Naratriptan is effective and well tolerated in the acute treatment of migraine. Results of a double-blind, placebo-controlled, parallel-group study. Naratriptan S2WA3001 Study Group

Evidence-based guidelines for the pharmacological treatment of migraine

We here present evidence-based guidelines for the pharmacological treatment of migraine. These guidelines, created by the Italian Society for the Study of Headache and the International Headache Society, aim to offer clear, actionable recommendations to healthcare professionals. They incorporate evidence-based recommendations from randomized controlled trials and expert-based opinions. The guidelines follow the Grading of Recommendations, Assessment, Development and Evaluation approach for assessing the quality of evidence. The guideline development involved a systematic review of literature across multiple databases, adherence to Cochrane review methods, and a structured framework for data extraction and interpretation. Although the guidelines provide a robust foundation for migraine treatment, they also highlight gaps in current research, such as the paucity of head-to-head drug comparisons and the need for long-term outcome studies. These guidelines serve as a resource to standardize migraine treatment and promote high-quality care across different healthcare settings.

Comparison between metamizole and triptans for migraine treatment: a systematic review and network meta-analysis

Objective The aim of this systematic review was to evaluate the efficacy of metamizole and triptans for the treatment of migraine. MethodsRandomized controlled trials including people who received metamizole or triptan by multiple routes of administration and at all doses as treatment compared to subjects who received another treatment or placebo were included in the systematic review. The primary outcomes were freedom from pain at 2 hours; pain relief at 2 hours; sustained headache response at 24 hours; sustained freedom from pain at 24 hours. The statistical analysis of all interventions of interest were based on random effect models compared through a network meta-analysis. Results 209 studies meeting the inclusion and exclusion criteria were analyzed. Of these, 130 had data that could be analyzed statistically. Only 3.0% provided enough information and were judged to have a low overall risk of bias for all categories evaluated; approximately 50% of the studies presented a low risk of selection bias. More than 75% of the studies presented a low risk of performance bias, and around 75% showed a low risk of detection and attrition bias. ConclusionThere is no evidence of a difference between dipyrone and any triptan for pain freedom after 2 hours of medication. Our study suggests that metamizole may be equally effective as triptans in acute migraine treatment.

Acute Care and Treatment of Migraine

OBJECTIVE

Migraine is a chronic neurological disease involving the brain and its vasculature, typically characterized by recurrent attacks of moderate or severe throbbing headache, accompanied by sensitivity to light and sound, and associated with nausea, vomiting, and inability to move due to worsening of pain. About 30% of migraineurs have some type of aura, most often visual. Migraine attacks, if untreated or suboptimally treated, usually result in significant disability, requiring bed rest and resulting in poor quality of life. Increased frequency of attacks and overuse of acute care medication are significant risks for chronification, resulting in the transformation of episodic migraine into chronic migraine. We aim to review most acute care treatments for migraine.

METHODS

Current treatment options for migraine attacks were reviewed from the selected literature and combined with our clinical experience.

RESULTS

Current acute treatment options for migraine attacks include over-the-counter analgesics, at times combined with caffeine, nonsteroidal anti-inflammatory medications, opioids, and migraine-specific medications such as triptans and ergots. In the near future, we will probably have 3 gepants (small-molecule calcitonin gene-related peptide [CGRP] receptor antagonists). The first one was just approved in the United States. A ditan acting as a stimulator of 5-HT1F receptors, was also just approved by the FDA. Stimulation of the trigeminal, vagal, occipital, and even upper arm peripheral nerves through electrical nerve stimulation devices and magnetic stimulation devices are available as alternative, nondrug treatment options. Several devices have already been FDA-allowed for treatment in the United States and/or approved elsewhere, and others will follow soon. Behavioral medicine techniques such as biofeedback training and mindfulness have been available for some time and are often helpful.

CONCLUSION

A wide variety of acute care options to treat migraine are available, and others will soon be and will herein be described in further detail. Some medications have been approved by regulatory authorities in countries other than the United States, and some devices have been given a CE Mark in Europe.

Onset of action in placebo-controlled migraine attacks trials: A literature review and recommendation

BACKGROUND

Migraine patients want acute treatment to provide complete relief of the migraine attack within 30 minutes. Traditionally, "speed of onset of effect" is evaluated by estimating the time-point for first statistical separation of drug and placebo. The estimated onset of effect can be a few percent difference of patients being pain free in very large randomised, controlled trials. This difference, however, can be clinically irrelevant.

METHODS

Placebo-controlled randomised, controlled trials with pain freedom results from 30 min to 2-4 hours were retrieved from the literature. For each time-point, the therapeutic gain (drug minus placebo) (TG) was calculated. Therapeutic gain for being pain free of 5% was chosen for the definition of "onset of action", since this is approximately 1/3 of the 16% TG and 1/4 of 21% of TG for sumatriptan 50 mg and 100 mg, respectively.

RESULTS

A total of 22 time-effect curves based on randomised, controlled trials were analysed. Based on the "onset of action" of 5% pain freedom, the evaluated drugs and administration forms can be classified as follows: i) Early time to onset, ≤30 min (three randomised, controlled trials); ii) medium time to onset, 60 min (nine randomised, controlled trials); iii) delayed time to onset, 90-120 min (10 randomised, controlled trials).

CONCLUSION

Only three non-oral administration forms with a triptan (subcutaneous sumatriptan and nasal zolmitriptan) resulted in an "onset of action" at ≥30 min; in the future, early onset of action should be a priority in the development of new drugs or new administration-forms for the treatment of acute migraine attacks.

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.

Onset of Efficacy Following Oral Treatment With Lasmiditan for the Acute Treatment of Migraine: Integrated Results From 2 Randomized Double-Blind Placebo-Controlled Phase 3 Clinical Studies

Objective

To expand on available information on the efficacy of oral lasmiditan for the acute treatment of migraine with particular focus on the timing of the effect and on its impact on migraine‐associated symptoms.

Background

Lasmiditan is a novel selective 5‐hydroxytryptamine 1F receptor agonist that lacks vasoconstrictive activity. In 2 phase 3 studies, SAMURAI and SPARTAN, lasmiditan met primary and key secondary efficacy endpoints at 2 hours following initial dose.

Methods

Integrated analyses were completed from 2 phase 3 clinical trials, SPARTAN and SAMURAI. Baseline data and data collected every 30 minutes up to 2 hours after taking lasmiditan (50, 100, or 200 mg) or placebo were analyzed to determine the onset of efficacy. A total of 5236 patients were randomized to be treated with placebo (N = 1493), lasmiditan 50 mg (N = 750), lasmiditan 100 mg (N = 1498), or lasmiditan 200 mg (N = 1495). Data were analyzed to determine the onset of improvement for the following efficacy measures: pain freedom, most bothersome symptom freedom, pain relief, freedom from associated individual symptoms (photophobia, phonophobia, or nausea), total migraine freedom (defined as pain freedom and freedom from associated symptoms), and freedom from migraine‐related functional disability. Time to meaningful headache relief and time to first become pain free were also analyzed.

