes for the next generation of antimigraine therapies.

Marketed oral triptans in the acute treatment of migraine: a systematic review on efficacy and tolerability

BACKGROUND

In the current literature, there is neither a reported systematic review comparing the efficacy of triptans at 30 minutes and 1 hour after the migraine treatment, nor data related to efficacy of new marketed triptans.

OBJECTIVE

The main objective of this analysis was to compare the efficacy and tolerability of currently marketed oral, non-reencapsulated triptan formulations vs placebo in the treatment of moderate-to-severe migraine attacks.

METHODS

A systematic review of double-blind, randomized clinical trials reporting data after a single migraine attack was conducted. Efficacy results are shown using relative risk ratios with 95% confidence intervals. A sensitivity analysis was also conducted.

RESULTS

After reviewing 221 publications, 38 studies were included. All marketed triptans provided significant relief and/or absence of pain at 2 hours, and relief at 1 hour when compared with placebo. After 30 minutes, fast-dissolving sumatriptan 50 and 100 mg, sumatriptan 50 mg, and rizatriptan 10 mg showed significant relief when compared to placebo, whereas the fast-dissolving formulation of sumatriptan 100 mg was the only oral triptan that was superior to placebo in meeting the pain-free endpoint. On the other hand, fast-dissolving sumatriptan 50 and 100 mg and eletriptan 40 mg showed a lower rate of recurrence than placebo, whereas rizatriptan 10 mg was the only triptan with a recurrence rate greater than that of placebo. Adverse events associated with treatment with tablet formulations of sumatriptan and zolmitriptan were significantly more frequent than those of the placebo group. The inclusion of trials with reencapsulated triptans in the analysis introduced minor specific changes in these results.

CONCLUSION

This analysis updates the comparative data available for the 7 currently marketed oral triptans and clearly demonstrates their efficacy when compared to placebo, even with stricter endpoints, such as efficacy at 30 minutes. No triptan exhibited better tolerability than placebo. Results are diverse, depending on the triptan, which probably is a reflection of heterogeneous pharmacokinetics.

Pain Characteristics of the Acute Migraine Attack

OBJECTIVES

This study describes the pain characteristics of the acute migraine attack, including time of onset, time to peak, duration, intensity, quality, aggravation by activity, as well as recurrence frequency and time to recurrence, in a tertiary care practice.

BACKGROUND

The literature documenting the characteristics of the pain of the acute attack of migraine is sparse.

METHODS

A total of 1,283 migraine patients (ICHD 1.1, 1.2, 1.5.1, and ICHD 1.6 [total migraine population]) were evaluated at first visit. Headache character (throbbing, aching, pressure, stabbing scaled grade 0 to 3; 0 = none; 1 = mild; 2 = moderate; 3 = severe), intensity (for average, minimum, and maximum intensity headaches, scaled 0 to 10), lifetime duration, frequency per month, duration in minutes (for average, minimum, maximum duration headaches), time of onset of headache (morning, afternoon, evening, night, anytime), aggravation of headache with activity (scaled 0 to 3), percentage recurrence, time to recurrence, were recorded. Patients were stratified into different groups; ICHD 1.1, 1.2, and 1.5.1 (migraine) ICHD 1.1 and 1.2 (episodic migraine), ICHD 1.5.1 (chronic migraine), and ICHD 1.6 (probable migraine). Patients with unremitting daily headache were excluded.

RESULTS

DEMOGRAPHICS

A total of 84.3% patients were female, and the mean age was 37.7, ranging from 13.0 to 80.5 years. Eight hundred seventy-four patients were classified as ICHD 1.1, 1.2, and 1.5.1 (migraine), 524 with ICHD 1.1 and 1.2 (episodic migraine), 350 with ICHD 1.5.1 (chronic migraine), and 409 with ICHD 1.6 (probable migraine).

