Subcutaneous Sumatriptan International Study Group. Treatment of migraine attacks with sumatriptan

Clinical pharmacokinetics of intranasal sumatriptan

A substantial proportion of migraine patients have gastric stasis and suffer severe nausea and/or vomiting during their migraine attack. This may lead to erratic absorption from the gastrointestinal tract and make oral treatment unsatisfactory. For such patients, an intranasal formulation may be advantageous. Sumatriptan is a potent serotonin 5HT(1B/1D) agonist widely used in the treatment of migraine; the effectiveness of the intranasal formulation (20mg) has been well established in several clinical studies. This article reviews the pharmacokinetics of intranasal sumatriptan and includes comparisons with oral and subcutaneous administration. After intranasal administration, sumatriptan is directly and rapidly absorbed, with 60% of the maximum plasma concentration (C(max)) occurring at 30 minutes after administration of a single 20mg dose. Following intranasal administration, approximately 10% more sumatriptan is absorbed probably via the nasal mucosa when compared with oral administration. Mean C(max) after a 20mg intranasal dose is approximately 13.1 to 14.4 ng/mL, with median time to C(max) approximately 1 to 1.75 hours. When given as a single dose, intranasal sumatriptan displays dose proportionality in its extent of absorption and C(max) over the dose range 5 to 10mg, but not between 5 and 20mg for C(max). The elimination phase half-life is approximately 2 hours, consistent with administration by other routes. Sumatriptan is metabolised by monoamine oxidase (MAO; predominantly the A isozyme, MAO-A) to an inactive metabolite. Coadministration with a MAO-A inhibitor, moclobemide, leads to a significant increase in sumatriptan plasma concentrations and is contraindicated. Single-dose pharmacokinetics in paediatric and adolescent patients following intranasal sumatriptan were studied to determine the effect of changes in nasal morphology during growth, and of body size, on pharmacokinetic parameters. The pharmacokinetic profile observed in adults was maintained in the adolescent population; generally, factors such as age, bodyweight or height did not significantly affect the pharmacokinetics. In children below 12 years, C(max) is comparable to that seen in adolescents and adults, but total exposure (area under the concentration-time curve from zero to infinity) was lower in children compared with older patients, especially in younger children treated with 5mg. Clinical experience suggests that intranasal sumatriptan has some advantages over the tablet (more rapid onset of effect and use in patients with gastrointestinal complaints) or subcutaneous (noninvasive and fewer adverse events) formulations.

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.

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.

Effects of sumatriptan on cerebral blood flow under normo- and hypercapnia in rats

To investigate further the pharmacological mechanism of an anti-migraine drug, sumatriptan, a 5-HT1B/1D receptor agonist, we studied its effect on the cerebral circulation in seven anaesthetized rats, particularly during hypercapnia. After injection of 0.6 or 6.0 microg/kg sumatriptan succinate, no significant change in cerebral blood flow (CBF) was observed either in the striatum or in the parietal cortex. The increase in CBF both in the parietal cortex and the striatum during 5% CO2 inhalation was significantly less when sumatriptan succinate 6.0 microg/kg was injected. Sumatriptan appeared to have a vasoconstrictor effect on the relaxed vessels by CO2 inhalation. This mechanism might be attributable to vasoconstriction through activation of 5-HT1B receptors located in the vascular smooth muscle rather than 5-HT1B receptors in the vascular adventitia.

Pharmacokinetics, pharmacodynamics, and safety of the 5-HT(1B/1D) agonist eletriptan following intravenous and oral administration

Four separate studies were conducted to examine the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of eletriptan, a 5-HT(1B/1D) receptor agonist being developed for the treatment of migraines, after oral and intravenous administration. Fifty-five males received oral (1.5-30 mg or 30-120 mg) or intravenous (1.67-50 microg/kg or 50-102 microg/kg) eletriptan in four double- and single-blind, placebo-controlled, ascending-dose crossover studies. The maximum plasma concentration (Cmax) and area under the concentration curve (AUC) appeared linear over all dose ranges, with an apparent terminal half-life of 4 to 5 hours. Clearance and volume of distribution remained constant with dose. The time to first occurrence of Cmax (tmax) for oral eletriptan was approximately 1 hour and was unaffected by dose. Comparison of AUC values suggested an absolute bioavailability of approximately 50%. A linear PK/PD model, fitted to the data, predicted small, transient elevations in diastolic blood pressure following eletriptan doses > or = 60 mg. These effects were considered unlikely to be clinically significant. Eletriptan was well tolerated, and treatment-related adverse events were mild to moderate and transient. These PK properties should result in eletriptan having a rapid onset and sustained duration of action in terms of migraine efficacy.

Migraine without aura and migraine with aura are distinct disorders. A population-based twin survey

OBJECTIVE

To investigate the co-occurrence of migraine without aura (MWOA) and migraine with aura (MWA) in a population-based twin survey.

BACKGROUND

Migraine without aura and MWA are multifactorial disorders. If MWOA and MWA share common genes, co-occurrence should be observed more frequently than expected, ie, the product of the prevalence in the general population.

MATERIAL AND METHODS

The study population included all living Danish monozygotic (MZ) and same-gender dizygotic (DZ) twin pairs born between 1953 and 1960: 5360 twins (2026 MZ, 3334 DZ). The sample included 2840 men and 2520 women. All received a posted questionnaire, and those with possible migraine were interviewed via telephone by trained physicians (V.U. or M.G.). Twins who did not respond to the questionnaire and who had a co-twin with possible migraine were contacted by telephone. The questionnaire response rate was 87% (4660 of 5360), and the telephone interview was participated in by 90% (2035 of 2272). The physician interviewers were unaware of questionnaire answers, zygosity, and the clinical diagnosis of the co-twin. The criteria of the International Headache Society were used to establish a diagnosis of migraine.