Results

Significantly higher rates of pain freedom (100 mg, 10.0%, P = .012; 200 mg, 15.5%, P < .001; Placebo, 7.0%) and total migraine freedom (100 mg, 8.9%, P = .017; 200 mg, 12.4%, P < .001; Placebo, 6.1%) were achieved starting at 60 minutes in 100‐ and 200‐mg lasmiditan‐treated groups compared with placebo group. Rates of freedom from most bothersome symptom (100 mg, 11.1%, P = .015; 200 mg, 13.0%, P < .001; Placebo, 7.9%), and pain relief (100 mg, 17.5%, P = .007; 200 mg, 19.1%, P < .001; Placebo, 13.4%) were significantly higher starting as early as 30 minutes in lasmiditan 100‐ and 200‐mg lasmiditan‐treated groups. A significantly higher percentage of patients in the 200‐mg lasmiditan‐treated group achieved freedom from photophobia (13.7%, P = .005; Placebo, 9.2%) and phonophobia (17.4%, P = .042; Placebo, 13.4%) starting at 30 minutes. A significantly greater proportion of patients in the 200‐mg lasmiditan‐treated group achieved freedom from migraine‐related functional disability starting at 60 minutes (16.4%, P < .001; Placebo, 11.1%). All efficacy measures, except for freedom from nausea, were statistically significant after lasmiditan treatment (50, 100, or 200 mg) compared with placebo at 90 and 120 minutes. Finally, patients taking lasmiditan had a higher likelihood of achieving meaningful headache relief and becoming headache pain free within 24 hours compared with those taking placebo (P < .001).

Conclusions

Patients treated with lasmiditan for a migraine attack reported an earlier onset of efficacy compared with those treated with placebo. Some of the efficacy measures such as pain relief demonstrated improvement as early as the first assessment at 30 minutes after 100‐ or 200‐mg lasmiditan treatment.

Comparative tolerability of treatments for acute migraine: A network meta-analysis

Introduction Migraine headache is a neurological disorder whose attacks are associated with nausea, vomiting, photophobia and phonophobia. Treatments for migraine aim to either prevent attacks before they have started or relieve attacks (abort) after onset of symptoms and range from complementary therapies to pharmacological interventions. A number of treatment-related adverse events such as somnolence, fatigue, and chest discomfort have previously been reported in association with triptans. The comparative tolerability of available agents for the abortive treatment of migraine attacks has not yet been systematically reviewed and quantified. Methods We performed a systematic literature review and Bayesian network meta-analysis for comparative tolerability of treatments for migraine. The literature search targeted all randomized controlled trials evaluating oral abortive treatments for acute migraine over a range of available doses in adults. The primary outcomes of interest were any adverse event, treatment-related adverse events, and serious adverse events. Secondary outcomes were fatigue, dizziness, chest discomfort, somnolence, nausea, and vomiting. Results Our search yielded 141 trials covering 15 distinct treatments. Of the triptans, sumatriptan, eletriptan, rizatriptan, zolmitriptan, and the combination treatment of sumatriptan and naproxen were associated with a statistically significant increase in odds of any adverse event or a treatment-related adverse event occurring compared with placebo. Of the non-triptans, only acetaminophen was associated with a statistically significant increase in odds of an adverse event occurring when compared with placebo. Overall, triptans were not associated with increased odds of serious adverse events occurring and the same was the case for non-triptans. For the secondary outcomes, with the exception of vomiting, all triptans except for almotriptan and frovatriptan were significantly associated with increased risk for all outcomes. Almotriptan was significantly associated with an increased risk of vomiting, whereas all other triptans yielded non-significant lower odds compared with placebo. Generally, the non-triptans were not associated with decreased tolerability for the secondary outcomes. Discussion In summary, triptans were associated with higher odds of any adverse event or a treatment-related adverse event occurring when compared to placebo and non-triptans. Non-significant results for non-triptans indicate that these treatments are comparable with one another and placebo regarding tolerability outcomes.

Published and not fully published double-blind, randomised, controlled trials with oral naratriptan in the treatment of migraine: a review based on the GSK Trial Register

Naratriptan 2.5 mg is now an over-the-counter drug in Germany. This should increase the interest in drug. The GSK Trial Register was searched for published and unpublished double-blind, randomised, controlled trials (RCTs) concerning the use of naratriptan in migraine. Only 7 of 17 RCTs are published in full. Naratriptan 2.5 mg is superior to placebo for acute migraine treatment in 6 RCTs, but inferior to sumatriptan 100 mg and rizatriptan 10 mg in one RCT each. This dose of naratriptan has no more adverse events than placebo. Naratriptan 1 mg b.i.d. has some effect in the short-term prophylactic treatment of menstruation-associated migraine in 3 RCTs. In 2 RCTs, naratriptan 2.5 mg was equivalent to naproxen sodium 375 mg for migraine-related quality of life. Naratriptan 2.5 mg (34% preference) was superior to naproxen sodium 500 mg (25% preference). Naratriptan 2.5 mg is better than placebo in the acute treatment of migraine. The adverse effect profile of naratriptan 2.5 mg is similar to that of placebo. The efficacy of naratriptan 2.5 mg versus NSAIDs is not sufficiently investigated. Naratriptan, when available OTC is a reasonable second or third choice on the step care ladder in the acute treatment of migraine.

Self-medication of migraine and tension-type headache: summary of the evidence-based recommendations of the Deutsche Migräne und Kopfschmerzgesellschaft (DMKG), the Deutsche Gesellschaft für Neurologie (DGN), the Österreichische Kopfschmerzgesellschaft (ÖKSG) and the Schweizerische Kopfwehgesellschaft (SKG)

The current evidence-based guideline on self-medication in migraine and tension-type headache of the German, Austrian and Swiss headache societies and the German Society of Neurology is addressed to physicians engaged in primary care as well as pharmacists and patients. The guideline is especially concerned with the description of the methodology used, the selection process of the literature used and which evidence the recommendations are based upon. The following recommendations about self-medication in migraine attacks can be made: The efficacy of the fixed-dose combination of acetaminophen, acetylsalicylic acid and caffeine and the monotherapies with ibuprofen or naratriptan or acetaminophen or phenazone are scientifically proven and recommended as first-line therapy. None of the substances used in self-medication in migraine prophylaxis can be seen as effective. Concerning the self-medication in tension-type headache, the following therapies can be recommended as first-line therapy: the fixed-dose combination of acetaminophen, acetylsalicylic acid and caffeine as well as the fixed combination of acetaminophen and caffeine as well as the monotherapies with ibuprofen or acetylsalicylic acid or diclofenac. The four scientific societies hope that this guideline will help to improve the treatment of headaches which largely is initiated by the patients themselves without any consultation with their physicians.

Acute treatment of migraine

Acute treatment of migraine has benefited first from major advances in pharmacological science followed in short order, sometimes preceded, by an improved understanding of pathogenesis, especially of headache. This chapter reviews the mechanisms of migraine that provide an understanding of the pharmacology and therapeutic targets for acute migraine medications. General clinical approaches to acute therapy are reviewed, and indices of acceptable acute therapeutic outcomes are discussed. Currently the serotonin (5-HT) 1B/1D agonist group of drugs, triptans, forms the mainstay of acute therapeutic regimens. Other approaches to acute treatment such as simple analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), ergots, and combination medications are reviewed. Finally, the newest acute treatments that are currently exploratory or under clinical investigation are discussed.

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.

Parenteral vs. oral sumatriptan and naratriptan: plasma levels and efficacy in migraine. a comment

The clinical efficacy in migraine was compared for oral and subcutaneous sumatriptan and naratriptan. Doses of the two administration forms were chosen as resulting in comparable blood concentrations. Subcutaneous administrations of the drugs were superior for efficacy than the oral forms. This most likely due to a quicker rise in blood concentrations after subcutaneous injections.. In designing new therapies for migraine one should aim at a quick absorption of the drug, which will probably result in an increased efficacy.

Efficacy and tolerability of naratriptan for short-term prevention of menstrually related migraine: data from two randomized, double-blind, placebo-controlled studies

BACKGROUND

In a pilot study, naratriptan was significantly more effective than placebo in preventing menstrually related migraine (MRM) when given as 1 mg twice daily for 5 days beginning 2 days before the predicted onset of MRM for up to 4 menstrual cycles.

OBJECTIVE

To evaluate the efficacy and tolerability of naratriptan for short-term prevention of MRM in 2 large, identically designed, randomized, double-blind, placebo-controlled, parallel-group studies.