STUDY RESULTS

Time of onset of headache was mostly in the morning in 18.7%, afternoon 13.5%, evening 4.0%, during night 9.4%, and "anytime" 54.3%, with minor differences seen in different headache types, gender, presence of aura, and headache frequency. The median time to peak of the headache was greater in migraine than probable migraine (90 minutes vs. 60 minutes; P < .01). Headache duration medians were reported as minimum of 12 hours, maximum of 48 hours with an average of 24 hours, females being greater than males in average headache (24.0 vs. 12.0; P < .01), minimum (24.0 vs. 8; P < .05), and maximum (48.0 vs. 24.0; P < .01). Only the minimum duration differed between migraine and atypical migraine (12.0 vs. 4.0; P < .01). Headache intensity medians were as follows: average intensity 7/10, minimum 4/10, and maximum 10/10, with no differences in migraine versus probable migraine, gender, or headache frequency. Headache intensity median was consistently greater in migraine episodic than chronic migraine (average 8.0 vs. 6.5, minimum 4.5 vs. 3.0, maximum 10.0 vs. 9.0, all P < .05). Headache character (greater than grade 1) was throbbing (73.5%), aching (73.8%), pressure (75.4%), and stabbing (42.6%) with significantly more throbbing in migraine than in probable migraine (73.5% vs. 63.2%; P < .01) and more aching in chronic than in episodic migraine (65.4% vs. 63.1%; P < .05). Headache increased by activity was present in 90.2% of patients, grade 1 in 13.8%, grade 2 in 30.8%, and grade 3 in 45.5% of patients. The presence of activity aggravating headache was more likely to be associated with headache triggers, maximum headache severity, longer time to 50% reduction of headache, and longer time to absent headache with triptans, and more headache-associated symptoms, and longer postdrome duration (all P < .05). Recurrence rate was 43.8% with the median time to recurrence being 8 hours. Significantly less recurrence occurred with episodic than chronic migraine (30.0% vs. 50.0%; P < .01).

CONCLUSIONS

This study provides an in-depth description of pain features in the acute migraine attack. It was found that a significant number of patients need to be provided with the means of treating headache rapidly in at least some of their headaches and that headache recurrence needs to be addressed in a large number of patients.

Efficacy and tolerability of frovatriptan in acute migraine treatment: systematic review of randomized controlled trials

OBJECTIVE

To evaluate the efficacy and tolerability of frovatriptan in acute migraine treatment.

METHODS

Systematic review and meta-analysis of randomized controlled trials. Clinical trials of frovatriptan were systematically identified through electronic searches and historical searches up until February 2005. Studies were included if they were (i) double-blind, randomized, placebo controlled trials that evaluated frovatriptan 2.5 mg in acute migraine treatment and (ii) reporting the efficacy data in terms of pain-free, headache response, headache recurrence, or relief of migraine-associated symptoms. Two authors extracted data independently. Disagreements were resolved through discussion. The efficacy was estimated using risk ratio (RR), risk difference, and number needed to treat together with 95% confidence intervals.

RESULTS

Five trials involving a total of 2,866 patients were included. Frovatriptan 2.5 mg was more effective than placebo in rendering patient pain-free (RR 3.70, 95% CI 2.59-5.29, P < 0.0001 at 2 h and 2.67, 95% CI 2.21-3.22, P < 0.0001 at 4 h post-dose). It was also superior to placebo in reducing headache severity. The pooled RR was 1.66 (95% CI 1.48-1.88, P < 0.0001) and 1.83 (95% CI 1.66-2.00, P < 0.0001), respectively, at 2 and 4 h after treatment. In those whose headache was relieved at 4 h, the risk of headache recurrence within 24 h was reduced by 26% with frovatriptan (RR 0.74, 95% CI 0.59-0.93, P = 0.009). Frovatriptan was also superior to placebo in improving symptoms associated with migraine. At 2 h after dosing, frovatriptan reduced the risk of nausea by 14% (95% CI 6-20%, P = 0.0005), photophobia 17% (95% CI 12-22%, P < 0.0001), and phonophobia 14% (95% CI 17-20%, P < 0.0001). The corresponding numbers at 4 h after dosing were 37% (95% CI 30-43%, P < 0.0001), 34% (95% CI 29-39%, P < 0.0001) and 30% (95% CI 23-36%, P < 0.0001), respectively. Frovatriptan caused more adverse events than did placebo (RR 1.31, 95% CI 1.07-1.62, P = 0.01).

CONCLUSION

The available evidence suggests that frovatriptan is more effective but may cause more adverse events than placebo in the treatment of acute moderate to severe migraine. It is effective in providing pain relief and reducing the risk of recurrence. However, its effectiveness relative to other more established agents needs to be better defined by appropriate head to head trials.

Cost effectiveness of oral triptan therapy: a trans-national comparison based on a meta-analysis of randomised controlled trials

OBJECTIVE

The objective of this study was to appraise the relative cost effectiveness of oral triptan therapy in the management of acute migraine, comparing the results obtained using drug cost data from six different countries, USA, UK, Canada, Germany, Italy and The Netherlands.