RESULTS

Lifetime prevalence in the twin sample: 7% of men and 19% of women had MWOA, while 7% of men and 8% of women had MWA. Lifetime prevalence of MWA in twin pairs with MWOA: MZ men, 2% (1 of 47); MZ women, 6% (5 of 90); DZ men, 9% (7 of 75); and DZ women, 10% (19 of 182). Lifetime prevalence of MWOA in twin pairs with MWA: MZ men, 3% (1 of 33); MZ women, 5% (3 of 58); DZ men, 9% (4 of 44); and DZ women, 13% (10 of 76). The observed and the expected numbers of twins with co-occurrence of MWOA and MWA based on the prevalence in the general population were not significantly different in either men or women (men, P=.1 and women, P=.5).

CONCLUSION

The results strongly suggest that MWOA and MWA are distinct disorders, and identification of common genes for MWOA and MWA, thus, should not be expected to result from future genetic research.

Triptans: do they differ?

Headache care specialists agree that the introduction of sumatriptan constitutes a major advance in headache therapy, but they differ about whether other triptans offer clinically significant advantages over sumatriptan. This article examines this issue by considering the similarities and differences among triptans.

New insights into the molecular actions of serotonergic antimigraine drugs

Migraine is a painful and debilitating neurological disorder that affects approximately 10% of the adult population in Western countries. Sensitization and activation of the trigeminal ganglia nerves that innervate the meningeal blood vessels is believed to play an important role in the initiation and maintenance of migraine pain. In this capacity, release of the neuropeptide calcitonin gene-related peptide (CGRP) and the resultant neurogenic inflammation is thought to underlie the pathophysiology of migraine. Largely due to the success of the serotonin Type 1 migraine drugs such as sumatriptan, migraine pathology and therapy has become a focus of intensive clinical and physiological research during the past decade. The effectiveness of these drugs is thought to be due to their ability to block the stimulated secretion of neuropeptides from trigeminal nerves to break the vicious nociceptive cycle of migraine. A component of this nociceptive cycle involves activation of mitogen-activated protein kinase signaling pathways. Indeed, activation of mitogen-activated protein kinase pathways can increase CGRP neuropeptide synthesis and secretion. Recently, the serotonin Type 1 agonists have been shown to cause a prolonged increase in intracellular Ca(2+) in trigeminal ganglia neurons and an increased phosphatase activity that can repress stimulated CGRP secretion and transcription. Identification of molecular signaling events in migraine pathology and therapy has provided new insight into the pharmacology and signaling mechanisms of sumatriptan and related drugs, and may provide the foundation for development of novel treatments for migraine.

Is the 5-HT(7) receptor involved in the pathogenesis and prophylactic treatment of migraine?

The mechanisms underlying the pathogenesis of migraine and their possible association with serotonin (5-hydroxytryptamine; 5-HT) have not yet been elucidated. One of the major obstacles in achieving this goal is the lack of information on the mechanisms by which the monoamine could possibly trigger and/or modulate the basic pathophysiological features of the condition, that is, cranial vasodilatation and neurogenic inflammation. This information should provide a useful theoretical framework to insight the nature of the postulated fundamental triggering mechanism in the brain that ultimately results in head pain. Novel avenues for research and drug development may be envisaged upon the recent observations showing that 5-HT is actually able to produce vasodilatation of intra- and extra-cranial blood vessels through a mechanism pharmacologically resembling the 5-HT(7) receptor type, and that the messenger RNA (mRNA) encoding for this receptor is highly expressed in cranial vessels. Other lines of evidence have suggested that the 5-HT(7) receptor may play an excitatory role in neuronal systems and that it may be involved in hyperalgesic pain and neurogenic inflammation. On the basis of these observations, it is proposed that the 5-HT(7) receptor may well represent a link between the abnormal phenomena of 5-HT processing and neurotransmission that are observed in migraine patients, and the vascular and neurogenic alterations that account for migraine headache. This view is supported by the fact that most of the migraine prophylactic 5-HT receptor antagonists display relatively high affinity for the 5-HT(7) receptor, which significantly correlates with their pharmaceutically active oral doses.

Effects of donitriptan on carotid haemodynamics and cardiac output distribution in anaesthetized pigs

We investigated the effects of donitriptan, which possesses a uniquely high affinity and efficacy at 5-HT1B/1D receptors, on carotid and systemic haemodynamics in anaes thetized pigs. Donitriptan (0.16-100 microg kg(-1), i.v.) dose-dependently decreased total carotid blood flow and vascular conductance (maximum response: -25 +/- 3%). This effect was entirely due to a selective reduction in the cephalic arteriovenous anastomotic fraction (maximum response: - 63 +/- 3%; ED50%: 92 +/- 31 nmol/kg); the nutrient vascular conductance increased. Donitriptan did not decrease vascular conductances in or blood flow to a number of organs, including the heart and kidneys; in fact, vascular conductances in the skin, brain and skeletal muscles increased. Cardiac output was slightly decreased by donitriptan, but this effect was confined to peripheral arteriovenous anastomoses. The haemodynamic effects of donitriptan were substantially reduced by the 5-HT1B/1D receptor antagonist GR127935. These results show that donitriptan selectively constricts arteriovenous anastomoses via 5-HT1B receptor activation. The drug should be able to abort migraine headaches and it is unlikely to compromize blood flow to vital organs.

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.

Oral triptans (serotonin 5-HT(1B/1D) agonists) in acute migraine treatment: a meta-analysis of 53 trials

BACKGROUND

The triptans, selective serotonin 5-HT(1B/1D) agonists, are very effective acute migraine drugs with a well- developed scientific rationale. Seven different triptans will soon be clinically available, making evidence-based selection guidelines necessary. Triptan trials have similar designs, facilitating meta-analysis; this will provide a foundation for using triptans in clinical practice.

METHOD

We asked pharmaceutical companies and the principal investigators of company-independent trials for raw patient data of all double-blind, randomised, controlled, clinical trials of oral triptans in migraine. We calculated summary estimates across studies for important efficacy and tolerability parameters, and separately summarised direct comparator trials.