METHODS

MRM was defined as any migraine beginning during the perimenstrual period (PMP). By definition, the PMP consisted of Days -2, -1, 1, 2, 3, and 4, with Day 1 being the first day of menstrual flow. Adult women were eligible if they reported a history of MRM, had regular menstrual cycles, and could predict within 2 days both the onset of menstrual flow and MRM. The studies comprised a baseline phase and a treatment phase. During the baseline phase, patients prophylactically treated their first PMP after the screening visit with single-blind placebo. Patients who documented an MRM while receiving placebo were eligible for the treatment phase. During the treatment phase, patients were randomized to receive either naratriptan 1 mg twice daily or placebo beginning 3 days before the predicted onset of MRM for a total of 6 days for 4 PMPs or 6 months, whichever occurred sooner. The primary efficacy endpoint was the mean percentage of treated PMPs without MRM per patient. Secondary efficacy endpoints included the percentage of patients who were free of MRM during all treated PMPs, the median number of days with MRM over 4 PMPs, and patient satisfaction. Safety and tolerability measures included adverse events, standard clinical laboratory tests, and vital signs.

RESULTS

The intent-to-treat population was 287 in Study 1 (149 in the naratriptan group and 138 in the placebo group) and 346 in Study 2 (173 in each treatment group). Approximately 20% of randomized patients in each treatment group in Study 1 and 10% in each treatment group in Study 2 withdrew prematurely from the studies over the 4-month treatment period. The mean percentage of PMPs without MRM per patient was 38% and 34% among naratriptan-treated patients treating at least 1 PMP compared with 29% and 24% among placebo-treated patients in each respective study (P < .05 naratriptan vs placebo for both studies). Efficacy of naratriptan did not vary as a function of age, use of oral contraceptives, or use of migraine prophylaxis. More patients who had received naratriptan reported attacks posttreatment compared to patients who had received placebo. Among patients treating at least 1 PMP, the percentage of patients with no MRM in any treated PMP was significantly (P < .05) higher in the naratriptan group (11%; 19/173) than the placebo group (3%; 6 of 173) in Study 2. There were no differences in the percentages of patients with no MRM in any treated PMP in Study 1. The number of MRM days per patient across 4 PMPs was significantly lower in the naratriptan group than in the placebo group in both studies (median 5.0 days vs 6.5 days in Study 1 [P= .005] and 5.3 days vs 6.0 days in Study 2 [P= .018]). Significantly more patients receiving naratriptan were satisfied with the ability of naratriptan to control MRM either by preventing their occurrence or reducing their severity or duration compared with patients receiving placebo. No single drug-related adverse event was reported by more than 2% of patients in a treatment group in either study, and no serious drug-related adverse events were reported.

CONCLUSIONS

Naratriptan 1 mg twice daily for 6 days per month is effective and well tolerated when used for short-term prevention of MRM. More patients receiving naratriptan than placebo were satisfied with treatment. The observed increase in posttreatment attacks needs further study.

Open-label, long-term tolerability of naratriptan for short-term prevention of menstrually related migraine

BACKGROUND

Although naratriptan is not approved for prophylactic use in migraine, naratriptan has been shown to be significantly more effective than placebo for short-term prevention of menstrually related migraine (MRM). The tolerability of naratriptan administered intermittently for prophylaxis for MRM over the long term has not been assessed.

OBJECTIVE

To assess the tolerability of naratriptan 1 mg given twice daily for 6 days per month, administered for up to 1 year for short-term prevention of MRM in an open-label study.

METHODS

Patients were eligible for the study if they were between 18 and 65 years of age and had at least a 1-year history of migraine, with or without aura, as defined by 1988 International Headache Society criteria; reported a history of MRM; and had at least 1 MRM attack during their last menstrual cycle. MRM was defined as any migraine beginning during the perimenstrual period (PMP). By definition, the PMP consisted of Days -2, -1, 1, 2, 3, and 4, with Day 1 being the first day of menstrual flow. During each menstrual cycle occurring over a 1-year period, patients began short-term treatment with naratriptan 1 mg twice daily (BID) 3 days before the expected onset of MRM and treated for a total of 6 days. Naratriptan 2.5 mg could be taken for breakthrough MRM attacks. Tolerability and safety measures included adverse events, standard clinical laboratory tests, electrocardiograms (ECGs), and vital signs. The secondary endpoints were the percentage of PMPs without MRM; headache disability as measured by the Headache Impact Test (HIT), and psychological health as measured by the Beck Depression Inventory version 2 (BDI-II).

RESULTS

The number of patients who took at least 1 dose of study medication (safety population) was 457, and the numbers of patients completing 6 months and 12 months of treatment were 318 and 131, respectively. Note that 171 (37%) patients were asked to leave the study once target enrollment numbers were met. The only adverse event occurring at an incidence of more than 2% during the 6-day treatment periods when naratriptan 1 mg BID was taken with or without an additional 2.5-mg dose for breakthrough attacks was ear, nose, throat infection (3%). No specific adverse event considered at least possibly to be related to study medication occurred in more than 2% of patients. No serious drug-related adverse events were reported. Furthermore, no patient experienced clinically relevant drug-related changes in 12-lead ECGs, vital signs, or clinical laboratory tests. Patients in both the 6- and 12-month populations did not experience an MRM in approximately 50% of treated PMPs. Health outcomes results suggested that naratriptan reduced headache impact when used for up to 12 months for the short-term prevention of MRM.

CONCLUSION

Naratriptan 1 mg BID, with the optional use of an additional 2.5-mg dose for breakthrough attacks, was well tolerated when used for 6 continuous days per month for up to 1 year for short-term prevention of MRM.

A model-based approach to treatment comparison in acute migraine

AIMS

Currently, direct comparisons between 5-HT(1B/d) receptor agonists are used to assess differences and similarities in antimigraine response. Such comparisons depend on the selected sampling time and do not allow evaluation of entire response profiles. A thorough evaluation of drug properties requires that the time course of the response be taken into account. In this investigation we show the advantages of a model-based approach to compare the efficacy of two triptans (sumatriptan vs. naratriptan).

METHODS

A Markov model was used to describe the course of a migraine attack over three clinically identified stages. Drug effects were modelled as concentration-dependent increases in transition rates and were parameterised as potency (EC(50)) and maximum effect (E(max)). Parameters were estimated using headache measurements from efficacy studies. Model estimates were then used to compare the pharmacodynamics of the two drugs in a time-independent manner.

RESULTS

Efficacy parameters could be derived, allowing for comparison between compounds. The potency ratio (EC50(suma)/EC50(nara)) for headache relief was 3.3 (0.9, 12). The ratio of maximum effects (Emax(suma)/Emax(nara)) for this endpoint was 0.74 (0.55, 0.97). To interpret these efficacy measures and explore their value for the development of antimigraine drugs, results were evaluated against the reported in vitro potency at 5-HT(1B) and 5-HT(1D) receptors.

CONCLUSIONS

Comparison of the effects of two or more drugs based on preset sampling times does not allow proper assessment of the antimigraine properties in vivo. Disease dynamics must be considered to evaluate treatment response adequately and optimise the dosing regimen in migraine.