METHOD

A meta-analysis of randomised placebo controlled trials of single dose oral triptans was carried out in order to calculate aggregate Numbers Needed to Treat (NNT) for each triptan and dose. Cost effectiveness ratios were then derived for each treatment by applying mean drug acquisition costs for each country to these NNTs. Using a graphical plot for each country, incremental cost effectiveness comparisons were then made versus sumatriptan 100 mg, the most commonly used oral triptan.

RESULTS

When analysed in terms of 2-h pain one country to another. When compared to free outcomes, rizatriptan 10 mg and eletriptan 40 and 80 mg were the most effective oral triptans. Rizatriptan 10mg has the most advantageous absolute cost effectiveness ratio in all six countries studied, although levels of statistical significance compared to other agents varied from sumatriptan 100mg, rizatriptan 10 mg and eletriptan 40 mg are most consistently the cost effective treatment choices, both being cost dominant in five out of six countries studied.

CONCLUSIONS

There are systematic differences in triptan efficacy that have an impact on treatment choice. Differences in pricing structure between countries mean that hierarchies of cost effectiveness will vary. Country-specific data should therefore be examined before defining treatment strategies.

Migraine headache recurrence: relationship to clinical, pharmacological, and pharmacokinetic properties of triptans

BACKGROUND AND OBJECTIVES

Triptan use is associated with headache recurrence, and this has been cited as an important reason for patient dissatisfaction with the treatment. The mechanism by which recurrence occurs is not clear, and the incidence of recurrence varies with the triptan used. In order to explore the pharmacological and physiological interaction of triptans and migraine headache recurrence further, some specific clinical, pharmacological, and pharmacokinetic factors that might influence migraine recurrence were evaluated in a review of the major efficacy data for the drugs in the triptan class. These factors were 5-HT1B and 5-HT1D receptor activities, the pharmacokinetic elimination half-life of each triptan, and the clinical efficacy of each compound, determined by the proportion of patients with headache relief and the therapeutic gain over placebo.

METHODS

Clinical data were derived from 31 triptan, placebo-controlled, major efficacy studies used in a previous meta-analysis. The mean recurrence rate, mean headache response, and therapeutic gain were calculated using the results from the individual clinical studies. Mean headache response and therapeutic gain were calculated at the time point used to define recurrence in each study. Data for binding affinity and potency were taken from a direct-comparison in vitro pharmacology study, and the elimination half-life quoted in the data sheet for each triptan was used. Rank correlation with recurrence rate was performed for each of the test parameters.

RESULTS

Mean headache recurrence rates ranged from 17% for frovatriptan 2.5 mg to 40% for rizatriptan. Elimination half-life and recurrence were inversely correlated (r = -1.0, P =.0016). There was also a significant inverse correlation between 5-HT1B receptor potency and recurrence (r = -0.68, P =.034), but 5-HT1D receptor potency was not correlated with recurrence (r = -0.20, P =.54). In addition, the binding affinities for the 5-HT1B and 5-HT1D receptors were not correlated to headache recurrence. Importantly, it also was demonstrated that initial clinical efficacy was not correlated to headache recurrence. The correlation coefficient for headache response was 0.18 (P =.53) and for therapeutic gain, -0.11 (P =.71).

CONCLUSION

The incidence of migraine headache recurrence varies between drugs in the triptan class. Migraine recurrence does not appear to be related to initial clinical efficacy, but is influenced by the pharmacological and pharmacokinetic properties of the individual triptans. The triptans with longer half-lives and greater 5-HT1B receptor potency had the lowest rates of headache recurrence.

Frovatriptan: a review

Frovatriptan is a potent 5-HT(1B/1D) receptor agonist and has the highest 5-HT(1B) potency in the triptan class. preclinical pharmacology studies demonstrated that frovatriptan is apparently cerebro-selective. In clinical pharmacology studies, frovatriptan was shown to have a long-terminal elimination half-life of 26 h and to be well-tolerated across a broad dose range of 1-100 mg. Frovatriptan has no inhibiting or inducing effects on cytochrome P450 isoenzymes and is only slightly bound to plasma proteins; thus it has a low potential for drug interactions. No dosage adjustments are necessary based on age or renal or hepatic impairment. Efficacy studies show significantly higher response rates compared with placebo and the lowest reported range of headache recurrence rates in the triptan class. Safety studies show a side effect profile similar to placebo. The combination of cerebro-selectivity, long half-life, reliable efficacy, low recurrence rates and good tolerability make frovatriptan a valuable new choice for acute treatment of migraine. Frovatriptan may be particularly well suited to patients with migraine of long duration, those prone to recurrence and those troubled by "triptan-type" side effects.