RESULTS

53 clinical trials (12 unpublished) involving 24089 patients, met the criteria for inclusion. Mean results for 100 mg sumatriptan were 59% (95% CI 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 of three treated attacks); placebo-subtracted proportions for patients with at least one adverse event (AE) were 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, 10 mg rizatriptan showed better efficacy and consistency, and similar tolerability; 80 mg eletriptan showed better efficacy, similar consistency, but lower tolerability; 12.5 mg almotriptan showed similar efficacy at 2 h but better other results; 2.5 mg naratriptan and 20 mg eletriptan showed lower efficacy and (the first two) better tolerability; 2.5 mg and 5 mg zolmitriptan, 40 mg eletriptan, and 5 mg rizatriptan showed 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 lower efficacy.

INTERPRETATION

At marketed doses, all oral triptans were effective and well tolerated. 10 mg rizatriptan, 80 mg eletriptan, and 12.5 mg almotriptan provide the highest likelihood of consistent success.

Sumatriptan responsiveness and clinical, psychiatric and psychologic features in migraine patients

OBJECTIVE

To compare sumatriptan responders and nonresponders in a migraine population with regard to a number of clinical, psychiatric and psychologic features.

METHODS

Patients were drawn from a referral headache clinic population, and classified as responders or nonresponders. Clinical features were assessed by a written questionnaire. The lifetime prevalence of several psychiatric disorders was determined by the National Institute of Mental Health diagnostic interview schedule and personality factors were measured by the 16 Personality Factors (16PF) Questionnaire.

RESULTS

Nonresponders indicated less influence on their migraine by menstrual factors, had a higher lifetime prevalence of generalized anxiety, and showed 16PF scores indicating greater shyness, self-sufficiency and perfectionism. Nonresponders were also more imaginative and less socially outgoing.

CONCLUSION

Although they must be interpreted with caution due to small sample size and the multiple comparisons made, our results indicate that there may be differences between sumatriptan responders and nonresponders with regard to a number of clinical, psychiatric and psychologic factors. These results suggest that biological differences exist between the two patient groups which likely account for both the differences in their responses to sumatriptan and in the clinical features noted above.

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.

A comparison of visual analog scale and categorical ratings of headache pain in a randomized controlled clinical trial with migraine patients

A visual analog scale (VAS) method of assessing headache pain was compared with a standard categorical four-grade scale (4GS) in a randomized, placebo-controlled, double-blind, clinical trial involving 792 treated migraine outpatients who received oral rizatriptan 5 mg, sumatriptan 50 mg, or placebo for a moderate or severe headache. The VAS and 4GS were equally useful in demonstrating that the active drugs were superior to placebo at reducing headache pain, and in showing that the active drugs were similarly effective. For both rizatriptan and sumatriptan, slightly larger effect sizes were observed with the 4GS compared with the VAS. In analyses using data combined across all treatment groups, VAS and 4GS scores were highly correlated. Use of the VAS imposed additional administrative burdens. These findings suggest that the 4GS may be the preferred scale for assessing headache pain in clinical trials involving adult migraineurs.

The lack of vasoconstrictor effect of the pineal hormone melatonin in an animal model predictive of antimigraine activity

The pineal hormone, melatonin, has been implicated in the pathophysiology of migraine and several studies have demonstrated its vasoconstrictor properties. In the present study, systemic and carotid haemodynamic effects of melatonin, administered directly into the carotid artery, were investigated in anaesthetized pigs. Ten-minute intracarotid infusions of melatonin (1, 10 and 100 microg kg(-1) min(-1)) produced slight decreases in blood pressure and total carotid and arteriovenous anastomotic blood flows, but nutrient blood flow was not affected. The decrease in carotid blood flow was entirely caused by the hypotension, since no changes in vascular conductance values were observed. It is concluded that melatonin itself is not capable of producing vasoconstriction in the cranial circulation of anaesthetized pigs. Thus, it appears that melatonin has no anti-migraine potential via a vasoconstrictor mechanism.

The efficacy and safety of sc alniditan vs. sc sumatriptan in the acute treatment of migraine: a randomized, double-blind, placebo-controlled trial

This double-blind, placebo-controlled, parallel-group, multicentre, multinational, phase-III trial was designed to assess the efficacy and safety of a single subcutaneous injection of placebo, 2 doses of alniditan (1.4 mg and 1.8 mg) and 6 mg of sumatriptan in subjects with acute migraine. A total of 114 investigators from 13 different countries screened 2021 subjects. In total 924 patients were treated with placebo (157), alniditan 1.4 mg (309), alniditan 1.8 mg (141) and sumatriptan 6 mg (317). The lower number of subjects in the alniditan 1.8 mg group is due to the termination of this trial arm after the incidence of a serious adverse event and a subsequent protocol amendment. The number of subjects who were pain free at 2 h (primary endpoint) was: 22 (14.1%) with placebo, 174 (56.3%) with alniditan 1.4 mg, 87 (61.7%) with alnditan 1.8 mg and 209 (65.9%) with sumatriptan 6 mg. Alniditan 1.4 mg was significantly better (P < 0.001) than placebo and sumatriptan was significantly better (P = 0.015) than alniditan 1.4 mg. The number of responders (reduction of headache severity from moderate or severe headache before treatment to mild or absent at 2 h), was 59 (37.8%) on placebo, 250 (80.9%) on alniditan 1.4 mg, 120 (85.1%) on alniditan 1.8 mg, and 276 (87.1%) on sumatriptan. Response was significantly higher (P < 0.001) with alniditan 1.4 mg than with placebo, and significantly lower (P = 0.036) with alniditan 1.4 mg than with sumatriptan. Recurrence rates were: 22 (37.3%) with placebo, 87 (34.8%) with alniditan 1.4 mg, 35 (29.2%) with alniditan 1.8 mg and 108 (39.1%) with sumatriptan. Adverse events occurred in 577/924 (62.4%) subjects, i.e. in 62/157 (39.5%) with placebo, 214/309 (69.3%) with alniditan 1.4 mg, 91/141 (64.5%) with alniditan 1.8 mg and 210/317 (66.2%) with sumatriptan 6 mg. Sumatriptan was significantly better than alniditan 1.4 mg for pain free at 2 h. The difference, however, was small and clinically not important. For alniditan, a dose-dependent adverse event relationship was seen. The safety profile of alniditan 1.4 mg was similar to that of sumatriptan.