Efficacy of oral naratriptan in the treatment of menstrually related migraine

The aim of this study was to investigate the efficacy of orally administered 2.5 mg naratriptan in the treatment of menstrually related migraine (MRM). A high percentage of women suffering from migraine report increased frequency of attacks in association with menstruation that may be more severe, of longer duration and more difficult to treat than at other times. This was a phase IIIb, randomized, double-blind, placebo-controlled clinical trial. Subjects were given either 2.5 mg naratriptan or placebo to treat a single MRM episode, defined as starting between days -2 and +4 relative to the start of menstruation. The primary efficacy measure was the percentage of subjects who were free of pain 4 h after treatment, the absence of pain at 30 min, 1 and 2 h being secondary efficacy measures. Other secondary measures were the absence of associated symptoms, sustained headache relief 24 h after a single dose of the study medication, recourse to a second dose of study medication or escape medication, pain intensity 4-24 h after first treatment, the ability to carry out work or daily activities, and patient satisfaction. Adverse events were also monitored. A total of 275 women were enrolled in the trial and 229 (115 naratriptan group, 114 placebo group) provided data on the effects of the study medication on MRM. A higher percentage of subjects in the naratriptan group (58%) reported complete pain relief 4 h after medication than in the placebo group (30%) (P<0.001). Significant differences between the naratriptan and placebo groups and in favor of naratriptan were also found for: total pain relief at 2 h (P=0.004), sustained pain-free response within 4-24 h (P<0.001), absence of all associated symptoms at 2 and 4 h (P=0.004), ability to work and carry out daily activities at 2 h (P=0.036), and patient overall satisfaction (P<0.001). Three adverse events were recorded that might potentially be attributable to naratriptan. Naratriptan given orally at a dose of 2.5 mg is effective in the acute treatment of MRM as early as 2 h after treatment.

Methodological issues in systematic reviews of headache trials: adapting historical diagnostic classifications and outcome measures to present-day standards

Recent efforts to make headache diagnostic classification and clinical trial methodology more consistent provide valuable advice to trialists generating new evidence on effectiveness of treatments for headache; however, interpreting older trials that do not conform to new standards remains problematic. Systematic reviewers seeking to utilize historical data can adapt currently recommended diagnostic classification and clinical trial methodological approaches to interpret all available data relative to current standards. In evaluating study populations, systematic reviewers can: (i) use available data to attempt to map study populations to diagnoses in the new International Classification of Headache Disorders; and (ii) stratify analyses based on the extent to which study populations are precisely specified. In evaluating outcome measures, systematic reviewers can: (i) summarize prevention studies using headache frequency, incorporating headache index in a stratified analysis if headache frequency is not available; (ii) summarize acute treatment studies using pain-free response as reported in directly measured headache improvement or headache severity outcomes; and (iii) avoid analysis of recurrence or relapse data not conforming to the sustained pain-free response definition.

Cardiovascular tolerability and safety of triptans: a review of clinical data

Triptans are not widely used in clinical practice despite their well-established efficacy, endorsement by the US Headache Consortium, and the demonstrable need to employ effective intervention to reduce migraine-associated disability. Although the relatively restricted use of triptans may be attributed to several factors, research suggests that prescribers' concerns about cardiovascular safety prominently figure in limiting their use. This article reviews clinical data--including results of clinical trials, postmarketing studies and surveillance, and pharmacodynamic studies--relevant to assessing the cardiovascular safety profile of the triptans. These data demonstrate that triptans are generally well tolerated. Chest symptoms occurring during use of triptans are usually nonserious and usually not attributed to ischemia. Incidence of triptan-associated serious cardiovascular adverse events in both clinical trials and clinical practice appears to be extremely low. When they do occur, serious cardiovascular events have most often been reported in patients at significant cardiovascular risk or in those with overt cardiovascular disease. Adverse cardiovascular events also have occurred, however, in patients without evidence of cardiovascular disease. Several lines of evidence suggest that nonischemic mechanisms are responsible for sumatriptan-associated chest symptoms, although the mechanism of chest symptoms has not been determined to date. Importantly, most of the clinical trials and clinical practice data on triptans are derived from patients without known cardiovascular disease. Therefore, the conclusions of this review cannot be extended to patients with cardiovascular disease. The cardiovascular safety profile of triptans favors their use in the absence of contraindications.

Consensus Statement: Cardiovascular Safety Profile of Triptans (5-HT1B/1D Agonists) in the Acute Treatment of Migraine

BACKGROUND

Health care providers frequently cite concerns about cardiovascular safety of the triptans as a barrier to their use. In 2002, the American Headache Society convened the Triptan Cardiovascular Safety Expert Panel to evaluate the evidence on triptan-associated cardiovascular risk and to formulate consensus recommendations for making informed decisions for their use in patients with migraine.

OBJECTIVE

To summarize the evidence reviewed by the Triptan Cardiovascular Safety Expert Panel and their recommendations for the use of triptans in clinical practice.

PARTICIPANTS

The Triptan Cardiovascular Safety Expert Panel was composed of a multidisciplinary group of experts in neurology, primary care, cardiology, pharmacology, women's health, and epidemiology.

EVIDENCE AND CONSENSUS PROCESS

An exhaustive search of the relevant published literature was reviewed by each panel member in preparation for an open roundtable meeting. Pertinent issues (eg, cardiovascular pharmacology of triptans, epidemiology of cardiovascular disease, cardiovascular risk assessment, migraine) were presented as a prelude to group discussion and formulation of consensus conclusions and recommendations. Follow-up meetings were held by telephone.

CONCLUSIONS

(1) Most of the data on triptans are derived from patients without known coronary artery disease. (2) Chest symptoms occurring during use of triptans are generally nonserious and are not explained by ischemia. (3) The incidence of serious cardiovascular events with triptans in both clinical trials and clinical practice appears to be extremely low. (4) The cardiovascular risk-benefit profile of triptans favors their use in the absence of contraindications.

Placebo adverse events in headache trials: headache as an adverse event of placebo

We analysed the adverse events of placebo in acute and preventive randomized, double-blind, placebo-controlled studies for migraine treatment. Fifty-seven trials (oral triptans, non-steroidal anti-inflammatory drugs, nasal ergot alkaloids and preventive agents) were included. From 10 to 30% of subjects reported adverse events after placebo. Most common were features associated with a migraine attack, such as nausea, phono- and photophobia. Other frequent complaints resembled those of the active drug (e.g. chest pressure in triptan trials). A third group of adverse events appeared to be coincidental (e.g. sleep disturbance). Adverse events following placebo are probably related to the drug under study and the symptomatology of migraine; some have no obvious explanation.

Effects of naratriptan versus naproxen on daily functioning in the acute treatment of migraine: a randomized, double-blind, double-dummy, crossover study

OBJECTIVE

To evaluate the effect of acute treatment on ictal behavioral functioning of patients with migraine via ambulatory accelerometry.

BACKGROUND

The inability to carry out daily activities often complicates migraine attacks. Research into the effects of pharmacological drugs on this outcome parameter in the acute treatment of migraine has been based on subjective reports only.

METHODS

In a double-blind, double-dummy, crossover study, 12 patients with migraine treated 2 migraine attacks with the nonspecific antimigraine drug, naproxen (500-mg capsule) or the more specific antimigraine drug, naratriptan (2.5-mg tablet). The clinical symptoms of headache, nausea, vomiting, photophobia, and phonophobia, and the subjective symptoms reflecting mood, sleepiness, and level of functioning were measured by use of a daily log.

RESULTS

During the first 6 hours after intake of the study medication, the objective behavioral parameters showed no significant effect of time and no significant differences between naproxen and naratriptan, but naratriptan was significantly more efficacious than naproxen in relieving headache, nausea, and vomiting; the interval between treatment and relief was significantly shorter after intake of naratriptan.

CONCLUSIONS

Consciously perceived clinical and subjective symptoms do not necessarily run in parallel with their behavioral equivalents. It, thus, may be important to assess the effects of treatment on behavioral functioning in the evaluation of the general efficacy of antimigraine drugs in the acute treatment of a migraine attack.

The triptan formulations : how to match patients and products

The 5-HT(1B/1D) receptor agonists (the 'triptans') are migraine-specific agents that have revolutionised the treatment of migraine. They are usually the drugs of choice to treat a migraine attack in progress. Different triptans are available in various strengths and formulations, including oral tablets, orally disintegrating tablets, nasal sprays and subcutaneous injections. In Europe, sumatriptan is also available as a suppository. Specific differences among the triptans exist, as evidenced by different pharmacological profiles including half-life, time to peak plasma concentrations, peak plasma concentrations, area under the concentration-time curve, metabolism and drug-drug interaction profiles. How or whether these differences translate to clinical efficacy and tolerability advantages for one agent over another is not well differentiated. However, delivery systems may play an important role in onset of action. Given that the clinical distinctions among these agents are subtle, identification of the most appropriate triptan for an individual patient requires consideration of the specific characteristics of the patient and knowledge of patient preference, an accurate history of the efficacy of previous acute-care medications and individual features of the drug being considered. The selection of an acute antimigraine drug also depends upon the stratification of the patient's migraine attack by peak intensity, time to peak intensity, level of associated symptoms such as nausea and vomiting, time to associated symptoms, comorbid diseases and concomitant treatments that might cause drug-drug interactions. Individual patient response to the triptans seems to be idiosyncratic and possibly genetically determined. Therefore, a set of specific questions can be used to determine whether a currently used triptan is optimally effective, whether the dose needs to be increased or whether another triptan should be tried. The clinician has in his/her armamentarium an ever-expanding variety of triptans, available in multiple formulations and dosages, which have good safety and tolerability profiles. Continued clinical use will yield familiarity with the various triptans, and it should become possible for the interested physician to match individual patient needs with the specific characteristics of a triptan to optimise therapeutic benefit. Use of the methods outlined in this review in choosing a triptan for an individual patient is probably more likely to lead to migraine relief than making an educated guess as to which triptan is most appropriate.

Naratriptan in the preventive treatment of refractory chronic migraine: a review of 27 cases

OBJECTIVE

To review the efficacy of naratriptan as preventive treatment in 27 patients with chronic migraine refractory to other commonly used preventive therapies.

BACKGROUND

The treatment of chronic migraine often poses a major challenge to the clinician. Even when given expert care, patients with chronic migraine may continue to have daily or near-daily headaches.

METHODS

Clinical records and headache calendars were reviewed of 27 patients fulfilling the following inclusion criteria: (1) aged 18 to 65 years; (2) diagnosis of chronic migraine (formerly transformed migraine), according to the criteria proposed by Silberstein et al; (3) previous failure of at least 4 preventive medications prescribed as part of a management program that included nonpharmacological measures, preventive medication, acute care medication, and detoxification from overused medication; and (4) have used daily naratriptan for no less than 2 consecutive months. The dose of naratriptan prescribed was 2.5 mg twice daily. We considered the following outcomes: (1) frequency of headache, (2) intensity of pain, (3) number of days per month with severe headache, (4) headache index (frequency times intensity), and (5) proportion of patients who reverted to an episodic pattern of pain after 6 months of treatment.

RESULTS

There was a statistically significant reduction in the frequency of headache days 2 months (15.3 days versus 24.1 days at baseline, P<.001), 6 months (9.1 days, P<.001), and 1 year (7.3 days, P<.001) after daily treatment with naratriptan was initiated. There was also a statistically significant reduction in the number of days per month of severe pain at 1 month (5.6 days versus 12.5 days at baseline, P<.01), 2 months (5.7 days, P<.01), 6 months (2.8 days, P<.01), and 1 year (2.6 days, P<.01). Similarly, there was a statistically significant reduction in the headache index at 2 months (33 versus 56.4 at baseline, P<.001), 6 months (19.5, P<.001), and 1 year (17.2, P<.001). Of the 20 patients who continued to use naratriptan daily for at least 6 months, 13 (65%) reverted to an episodic pattern of pain (migraine). At 1 year, 11 (55%) still continued to experience episodic headache, 1 (5%) relapsed to chronic migraine, and 2 (10%) were lost to follow-up. No patients had intolerability to naratriptan during the treatment period, and no one stopped treatment due to adverse events.

CONCLUSIONS

Naratriptan may have a role in the preventive treatment of intractable chronic migraine. Prospective, controlled studies should be considered.

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.

Triptans (serotonin, 5-HT1B/1D agonists) in migraine: detailed results and methods of a meta-analysis of 53 trials

The triptans, selective serotonin 5-HT1B/1D agonists, are very effective acute migraine drugs. Soon, seven different triptans will be clinically available at 13 different oral doses, making evidence-based selection guidelines necessary. Triptan trials have similar designs, facilitating meta-analysis. We wished to provide an evidence-based foundation for using triptans in clinical practice, and to review the methodological issues surrounding triptan trials. We asked pharmaceutical companies and the principal investigators of company-independent trials for the 'raw patient data' of all double-blind, randomized, controlled, clinical trials with oral triptans in migraine. All data were cross-checked with published or presented data. We calculated summary estimates across studies for important efficacy and tolerability parameters, and compared these with those from direct, head-to-head, comparator trials. Out of 76 eligible clinical trials, 53 (12 not yet published) involving 24089 patients met the criteria for inclusion. Mean results (and 95% confidence intervals) for sumatriptan 100 mg, the first available and most widely prescribed oral triptan, are 59% (57-60) for 2 h headache response (improvement from moderate or severe to mild or no pain); 29% (27-30) for 2 h pain free (improvement to no pain); 20% (18-21) for sustained pain free (pain free by 2 h and no headache recurrence or use of rescue medication 2-24 h post-dose), and 67% (63-70) for consistency (response in at least two out of three treated attacks); placebo-subtracted proportions for patients with at least one adverse event (AE) are 13% (8-18), for at least one central nervous system AE 6% (3-9), and for at least one chest AE 1.9% (1.0-2.7). Compared with these data: rizatriptan 10 mg shows better efficacy and consistency, and similar tolerability; eletriptan 80 mg shows better efficacy, similar consistency, but lower tolerability; almotriptan 12.5 mg shows similar efficacy at 2 h but better sustained pain-free response, consistency, and tolerability; sumatriptan 25 mg, naratriptan 2.5 mg and eletriptan 20 mg show lower efficacy and better tolerability; zolmitriptan 2.5 mg and 5 mg, eletriptan 40 mg, and rizatriptan 5 mg show very similar results. The results of the 22 trials that directly compared triptans show the same overall pattern. We received no data on frovatriptan, but publicly available data suggest substantially lower efficacy. The major methodological issues involve the choice of the primary endpoint, consistency over multiple attacks, how to evaluate headache recurrence, use of placebo-subtracted proportions to control for across-study differences, and the difference between tolerability and safety. In addition, there are a number of methodological issues specific for direct comparator trials, including encapsulation and patient selection. At marketed doses, all oral triptans are effective and well tolerated. Differences among them are in general relatively small, but clinically relevant for individual patients. Rizatriptan 10 mg, eletriptan 80 mg and almotriptan 12.5 mg provide the highest likelihood of consistent success. Sumatriptan features the longest clinical experience and the widest range of formulations. All triptans are contra-indicated in the presence of cardiovascular disease.

Headache Recurrence and Treatment

The definition of recurrence includes the following: any headache occurring after a headache-free state at 2 hours and within 24 hours after intake of drug; a headache that has never been studied systematically; a headache that may not be an outcome of drug treatment; a headache that may be due to the inherent nature of migraine and individual patient characteristics such as duration of attack; and headache for which effective treatment may be a re-dose of the initial medication or addition of steroidal or nonsteroidal anti-inflammatory medications.