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.

The trigeminovascular system in bacterial meningitis

Headache as a cardinal symptom of acute meningitis reflects activation of trigeminal afferents from the meninges. With their perivascular endings, these fibers form the so-called trigeminovascular system (TVS), which releases proinflammatory neuropeptides upon nociceptive stimulation. In the present article, we review a role of the TVS in enhancing the early inflammatory response of bacterial meningitis. Furthermore, we discuss inhibition of neuropeptide release from the TVS using 5HT(1B/D) agonists as a potential new anti-inflammatory treatment strategy for early bacterial meningitis.

The challenge of evidence-based migraine therapy

It is important that physicians practise evidence-based medicine. Clinical experience is important, but there are a number of reasons why clinical experience can lead to the impression that ineffective treatments are effective. There are major educational and research challenges which must be met before clinicians can practice evidence-based migraine therapy more extensively than at present. Treating physicians will need to learn more about the principles of evidence-based medicine. Researchers will need to produce more and better clinical trials that address important clinical questions. The results of these trials will need to be reported clearly, and we need to improve the efficiency with which these results can be accessed. It is important that the pharmaceutical industry, clinicians, and academic health centres work together to meet these challenges.

5-HT7 receptor mRNA expression in human trigeminal ganglia

The present study investigated, by using the method of reverse transcriptase polymerase chain reaction, whether the 5-HT7 receptor mRNA is expressed in human trigeminal ganglia. Trigeminal ganglia were excised post mortem from five human subjects. Oligonucleotide primers were selected based upon unique regions of complementary DNA sequence for the cloned human 5-HT7 receptor. Sequence analysis revealed the presence of a single message that matched the sequence of the cloned human 5-HT7 receptor. The present results may direct future efforts to determine the potential excitatory role of the 5-HT7 receptor in the neuropathological events that develop in migraine headache.

Treatment of childhood headaches

Migraine and tension-type headaches are two of the most common types of primary headache disorders in children. Migraine is a primary central nervous system disorder characterized by triggered or spontaneous episodes of activation of trigemino-vascular complex, neurogenic inflammation around vessels and meninges, and stimulation of the peripheral and central pain pathways of the trigemino-cervical complex. The triptans, by their selective agonistic action on 5-HT1B/1D receptors, are very effective in the treatment of migraine pain and associated symptoms. Early studies on the safety and efficacy of triptans in the management of childhood migraine show encouraging results. We propose a stratified-care model for the management of migraine in children, and discuss pharmacotherapy based on the pathophysiologic mechanisms of migraine pain. Management of tension-type headaches requires comprehensive medical and psychologic evaluation and an individualized approach for a successful outcome.

Comparative effects of frovatriptan and sumatriptan on coronary and internal carotid vascular haemodynamics in conscious dogs

The effects of frovatriptan and sumatriptan on internal carotid and coronary vascular haemodynamics were investigated and compared in conscious dogs. Frovatriptan and sumatriptan (0.1 - 100 microg kg(-1)) induced a transient increase in external coronary artery diameter (eCOD) of up to 2.9+/-1.2 and 1.8+/-0.6%, respectively (both P:<0.05). This was followed by a prolonged and dose-dependent decrease in eCOD of up to -5.2+/-1.2 and -5.3+/-0.9% (both P:<0.05), with ED(50) values of 86+/-21 and 489+/-113 micromol kg(-1), respectively. In contrast, only a decrease in the external diameter of the internal carotid artery was observed (-6.0+/-0.6 and -6.2+/-1.4%, both P:<0.05, and ED(50) values of 86+/-41 and 493+/-162 micromol kg(-1), respectively). Frovatriptan was thus 5.7 fold more potent than sumatriptan at the level of both large coronary and internal carotid arteries. After endothelium removal by balloon angioplasty in coronary arteries, the initial dilatation induced by the triptans was abolished and delayed constriction enhanced. The selective antagonist for the 5-HT(1B) receptors SB224289 dose-dependently blocked the effects of sumatriptan on large coronary and internal carotid arteries whereas the selective antagonist for the 5-HT(1D) receptors BRL15572 did not affect any of these effects. In conclusion, frovatriptan and sumatriptan initially dilate and subsequently constrict large coronary arteries in the conscious dog, whereas they directly constrict the internal carotid artery. The vascular endothelium modulates the effects of these triptans on large coronary arteries. Finally, 5-HT(1B) but not 5-HT(1D) receptors are primarily involved in canine coronary and internal carotid vasomotor responses to sumatriptan.

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.

The impact of pharmacogenetics for migraine

Migraine is a paroxysmal neurological disorder affecting up to 12% of males and 24% of females in the general population. As migraine has been demonstrated to have a strong, but complex, genetic component, pharmacogenetics bears great promise in providing new targets for drug development and optimization of individual specific therapy. Better, preferably prophylactic, treatment of migraine patients is desired because the drugs now used are not effective in all patients, allow recurrence of the headache in a high percentage of patients and sometimes have severe adverse side-effects. With the recent identification of the brain-specific P/Q-type Ca(2+)channel gene CACNA1A as a pivotal player in the pathogenesis of migraine, the first step has been taken to identify primary biochemical pathways leading to migraine. The work on migraine can also have implications for the increasing number of additional neurological episodic disorders having the common denominator of channelopathy.

Efficacy of intravenous magnesium sulfate in the treatment of acute migraine attacks

OBJECTIVE

To study the efficacy and tolerability of 1 g of intravenous magnesium sulfate as acute treatment of moderate or severe migraine attacks.

BACKGROUND

Migraine is a common disorder in which not only the pain but also the accompanying symptoms such as nausea and vomiting reduce activity and productivity of sufferers. Many drugs used for the treatment of acute migraine attacks have many side effects, are not well tolerated, are ineffective in some patients, or cannot be used during pregnancy or in patients with ischemic heart disease. Magnesium deficiency has been proposed to play a role in the pathophysiology of migraine, and recently treatment of migraine with magnesium has gained considerable interest.