Practical approaches to migraine management

Migraine is a recurrent clinical syndrome characterised by combinations of neurological, gastrointestinal and autonomic manifestations. The exact pathophysiological disturbances that occur with migraine have yet to be elucidated; however, cervico-trigemino-vascular dysfunctions appear to be the primary cause. Despite advances in the understanding of the pathophysiology of migraine and new effective treatment options, migraine remains an under-diagnosed, under-treated and poorly treated health condition. Most patients will unsuccessfully attempt to treat their headaches with over-the-counter medications. Few well designed, placebo-controlled studies are available to guide physicians in medication selection. Recently published evidence-based guidelines advocate migraine-specific drugs, such as serotonin 5-HT(1B/1D) agonists (the 'triptans') and dihydroergotamine mesylate, for patients experiencing moderate to severe migraine attacks. Additional headache attack therapy options include other ergotamine derivatives, phenothiazines, nonsteroidal anti-inflammatory agents and opioids. Preventative medication therapy is indicated for patients experiencing frequent and/or refractory attacks.

Almotriptan is an effective and well-tolerated treatment for migraine pain: results of a randomized, double-blind, placebo-controlled clinical trial

Almotriptan is a novel and specific serotonin 5-HT1B/1D agonist for the acute treatment of migraine. This randomized, single-dose, double-blind, multicentre, study assessed the efficacy and safety of oral almotriptan (12.5 mg and 25 mg) in patients with migraine, and compared it with the standard treatment (sumatriptan 100 mg) and placebo. A total of 668 patients treated one migraine attack of moderate or severe intensity with study medication. The primary efficacy assessment was migraine pain relief, improvement from severe or moderate pain to mild or no pain, at 2 h after treatment. Response rates, stratified for variation in baseline pain levels, for both almotriptan doses were equivalent to sumatriptan and significantly better than placebo. Other efficacy assessments confirmed the equivalence of the almotriptan groups with the sumatriptan group. Almotriptan 12.5 mg was as well tolerated as placebo (P=0.493) and significantly better tolerated than sumatriptan (P<0.001), in terms of the overall incidence of adverse events. There was no statistically significant difference in the incidence of adverse events between almotriptan 25 mg and sumatriptan 100 mg (P=0.376). The results from this large clinical study indicate that the new, specific 5-HT1B/1D agonist, almotriptan, is an effective and well-tolerated treatment for migraine pain.

Assessing the efficacy of drugs for the acute treatment of migraine: issues in clinical trial design

Clinical trials of therapies for acute migraine attacks have evolved over the years from open-label, small observational studies to highly structured randomised, controlled trials. The International Headache Society Committee on Clinical Trials in Migraine developed a tool to guide in designing scientifically sound trials. The proof of effect is best achieved in a clinical trial with: clearly defined objectives;a well-characterised study population, identified using well-validated diagnostic tools;proper randomisation and blinding;inclusion of a placebo arm, with proper balancing of patients receiving placebo and those receiving active drug;adequate study power; and appropriate statistical methods. Both parallel and crossover studies may be suitable in clinical trials of antimigraine agents, although the latter are a better choice in patient preference and bioequivalence studies. Although various efficacy measures are used to assess treatment effect, the 2-hour pain free rate (total resolution of pain within 2 hours after an initial moderate to severe headache) is preferred because it is clinically relevant and is relatively 'placebo-insensitive'. Various migraine surveys have indicated that a rapid onset of therapeutic effect is a highly desirable attribute of an antimigraine drug. Therefore, accurate measurements of treatment effect before 2 hours are becoming increasingly emphasised. Consistency of effect across multiple attacks adds to the understanding of the therapeutic efficacy of a test drug. Finally, preference and satisfaction studies allow us to assess patients' global impression of a particular treatment, weighing the positive effects on pain and associated symptoms of migraine against potential adverse effects.

Clinical efficacy of frovatriptan: placebo-controlled studies

OBJECTIVE

To confirm the clinical efficacy of frovatriptan 2.5 mg.

BACKGROUND

Frovatriptan is a new 5-hydroxytryptamine (5-HT)(1B/1D) receptor agonist being developed for the acute treatment of migraine with or without aura. Results from preclinical and clinical pharmacology studies showed frovatriptan to be a potent 5-HT(1B) receptor agonist with a long terminal elimination half-life (26 hours) and a broad therapeutic index.

DESIGN

Three randomized, placebo-controlled, double-blind, parallel-group trials, in a total of 2676 patients, were performed to confirm the clinical efficacy of frovatriptan 2.5 mg for the acute treatment of migraine.

RESULTS

In all three studies, headache response 2 hours after frovatriptan dosing was significantly greater than that seen with placebo (P < or = .001) with approximately a two-fold measure of effect over placebo for headache response at 2 and 4 hours postdosing. Time to headache response occurred within 1.5 hours in a substantial proportion of patients. The incidence of 24-hour headache recurrence with frovatriptan was low (10% to 25%). Frovatriptan therapy also was associated with a high degree of patient satisfaction.

CONCLUSIONS

Frovatriptan represents a consistently effective acute treatment for migraine and accompanying symptoms.

Triptans: are they all the same?

The triptans have provided a major advance in the treatment of the pain and disability associated with migraine headache. With seven triptans in use or in clinical development, the clinician is faced with the decision of which triptan to prescribe to the patient with migraine. Although the triptans are pharmacologically similar, they each have unique attributes. This article focuses on the pharmacologic differences between triptans with regard to their pharmacokinetics and drug interactions, and provides some helpful tips on how to optimize migraine treatment with the triptans.

Dose range-finding studies with frovatriptan in the acute treatment of migraine

OBJECTIVE

To determine the optimum dose of frovatriptan for the acute treatment of migraine.

BACKGROUND

Frovatriptan is a new triptan developed for the acute treatment of migraine. The dose-response characteristics and safety of frovatriptan have been investigated across a broad range of doses from 0.5 to 40 mg.

DESIGN

Two randomized, placebo-controlled, double-blind, parallel-group trials, with a total of 1453 patients, were performed to determine the optimal dose of the 5-HT(B/1D)agonist, frovatriptan, for the acute treatment of migraine. The dose ranges studied were 2.5 to 40 mg in the high-dose study and 0.5 to 5 mg in the low-dose study.

RESULTS

At 2 hours postdosing for initial moderate or severe headache (International Headache Society grades 2 or 3), there was an approximate two-fold difference in the proportion of patients taking frovatriptan doses of 2.5 to 40 mg with mild or no headache compared to placebo. Frovatriptan doses of 0.5 mg and 1 mg were not more effective than placebo at 2 hours postdose, and 2.5 mg was identified as the lowest effective dose for the relief of migraine and accompanying symptoms. Above 2.5 mg, no dose-response relationship was observed for any efficacy parameters. There was an increase in the incidence of adverse events from 10 mg and above, but the vast majority were rated as mild in severity and did not impact upon tolerability in a significant manner.

CONCLUSIONS

Frovatriptan was well tolerated throughout the dose range of 0.5 to 40 mg. The 2.5-mg dose confers the optimal balance of efficacy and tolerability for the acute treatment of migraine.

How does almotriptan compare with other triptans? A review of data from placebo-controlled clinical trials

Almotriptan, the new selective 5-HT1B/1D agonist, has a higher oral bioavailability than any other triptan, with more than two thirds of the administered dose absorbed within the first hour both inside and outside of a migraine attack. Gender or the presence of food in the stomach does not affect its pharmacokinetic profile, and the compound has no clinically relevant interactions with other drugs. Among the available triptans, response rates at 2 hours range from 50% to 80%, with 20% to 50% of patients pain-free. Almotriptan 12.5 mg provides similar efficacy, with significant advantage over placebo at 30 minutes and a reliable consistency (75% in two of three attacks). Headache typically recurs in 25% to 45% of patients with most triptans. The recurrence rate with almotriptan 12.5 mg, 18% to 27%, is among the lowest reported. The tolerability of almotriptan 12.5 mg is close to that of placebo with a low incidence of central nervous system side effects and chest symptoms. In conclusion, almotriptan's consistent pharmacokinetics and good efficacy, in combination with excellent tolerability, make it an attractive choice in the acute treatment of migraine attacks.

The safety of triptans in the treatment of patients with migraine

The introduction of the triptans (5-hydroxytryptophan [5-HT] (1B/1D) agonists) in the past decade has brought migraine-specific pain relief to those suffering from migraine. These drugs activate the serotonin receptors 5-HT(1B) and 5-HT(1D) on cerebral vessels. Concerns about their safety, particularly in patients with vascular risk factors, have been raised because triptans also activate the 5-HT(1B) receptors on coronary arteries. Although triptans are contraindicated in patients with cardiac or cerebrovascular disease, they are safer than many other medications used to treat patients with migraine, including the nonspecific serotonin-agonist ergot preparations.

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

OBJECTIVE

To determine the optimal dose and tolerability of frovatriptan in the acute treatment of migraine.

BACKGROUND

Frovatriptan has a distinctive pharmacological and pharmacokinetic profile compared with sumatriptan. A previous study has shown that frovatriptan doses of 2.5, 5, 10, 20, and 40 mg are equally effective in relieving headache with no evidence of a dose-response relationship. The incidence of adverse events tended to increase with doses of 10 mg and above.

METHODS

This study was a randomized, double-blind, placebo-controlled, parallel-group multicenter trial. Patients (n=635) took a single oral dose of placebo or frovatriptan, 0.5, 1, 2.5, or 5 mg, at the onset of a moderate or severe migraine headache and recorded headache intensity, functional impairment, and migraine-associated symptoms over 24 hours.

RESULTS

Frovatriptan 2.5 mg produced clinically and statistically significant headache relief 2 hours post-dose, whereas the effect of lower doses was not significantly different from that of placebo at that time point. The 2.5-mg dose also produced significant symptom relief and improvement in functional impairment. All doses of frovatriptan were well tolerated, and the majority of adverse events were of mild or moderate severity.

CONCLUSION

It is concluded that the 2.5-mg dose of frovatriptan offers optimal efficacy and tolerability in the treatment of acute migraine. Higher doses do not appear to confer greater efficacy and are associated with an increased incidence of adverse effects.

New paradigms in the recognition and acute treatment of migraine

It would be ideal if clinical decisions regarding acute migraine treatment could be made on the basis of three parameters: a critical appraisal of available scientific evidence, clinical experience (including knowledge of the individual patient and his/her attack characteristics), and, of course, patient preferences. Patients are likely to prefer agents that offer rapid relief, pain-free status within 2 hours, no recurrence or need for rescue medication, extended time to recurrence (if present), consistency of therapeutic effect over multiple attacks, oral administration. good tolerability, safety, and minimal drug interactions. Fortunately, a number of specific therapies now are available which place these objectives within the patient's reach. Ongoing barriers to optimal migraine care include underrecognition, underconsultation, undertreatment, restrictions imposed by insurance companies, and exaggerated concerns regarding the safety of the triptans. Overcoming these barriers is likely to prove a more important contribution to patient care than endeavoring to establish the relative merits of one triptan over another. We have described in detail a number of strategies for improving recognition and treatment of migraine. Many headache specialists now believe that recurrent episodes of disabling headache, with a stable pattern over years, should be viewed as migraine until proven otherwise. In the end, this may represent the most useful paradigm in the primary care setting, where time is of the essence. Studies to validate this approach are needed. Acute treatment intervention that is based on scientific evidence, clinical experience, and patients' needs and desires will provide better outcomes than those presently obtained. Preliminary evidence favors early intervention with oral triptans, and randomized, prospective, double-blind, placebo-controlled studies, ideally employing a crossover design, are required to confirm this. The US Consortium's evidence-based guidelines, the National Headache Foundation's standards of care, and the Canadian guidelines have applied the standards of scientific inquiry to the field of headache management and "translation" of these guidelines into practical instruments for clinicians through vehicles such as the Primary Care Network's Patient-Centered Strategies for Effective Management of Migraine should raise the general standard of care for patients with migraine. Last, but far from least, initiatives undertaken by the World Health Organization (WHO) will add credibility to the many layfolk and professionals who have struggled to present headache as a disabling disorder worthy of scientific investigation and aggressive medical management. The WHO states: "These common complaints impose a significant health burden ... Despite this, both the public and the majority of healthcare professionals tend to perceive headache as a minor or trivial complaint. As a result, the physical, emotional, social and economic burdens of headache are poorly acknowledged in comparison with those of other, less prevalent, neurologic disorders." Migraine is finally out of the closet.

Pharmacokinetics and pharmacodynamics of the triptan antimigraine agents: a comparative review

The current approach to antimigraine therapy comprises potent serotonin 5-HT1B/1D receptor agonists collectively termed triptans. Sumatriptan was the first of these compounds to be developed, and offered improved efficacy and tolerability over ergot-derived compounds. The development of sumatriptan was quickly followed by a number of 'second generation' triptan compounds, characterised by improved pharmacokinetic properties and/or tolerability profiles. Triptans are believed to effect migraine relief by binding to serotonin (5-hydroxy-tryptamine) receptors in the brain, where they act to induce vasoconstriction of extracerebral blood vessels and also reduce neurogenic inflammation. Although the pharmacological mechanism of the triptans is similar, their pharmacokinetic properties are distinct. For example, bioavailability of oral formulations ranges between 14% (sumatriptan) and 74% (naratriptan), and their elimination half-life ranges from 2 hours (sumatriptan and rizatriptan) to 25 hours (frovatriptan). Clearly, such diverse pharmacokinetic properties will influence the effectiveness of the compounds and favour the prescription of one over another in different patient populations. This article reviews the pharmacological properties of the triptans (time to peak plasma concentration, half-life, bioavailability and receptor binding) and relates these properties to efficacy and time of onset. It also considers the effects of concomitant medication, food, age and disease on the pharmacokinetics of the compounds. In addition, the relative merits, such as headache recurrence, tolerability and route of administration, are discussed. Finally, the performance of the triptans is considered in the context of direct head-to-head comparative trials that have assessed the efficacy profile of the compounds.

Tolerability and efficacy of almotriptan in the long-term treatment of migraine

BACKGROUND

Almotriptan is a highly specific 5-HT(1B/1D) receptor agonist, which acts selectively on blood vessels of the brain. Short-term studies have demonstrated that almotriptan provides rapid, effective and reliable relief of migraine attacks, while offering excellent tolerability.

PURPOSE

To assess the long-term tolerability and efficacy of oral almotriptan 12.5 mg administered for every migraine attack over a 1-year period.

METHODS

A total of 762 patients treated 13,751 attacks (1-97 per patient); 61.5% of attacks were treated with one 12.5-mg dose, while for 38.5% of attacks, patients took a second dose within 24 h.

RESULTS

Three hundred and ninety-one patients (51.3%) experienced a total of 1,617 adverse events (AEs). The majority (88.6%) of AEs were of mild-to-moderate intensity, and only 28.8% of AEs were considered to be related to the study drug. Only 2 patients experienced serious AEs possibly related to almotriptan, syncope and chest pain; both recovered without any sequelae. Patients reported at least 1 AE in 11% of attacks treated. The incidence of AEs decreased during the study. Only 6 (0.8%) study withdrawals were due to AEs considered to be related to almotriptan. Tolerability was not compromised in patients taking 2 doses of almotriptan or in those using migraine prophylactics. Patient age or sex did not influence the incidence of AEs. There was no evidence of tachyphylaxis in those patients completing the study. Pain relief at 2 h after the initial dose was achieved in 84.2% of moderate/severe attacks. Patients were pain free at 2 h after dose in 58.2% of all attacks. Older patients (> 40 years) tended to respond better than younger ones (< 40 years). Efficacy was not modified by use of migraine prophylactics or hormonal contraceptives. Efficacy measurements were consistent on treating repeated moderate/severe migraine attacks.