METHODS

This was a randomized, single-blind, placebo-controlled trial including 30 patients with moderate or severe migraine attacks. Fifteen patients received 1 g intravenous magnesium sulfate given over 15 minutes. The next 15 patients received 10 mL of 0.9% saline intravenously. Those in the placebo group with persisting complaints of pain or nausea and vomiting after 30 minutes also received 1 g magnesium sulfate intravenously over 15 minutes. The patients were assessed immediately after treatment, and then 30 minutes and 2 hours later. Intensity of pain, accompanying symptoms, and side effects were noted.

RESULTS

All patients in the treatment group responded to treatment with magnesium sulfate. The pain disappeared in 13 patients (86.6%); it was diminished in 2 patients (13.4%); and in all 15 patients (100%), accompanying symptoms disappeared. In the placebo group, a decrease in pain severity but persisting nausea, irritability, and photophobia were noted in 1 patient (6.6%). Accompanying symptoms disappeared in 3 patients (20%) 30 minutes after placebo administration. All patients initially receiving placebo were subsequently given magnesium sulfate. All of these patients responded to magnesium sulfate. In 14 patients (93.3%), the attack ended; in 1 patient (6.6%), pain intensity decreased; and in all 15 patients (100%), accompanying symptoms disappeared. Both the response rate (100% for magnesium sulfate and 7% for placebo) and the pain-free rate (87% for magnesium sulfate and 0% for placebo) showed that magnesium sulfate was superior to placebo. Twenty-six patients (86.6%) had mild side effects which did not necessitate discontinuing treatment during magnesium sulfate administration.

CONCLUSION

Our results show that 1 g intravenous magnesium sulfate is an efficient, safe, and well-tolerated drug in the treatment of migraine attacks. It is possible that magnesium sulfate could be used in a broader spectrum of patients than other drugs commonly used for attack treatment. In view of these results, the effect of magnesium sulfate in acute migraine should be examined in large-scale studies.

A systematic review of the use of triptans in acute migraine

OBJECTIVE

A systematic review of the literature was undertaken, to consolidate evidence concerning the efficacy and safety of triptans currently available in Canada (sumatriptan, rizatriptan, naratriptan, zolmitriptan), and to provide guidelines for selection of a triptan.

METHODS

Data from published, randomized, placebo-controlled trials were pooled and a combined number needed to treat (NNT) and number needed to harm (NNH) was generated for each triptan. Direct comparative trials of triptans were also examined.

RESULTS

The lowest NNT for headache response/pain-free at one/two hours is observed with subcutaneous sumatriptan. Among the oral formulations, the lowest NNT is observed with rizatriptan and the highest NNT with naratriptan. The lowest NNH is observed with subcutaneous sumatriptan.

CONCLUSIONS

Triptans are relatively safe and effective medications for acute migraine attacks. However, differences among them are relatively small. Considerations in selecting a triptan include individual patient response/tolerance, characteristics of the attacks, relief of associated symptoms, consistency of response, headache recurrence, delivery systems and patient preference.

Sumatriptan: pharmacological basis and clinical results

Sumatriiptan was the first selective serotonin (5-HT)1B/1D agonist for the acute treatment of migraine attacks. Apart from the subcutaneous and oral formulation, it is also available as nasal spray and suppository. In placebo-controlled clinical trials, sumatriptan, administered subcutaneously, orally, intranasally or rectally was significantly more effective than placebo in relieving migraine headache and in producing relief or resolution of other symptoms associated with migraine, including nausea, photophobia and phonophobia. For patients who desire particularly rapid relief that cannot be provided by a tablet form, sumatriptan injection with a 10-minute onset of action may be an appropriate choice. Patients with very severe attacks and those with vomiting may also benefit from the injection. For patients with nausea who do not wish to take tablets or who fear injections, a sumatriptan nasal spray or a suppository may be appropriate options. New triptans, zolmitriptan, rizatriptan, and naratriptan began entering the market in 1997 but in clinical practice, in particular after dose adjustments have been made, all triptans appear to be very similar with respect to efficacy and tolerability as well as safety.

Hypothesized treatment for migraines using low doses of tryptophan, niacin, calcium, caffeine, and acetylsalicylic acid

The author hypothesized that existing agents known to influence serotonin blood level, vascular tone, and inflammatory reactions might terminate migraines. The author presented the rationale for using five different agents therapeutically and avoiding two other agents during a migraine. The proposed treatment is to use low doses of tryptophan, niacin, calcium, caffeine, and acetylsalicylic acid (ASA) soon after migraine symptoms are noticed and to avoid during a migraine high-potassium food and magnesium supplements. Preliminary results from 12 migraine patients indicated that 9 of 12 (75%) had significant benefit from this approach. Using these five agents together is a novel combination and a new idea for treating migraines.

The pharmacology of headache

Headache is a common problem which besets most of us at some time or the other. The pharmacology of headache is complex in an overall sense but can be understood in terms of the anatomy and physiology of the pain-producing structures. Migraine can be used as a template to understand the activation of nociceptive systems in the head and thus their neurotransmitter mediation and modulation. In recent years, the role of serotonin (5-HT) in headache pharmacology has been unravelled in the context of both understanding its role in the nociceptive systems related to headache and by exploiting its 5-HT1 receptor subtypes in headache therapeutics. The pharmacology of the head pain systems, as they are known and as they might evolve, are explored in the context of both, the anatomy and physiology of trigeminovascular nociception and in the context of clinical questions, such as those of efficacy, headache recurrence and adverse events.