CONCLUSION

This large, open study indicates that the new, specific 5-HT(1B/1D) agonist almotriptan, at a dose of 12.5 mg, is a well tolerated and effective treatment for migraine pain when used over a period of up to 1 year.

Safety and rational use of the triptans

The safety of the triptans has been established, with more than 8 million patients treating greater than 340 million attacks with sumatriptan alone. All triptans narrow coronary arteries by 10% to 20% at clinical doses and should not be administered to patients with coronary or cerebrovascular disease. Some triptans have the potential for significant drug-drug interactions (sumatriptan, rizatriptan, and zomitriptan and monoamine oxidase inhibitors; rizatriptan and propanolol; zolmitriptan and cimetidine; and eletriptan and CYP3A4 metabolized medications and p-glycoprotein pump inhibitors). Rational use of triptans should be governed by the use of these medications for patients with disability associated with migraine. Patients with greater than 10 days of at least 50% disability during 3 months have benefited from treating with triptans as their first-line treatment for acute attacks. When the decision has been made to treat with a triptan, the patient should be instructed to treat early in the attack, when the pain is at a mild phase. This approach increases the likelihood of achieving a pain-free response, with fewer adverse events and lower likelihood of the headache recurring.

Treatment of migraine in Canada with naratriptan: a cost-effectiveness analysis

OBJECTIVE

To evaluate the cost-effectiveness of naratriptan for the treatment of migraine in Canada.

BACKGROUND

The substantial disability brought on by migraine, coupled with the high prevalence of this disorder, leads to substantial costs. Naratriptan is a newly developed triptan shown to be effective in the treatment of migraine.

METHODS

Monte Carlo modeling techniques were used to simulate the experience of Canadian migraineurs over the course of 1 year. Data from a multinational study comparing oral naratriptan 2.5 mg to customary therapies were used in the cost-effectiveness analysis.

RESULTS

Naratriptan leads to an annual reduction in symptom duration of 225 hours compared to customary therapy not including other triptans. Reductions in lost productivity yield savings of Can $390 (1998 Canadian dollars) relative to customary therapy, which exceed the increase in drug costs resulting in overall savings of Can $109 per year.

CONCLUSIONS

The use of naratriptan in the treatment of migraine is an economically attractive option, leading to savings in overall costs. Increases in drug costs seem acceptable in light of reductions in symptom duration.

Naratriptan as short-term prophylaxis of menstrually associated migraine: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To determine the efficacy of naratriptan 1-mg and 2.5-mg tablets twice daily compared with placebo as short-term prophylaxis of menstrually associated migraine.

BACKGROUND

Approximately 60% of women with migraine report headaches associated with their menstrual cycles. Results from an open-label study suggest that short-term administration of sumatriptan is useful in the prophylaxis of menstrually associated migraine.

METHODS

A randomized, double-blind, three-arm, parallel-group, placebo-controlled study was conducted in women aged 18 years or older with a history of migraine with or without aura, as defined by the International Headache Society, of at least 6 months. Two dose strengths of naratriptan (1 mg, 2.5 mg) or identical-appearing placebo tablets (1:1:1) were administered twice daily for 5 days starting 2 days prior to the expected onset of menses across four perimenstrual periods. End points included the number of menstrually associated migraines, total migraine days, peak headache severity, lost work/activity time, migraine-related quality of life, and incidence of adverse events.

RESULTS

Overall, the intent-to-treat population comprised 206 women (naratriptan 1 mg, n = 70; naratriptan 2.5 mg, n = 70, and placebo, n = 66); 171 women treated four perimenstrual periods. Significantly more perimenstrual periods per subject treated with naratriptan, 1 mg, were headache-free compared with placebo (50% versus 25%, P =.003). Naratriptan, 1 mg, significantly reduced the number of menstrually associated migraines (2.0 versus 4.0, P <.05) and menstrually associated migraine days (4.2 versus 7.0, P <.01) compared with placebo. More patients treated with naratriptan, 1 mg, were headache-free across all treated perimenstrual periods compared with placebo (23% versus 8%). No difference in headache severity was observed in breakthrough headaches. The incidence and severity of adverse events was similar across treatment groups. Naratriptan, 2.5 mg, was not statistically superior to placebo for any measure.

CONCLUSIONS

Naratriptan, 1 mg, with tolerability similar to placebo, is an effective, short-term, prophylactic treatment for menstrually associated migraine.

Differentiating the efficacy of 5-HT(1B/1D) agonists

OBJECTIVE

To examine, for a set of published clinical trials of serotonin (5-HT(1B/1D)) agonists as acute treatments for migraine, whether transformation of efficacy data into therapeutic gain (TG) or number needed to treat (NNT) is useful.

BACKGROUND

Pivotal clinical trials of 5-HT(1B/1D) agonists in migraine use a primary end point of change in pain score from 3 or 2 to 1 or 0. Placebo response rates among such studies are variable. Meta-analytic comparisons of 5-HT(1B/1D) agonists often employ TG and NNT as efficacy measures.

METHODS

Data from US product labeling or published sources were converted into TG (TG = active response rate [%] - placebo response rate [%]) and NNT (NNT = 1/TG). Pivotal clinical trial data were compared before and after transformation.

RESULTS

Therapeutic gain ranged from 17.5% to 51%. The transformation of TG into NNT yielded no clinically significant difference in efficacy estimate for the range of 17.5% to 47% (N = 29 clinical trials). However, NNT and TG had a nonlinear relationship for some secondary end points. When the relationship between the standard primary and secondary end points was compared, the correlation of TG with clinical disability (Pearson coefficient R = 0.93) was stronger than for NNT. Placebo response rates correlated more strongly with NNT (R = 0.66) than active response rates (R = 0.42; N = 29 clinical trials), although both TG and NNT were sensitive to placebo response rate.

CONCLUSIONS

Transforming efficacy rates into TG or NNT adds no new information to placebo-controlled trials. The variables, TG and NNT, should not be used to compare members of this class of drugs. Migraine therapies can only be compared using well-designed head-to-head studies and not by meta-analysis. Broader measures of efficacy should be used to describe and compare 5-HT(1B/1D) efficacy.

Gastric motor effects of triptans: open questions and future perspectives

Sumatriptan is a 5-HT1B/D receptor agonist of documented efficacy in relieving migraine and associated symptoms such as nausea and vomiting. In the past decade, several studies reported an important delay of gastric emptying induced by sumatriptan in healthy humans. The impact of this gastric motor effect of sumatriptan in migraineurs is difficult to predict: a further delay in gastric emptying could be detrimental (i.e. increased nausea and epigastric symptoms) in patients already having delayed gastric emptying. However, in patients with functional dyspepsia, sumatriptan is also reported to improve gastric accommodation to a meal and reduce perception of gastric distention, hence relieving epigastric symptoms. Thus, reduced visceral perception could be a mechanism involved in reducing nausea during a migraine attack. Paradoxically, sumatriptan is reported both to relieve the nausea of a migraine attack and to have nausea as a side effect. Although careful analysis of the time of onset of nausea may offer a clue as to the origin of this symptom, available data do not support definite conclusions, all the more so because the gastric motor effect of second-generation triptans are still unexplored. Taken together, the available evidence warrants further studies to clarify the following issues: first, the mechanism responsible for the gastric motor effect of sumatriptan [receptor subtype(s) involved; central vs peripheral mechanism]; secondly, the effects on gastric motility/visceral sensitivity of second-generation triptans (which are 5-HT1B/D receptor agonists) and more recent selective 5-HT1D receptor agonists (proposed as investigational antimigraine agents with less potential to induce coronary vasoconstriction through 5-HT1B receptors); finally, the possible use of drugs improving gastric accommodation to a meal in the management of those dyspeptic patients with impaired fundic relaxation/altered visceral sensitivity.