Triptans in migraine: a comparative review of pharmacology, pharmacokinetics and efficacy

Triptans are a new class of compounds developed for the treatment of migraine attacks. The first of the class, sumatriptan, and the newer triptans (zolmitriptan, naratriptan, rizatriptan, eletriptan, almotriptan and frovatriptan) display high agonist activity at mainly the serotonin 5-HT1B and 5-HT1D receptor subtypes. As expected for a class of compounds developed for affinity at a specific receptor, there are minor pharmacodynamic differences between the triptans. Sumatriptan has a low oral bioavailability (14%) and all the newer triptans have an improved oral bioavailability and for one, risatriptan, the rate of absorption is faster. The half-lives of naratriptan, eletriptan and, in particular, frovatriptan (26 to 30h) are longer than that of sumatriptan (2h). These pharmacokinetic improvements of the newer triptans so far seem to have only resulted in minor differences in their efficacy in migraine. Double-blind, randomised clinical trials (RCTs) comparing the different triptans and triptans with other medication should ideally be the basis for judging their place in migraine therapy. In only 15 of the 83 reported RCTs were 2 triptans compared, and in 11 trials triptans were compared with other drugs. Therefore, in all placebo-controlled randomised clinical trials, the relative efficacy of the triptans was also judged by calculating the therapeutic gain (i.e. percentage response for active minus percentage response for placebo). The mean therapeutic gain with subcutaneous sumatriptan 6mg (51%) was more than that for all other dosage forms of triptans (oral sumatriptan 100mg 32%; oral sumatriptan 50mg 29%: intranasal sumatriptan 20mg 30%; rectal sumatriptan 25mg 31%; oral zolmitriptan 2.5mg 32%; oral rizatriptan 10mg 37%; oral eletriptan 40mg 37%; oral almotriptan 12.5mg 26%). Compared with oral sumatriptan 100mg (32%), the mean therapeutic gain was higher with oral eletriptan 80mg (42%) but lower with oral naratriptan 2.5mg (22%) or oral frovatriptan 2.5mg (16%). The few direct comparative randomised clinical trials with oral triptans reveal the same picture. Recurrence of headache within 24 hours after an initial successful response occurs in 30 to 40% of sumatriptan-treated patients. Apart from naratriptan, which has a tendency towards less recurrence, there appears to be no consistent difference in recurrence rates between the newer triptans and sumatriptan. Rizatriptan with its shorter time to maximum concentration (tmax) tended to produce a quicker onset of headache relief than sumatriptan and zolmitriptan. The place of triptans compared with non-triptan drugs in migraine therapy remains to be established and further RCTs are required.

A randomized, double-blind, placebo-controlled study of sumatriptan nasal spray in the treatment of acute migraine in adolescents

OBJECTIVE

To compare the efficacy and tolerability of sumatriptan nasal spray (NS; 5 mg, 10 mg, and 20 mg) with placebo for the treatment of acute migraine in adolescents.

METHODS

A randomized, double-blind, placebo-controlled, single-attack study was conducted in 653 US adolescents (12-17 years of age). Patients with at least a 6-month history of migraine, who met International Headache Society criteria for migraine (with or without aura) were eligible for participation. Headache relief 2 hours postdose, complete relief, presence or absence of associated symptoms, headache recurrence, and use of rescue medications were recorded. The primary efficacy endpoint was headache relief 2 hours postdose sumatriptan NS (20 mg) versus placebo. Safety and tolerability were assessed by examining adverse events, changes in electrocardiograms, vital signs, physical examinations, and clinical laboratory tests.

RESULTS

Headache relief 1 hour postdose was significantly greater for patients using 10 mg (56%) and 20 mg (56%) of sumatriptan NS compared with placebo (41%). Headache relief 2 hours postdose was significantly greater for patients using 5 mg of sumatriptan NS (66%) compared with placebo (53%), and approached statistical significance for 20 mg (63%) compared with placebo (53%). Complete relief 2 hours postdose was significantly greater for patients using 20 mg of sumatriptan NS compared with placebo (36% vs 25%, respectively). Each dose of sumatriptan (5 mg, 10 mg, and 20 mg) was superior to placebo with respect to the cumulative percentages of patients first reporting headache relief within 2 hours of dosing (Kaplan-Meier). The sumatriptan 20-mg dose was superior to placebo with respect to the cumulative percentages of patients first reporting complete relief within 2 hours of dosing (Kaplan-Meier). Photophobia and phonophobia were significantly reduced 2 hours postdose for sumatriptan NS (20 mg), compared with placebo (36% vs 48% and 25% vs 44%, respectively). Taste disturbance was the most commonly reported adverse event (2%, 19%, 30%, and 26% for placebo, 5 mg, 10 mg, and 20 mg, respectively). No drug-related serious adverse events or clinically relevant changes in laboratory parameters, electrocardiograms, or vital signs were reported.

CONCLUSIONS

Sumatriptan NS is effective and well-tolerated for the treatment of acute migraine in adolescents, with the 20-mg dose providing the best overall efficacy and tolerability profiles.

Migraine: pharmacotherapy in the emergency department

Migraine can be a disabling condition for the sufferer. For the small number of patients for whom home therapy fails and who seek treatment in an emergency department, several therapeutic options are available. I review the evidence regarding the effectiveness and safety of the following therapies: the phenothiazines, lignocaine (lidocaine), ketorolac, the ergot alkaloids, metoclopramide hydrochloride, the "triptans," haloperidol, pethidine (meperidine hydrochloride), and magnesium sulfate. Based on available evidence, the most effective agents seem to be prochlorperazine, chlorpromazine and sumatriptan, each of which has achieved greater than 70% efficacy in several studies.

Providing relief from headache pain. Current options for acute and prophylactic therapy

The sometimes debilitating pain of migraine and other types of primary headache can be difficult to control with acute drug therapy alone. Often patients need both acute and prophylactic treatment to keep headache pain at bay. Dr Ward discusses the current treatment options for migraine with and without aura, tension-type headache, and cluster headache. He also provides practical pointers for use of the various formulations of specific drugs, including the newer "triptan" medications.

Efficacy of naratriptan tablets in the acute treatment of migraine: a dose-ranging study. Naratriptan S2WB2004 Study Group

OBJECTIVE

This study sought to compare the efficacy of several doses of naratriptan tablets with that of sumatriptan tablets and placebo in the acute treatment of a single migraine attack.

METHODS

This was a randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study. Patients received either naratriptan tablets (1, 2.5, 5, 7.5, or 10 mg), sumatriptan tablets (100 mg), or placebo.

RESULTS

A total of 643 patients took part in the study. Two hours after dosing, headache relief was reported by significantly more patients treated with any dose of naratriptan (52%-69%) or sumatriptan (60%) than with placebo (31%) (P < 0.05). Four hours after dosing, headache relief was reported by significantly more patients treated with any dose of naratriptan (63%-80%) or sumatriptan (80%) than with placebo (39%) and by significantly more patients treated with sumatriptan 100 mg (80%) than with naratriptan 1 mg (64%), 2.5 mg (63%), or 5 mg (65%) (P < 0.05). Twenty-four-hour overall efficacy (headache relief maintained through 24 hours postdose with no worsening, no use of rescue medication, and no recurrence) was reported by more patients treated with any dose of naratriptan (39%-58%) or sumatriptan (44%) than with placebo (22%). Headache recurrence was reported in 17% to 32% of naratriptan-treated patients, 44% of sumatriptan-treated patients, and 36% of placebo recipients. The overall incidence of adverse events was similar in patients treated with naratriptan 1 mg (20%), naratriptan 2.5 mg (21%), and placebo (23%). For naratriptan 5, 7.5, and 10 mg, the incidence of adverse events was 32%, 37%, and 35%, respectively, and for sumatriptan 100 mg it was 26%.

CONCLUSIONS

Our results suggest that the 2.5-mg dose of naratriptan tablets offers the optimal efficacy-to-tolerability ratio at the dose range between 1 and 10 mg. Although naratriptan 2.5 mg was less effective than sumatriptan 100 mg at 4 hours after dosing, the 2 medications showed similar efficacy at 24 hours.

Effectiveness of sumatriptan in reducing productivity loss due to migraine: results of a randomized, double-blind, placebo-controlled clinical trial

OBJECTIVE

To determine the effect of sumatriptan on migraine-related workplace productivity loss.

PATIENTS AND METHODS

In this randomized, double-blind, placebo-controlled, parallel-group trial, adult migraineurs self-injected 6 mg of sumatriptan or matching placebo to treat a moderate or severe migraine within the first 4 hours of a minimum of an 8-hour work shift. Outcome measures included productivity loss and number of patients returning to normal work performance 2 hours after injection and across the work shift, time to return to normal work performance, and time to headache relief.

RESULTS

A total of 206 patients underwent screening, 140 (safety population) of whom returned for clinic treatment. Of these 140 patients, 119 received migraine treatment in the workplace (intent-to-treat population), 116 of whom comprised the study population. Of these 116 patients, 76 self-administered sumatriptan, and 40 self-administered placebo. Sumatriptan treatment tended to reduce median productivity loss 2 hours after injection compared with placebo (25.2 vs 29.9 minutes, respectively; P = .14). Significant reductions in productivity loss were obtained across the work shift after sumatriptan treatment compared with placebo (36.8 vs 72.6 minutes, respectively; P = .001). Significantly more sumatriptan-treated patients vs placebo-treated patients experienced shorter return to normal work performance at 2 hours (53/76 [70%] vs 12/40 [30%], respectively) and across the work shift (64/76 [84%] vs 23/40 [58%], respectively; P < .001). Significantly more sumatriptan-treated patients experienced headache relief 1 hour after injection compared with placebo-treated patients (48/76 [63%] vs 13/40 [33%], respectively; P = .004).

CONCLUSION

Across an 8-hour work shift, sumatriptan was superior to placebo in reducing productivity loss due to migraine.

The in vivo pharmacological profile of eletriptan (UK-116,044): a potent and novel 5-HT(1B/1D) receptor agonist

The anti-migraine drug, eletriptan [(R)-3-(1-methyl-2-pyrrolidinylmethyl)-5-[2-(phenylsulphonyl )ethyl]-1 H-indole; UK-116,044], is a novel 5-HT(1B/1D) receptor agonist. In this paper, the regional vasoconstrictor profile of eletriptan, in comparison with sumatriptan, was examined in the anaesthetised dog. The inhibitory actions of eletriptan on neurogenic inflammation in rat dura mater were also assessed. In the anaesthetised dog, eletriptan (1-1000 microg kg(-1) i.v.) produced a dose-dependent reduction of carotid arterial blood flow with a similar potency and maximum effect to sumatriptan (ED(50) values: eletriptan and sumatriptan, 12 and 9 microg kg(-1), i.v., respectively). However, eletriptan exhibited a significantly lower potency than sumatriptan in reducing coronary artery diameter (ED(50) values: 63 and 19 microg kg(-1), i.v., respectively, P<0.05). In the femoral circulation, sumatriptan caused a significant reduction in arterial blood flow (ED(50) 35 microg kg(-1) i.v.) whereas eletriptan (1-1000 microg kg(-1) i.v.) had no significant effect upon femoral arterial blood flow when compared to vehicle-treated animals. In rats, eletriptan (30-300 microg kg(-1) i.v.) administered prior to electrical stimulation of the trigeminal ganglion produced a dose-related and complete inhibition of plasma protein extravasation in the dura mater (mean extravasation ratio: control 1.9; eletriptan 1.0, minimum effective dose 100 microg kg(-1), P<0.05). The potency and maximum effect of eletriptan was identical to that of sumatriptan in this model. When administered during a period of continual stimulation of the trigeminal nerve, eletriptan (100 microg kg(-1) i.v.) produced a complete inhibition of plasma protein extravasation. The ability to reduce canine carotid arterial blood flow and inhibit neurogenic inflammation in rat dura mater suggests that vascular and neurogenic mechanisms may contribute to eletriptan's clinical efficacy in migraine patients. In addition, eletriptan exhibits some selectivity for reducing carotid arterial blood flow when compared with femoral arterial blood flow and coronary artery diameter, in the anaesthetised dog.

Sumatriptan in patients with postdural puncture headache

OBJECTIVE

To determine the efficacy of sumatriptan in the management of patients presenting for an epidural blood patch for the management of postdural puncture headache.

BACKGROUND

Postdural puncture headache can be quite severe, requiring invasive therapy (ie, epidural blood patch). Sumatriptan has been used successfully in patients with postdural puncture headache, however, its use has not been investigated in a controlled fashion.

METHODS

Ten patients with postdural puncture headache presenting for an epidural blood patch were given either saline or sumatriptan subcutaneously. The severity of the headache was evaluated at baseline and 1 hour following injection. If the headache remained severe, an epidural blood patch was performed.

RESULTS

Only one patient in each group received relief from the injection.

CONCLUSIONS

We do not recommend sumatriptan in patients who have exhausted conservative management of postdural puncture headache.

Sumatriptan nasal spray in the acute treatment of migraine: a review of clinical studies

Sumatriptan nasal spray is a single-dose device that delivers 5 mg, 10 mg, or 20 mg of sumatriptan (dosage availability dependent upon country) in a 0.1 ml aqueous solution to one nostril. The efficacy and tolerability of sumatriptan nasal spray have been assessed in a number of studies. It has been demonstrated that administering sumatriptan as a divided dose in both nostrils confers no advantage over administration in a single nostril. It appears from these studies that sumatriptan nasal spray is rapidly effective (with an onset of efficacy as early as 15 min postdose). The 20 mg dose is superior to the lower doses (5 mg, 10 mg) in terms of both time to onset of efficacy and the extent of migraine symptom relief. Sumatriptan nasal spray is consistently effective in the treatment of multiple migraine attacks (with 67% of patients treated with the 20 mg dose responding in at least two of three treated attacks) and with long-term use for up to 1 year. Apart from a bitter taste, the adverse event profile of sumatriptan nasal spray is comparable to that of placebo.

Use and overuse of sumatriptan. Pharmacoepidemiological studies based on prescription register and interview data

The serotonin agonist sumatriptan was marketed in Denmark in 1992 for the treatment of acute attacks of migraine and cluster headache. The clinical development program of the drug was impressive. However, knowledge of the long-term use of sumatriptan in unselected patients was lacking. Misuse of sumatriptan was reported in single patients shortly after the introduction of the drug. The aim of the present thesis was, therefore, to provide an epidemiological description of sumatriptan use with particular emphasis on overuse. The author conducted three studies, two of which were exclusively based on population-based data from a regional (Odense Pharmacoepidemiological Database) and a national (Registry of Drug Statistics, Danish Medicines Agency) prescription registry. Both registries record patient-specific information, thus enabling the conduct of longitudinal studies of drug use. The regional registry covers the county of Funen (reimbursable prescription drugs only), while the national registry records information on all prescriptions presented in the entire country. Consumption was described by means of the Defined Daily Dose (DDD) unit. One DDD of sumatriptan amounts to 100 mg orally or 6 mg subcutaneously. Subjects were classified as recipients of single or multiple prescriptions. Individuals in the latter category were characterized by the 30-day period with the most intensive dispensing of sumatriptan (peak use): low (less than 30 DDD/30 days), intermediate (30-59 DDD/30 days) and high-peak users (60 or more DDD/30 days). In 1995, 33,206 users of sumatriptan were identified in Denmark, corresponding to a 1-year period prevalence of use of 7.8 per 1,000 inhabitants (only persons aged > or = 16 years were included). A female-to-male ratio of 3.8:1 was found. Use was most common among women aged 35-54 years and was highest among 45 to 49-year-olds for both sexes. The standardized period prevalence of sumatriptan use varied regionally between the Danish counties from 6.4 to 9.6 per 1,000 inhabitants. The period prevalence of sumatriptan use in the county of Funen was highly comparable with that of the entire nation. Among the 43,389 sumatriptan users presenting prescriptions for sumatriptan in Denmark in 1994 and 1995, 507 (1.1%) and 1726 (4.0%) belonged to the high and intermediate-peak-use group, respectively. Patients belonging to these two groups were responsible for 38% of the total consumption of sumatriptan. For patients in the high-peak-use group the median span between first and last prescription was 693 days while the median quantity of sumatriptan purchased was 648 DDD. Highly comparable patterns of long-term intense sumatriptan use were found in the data from the regional registry, which covered the 27-month period after the introduction of the drug (February 1992). The register data were highly suggestive of overuse, but lacked essential information, e.g., the indication for use. A third study was therefore conducted using a combination of register and interview data. During a 14-day period, current users of sumatriptan were recruited through community pharmacies in the county of Funen. Respondents returned a signed consent form, including their unique personal identification number (CPR), allowing us to retrieve patient-specific data from the regional registry. For each respondent, all available relevant prescription data for the period 1992-96 were retrieved. Subjects were classified into high, intermediate, and low-peak-use groups according to register data from the 4-year period. The register data were used to evaluate representativity after anonymizing nonrespondent data. The response rates were 33% (7/21) in the high-peak-use group, 47% (30/64) in the intermediate-peak-use group, and 56% (196/350) in the low-peak-use group. Respondents and nonrespondents in the three groups were comparable with regard to age and use of other drugs. (ABSTRACT TRUNCATED)

Changes in systolic time intervals-a non-invasive marker for the haemodynamic effects of sumatriptan

AIMS

This study assessed the use of systolic time intervals (STI) as a potential non-invasive marker of the haemodynamic effects of sumatriptan, a 5HT1 receptor agonist.

METHODS

Twenty-six patients undergoing diagnostic cardiac catheterization participated. STIs were derived from haemodynamic pressure tracings at baseline, following placebo injection and following either subcutaneous (n=18) or intravenous injection (n=8) of sumatriptan.

RESULTS

Sumatriptan (i.v. or s.c.) was associated with significant increases in mean arterial pressure (95% C.I. 9,14mmHg, P=0.0001), total electromechanical systole (95% C.I.8,36ms, P<0.0001), pre-ejection period (95%C.I. 8,21ms, P=0.0001) and left ventricular ejection time (95% C.I. 2,12ms, P=0.004). Conclusion STI responses were consistent with sumatriptan-induced changes in afterload. In summary, the measurement of STIs is a potential non-invasive method of investigating the influence of serotonergic compounds on the cardiovascular system.