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

Diagnosis and management of the primary headache disorders in the emergency department setting

Headache continues to be a frequent cause of emergency department (ED) use, accounting for 2% of all visits. Most of these headaches prove to be benign but painful exacerbations of chronic headache disorders, such as migraine, tension-type, and cluster. The goal of ED management is to provide rapid and quick relief of benign headache, without causing undue side effects, and to recognize headaches with malignant course. Although these headaches have distinct epidemiologies and clinical phenotypes, there is overlapping response to therapy; nonsteroidals, triptans, dihydroergotamine, and the antiemetic dopamine antagonists may play a therapeutic role for each of these acute headaches. This article reviews the diagnostic criteria and management strategies for the primary headache disorders.

Efficacy and tolerability of MK-0974 (telcagepant), a new oral antagonist of calcitonin gene-related peptide receptor, compared with zolmitriptan for acute migraine: a randomised, placebo-controlled, parallel-treatment trial

BACKGROUND

Calcitonin gene-related peptide (CGRP) probably has a role in migraine pathophysiology, and antagonism of its receptors might provide treatment without the vasoconstrictor effects of triptans. We aimed to assess the clinical profile of MK-0974 (telcagepant), an orally bioavailable antagonist of CGRP receptor.

METHODS

In a randomised, parallel-treatment, placebo-controlled, double-blind, trial at 81 sites in the Europe and the USA, adults with migraine diagnosed by International Headache Society criteria treated moderate or severe attacks with either oral telcagepant 150 mg or 300 mg, zolmitriptan 5 mg, or placebo. The five co-primary endpoints were pain freedom, pain relief, or absence of photophobia, phonophobia, or nausea at 2 h after treatment. Analysis was by the full analysis set and multiplicity was controlled for with a step-down closed-testing procedure. This trial is registered with ClinicalTrials.gov, number NCT00442936.

FINDINGS

1380 patients were randomly assigned to receive telcagepant 150 mg (n=333) or 300 mg (354), zolmitriptan (345), or placebo (348). Telcagepant 300 mg was more effective than placebo for pain freedom (95 [27%] of 353 patients vs 33 [10%] of 343 [p<0.0001]), pain relief (194 [55%] of 353 vs 95 [28%] of 343 [p<0.0001]), and absences of phonophobia (204 [58%] of 353 vs 126 [37%] of 342 [p<0.0001]), photophobia (180 [51%] of 353 vs 99 [29%] of 342 [p<0.0001]), and nausea (229 [65%] of 352 vs 189 [55%] of 342 [p=0.0061]). Efficacy of telcagepant 300 mg and zolmitriptan 5 mg were much the same, and both were more effective than telcagepant 150 mg. Adverse events were recorded for 31% taking telcagepant 150 mg, 37% taking telcagepant 300 mg, 51% taking zolmitriptan 5 mg, and 32% taking placebo.

INTERPRETATION

Telcagepant 300 mg is effective as an acute treatment for migraine with efficacy comparable to that of zolmitriptan 5 mg, but with fewer associated adverse effects.

FUNDING

Merck Research Laboratories.

Examining the binding properties of MK-0974: a CGRP receptor antagonist for the acute treatment of migraine

Calcitonin gene-related peptide (CGRP) is a neuropeptide that plays a key role in the pathophysiology of migraine headache. MK-0974 (telcagepant) is a potent and selective antagonist of the human and rhesus CGRP receptors and is currently in Phase III clinical studies for the acute treatment of migraine. The pharmacology of MK-0974 has been studied extensively, but there has not been a thorough characterization of its binding properties. Here, we characterize the binding of a tritiated analog of MK-0974 on human neuroblastoma (SK-N-MC) membranes and rhesus cerebellum. [(3)H]MK-0974 displayed reversible and saturable binding to both SK-N-MC membranes and rhesus cerebellum with a K(D) of 1.9 nM and 1.3 nM, respectively. Agonists and antagonists of the CGRP receptor displaced [(3)H]MK-0974 in a concentration-dependent manner in competition binding experiments. Both CGRP and adrenomedullin demonstrated biphasic competition while MK-0974 and the peptide antagonist CGRP(8-37) displaced [(3)H]MK-0974 in a monophasic fashion. In competitive binding studies with [(3)H]MK-0974 and CGRP, the fraction of high-affinity binding was reduced significantly by incubating the membranes with GTPgammaS. In kinetic binding experiments, the off-rate of [(3)H]MK-0974 was determined to be 0.51 min(-1) with a half-life of 1.3 min. In conclusion, the radioligand [(3)H]MK-0974 has proven to be a useful tool for studying the binding characteristics of MK-0974 and has broadened our understanding of this promising molecule.

Current migraine management - patient acceptability and future approaches

Despite its high prevalence and individual as well as societal burden, migraine remains underdiagnosed and undertreated. In recent years, the options for the management of migraine patients have greatly expanded. A number of drugs belonging to various pharmacological classes and deliverable by several routes are now available both for the acute and the preventive treatments of migraine. Nevertheless, disability and satisfaction remain low in many subjects because treatments are not accessible, not optimized, not effective, or simply not tolerated. There is thus still considerable room for better education, for more efficient therapies and for greater support from national health systems. In spite of useful internationally accepted guidelines, anti-migraine treatment has to be individually tailored to each patient taking into account the migraine subtype, the ensuing disability, the patient's previous history and present expectations, and the co-morbid disorders. In this article we will summarize the phenotypic presentations of migraine and review recommendations for acute and preventive treatment, highlighting recent advances which are relevant for clinical practice in terms of both diagnosis and management.

Sickness Absence Among Female Employees With Migraine and Co-Existing Conditions

This prospective cohort study examined the risk of sickness absence among 27 127 female public-sector employees by status of migraine and co-existing conditions. A baseline survey was used to assess chronic disorders and demographic factors. Information on sickness absence in the 3 years following the survey was obtained from employers' registers. Migraine was related to 5.4 extra sickness absence days per person-year, with the corresponding figures being 14.6 and 6.1 for depression and respiratory disorders, respectively. After adjusting for age, marital status, socioeconomic status and presence of depression or respiratory disorders, employees with migraine had a 1.21 (95± confidence interval 1.18, 1.24) times higher risk of self-certified sickness absence episodes (≤ 3 days) than did those without migraine. The corresponding excess risk for medically certified absence episodes (≤ 3 days) was 1.15 (1.12, 1.19). Among employees with depression or respiratory disorders, secondary migraine was associated with an increased risk of sickness absence episode of 1.15 to 1.23. These findings suggest that migraine is associated with increased risk of recorded sickness absence independent of depression and respiratory disorders.

Development and validation of a pharmacy migraine questionnaire to assess suitability for treatment with a triptan

A questionnaire (Migraine Questionnaire; MQ) was developed to help pharmacists identify consumers with migraine suitable for non-prescription treatment with a triptan. Adults, who knew or thought that they had migraine, participated in three, sequential, community-based studies to validate the MQ. Overall, 1,353 subjects completed independent assessments with a pharmacist and a clinician (reference standard). The accuracy of the pharmacist assessment of suitability for a triptan was compared with the clinician assessment. Clinicians using their standard practice determined that triptan therapy was suitable in 76.8% of cases compared with 48.8% for pharmacists using the MQ. The lack of concordance between pharmacists and clinicians in the false-positive cases (n = 113 of 660 subjects considered suitable for triptan by the pharmacists) usually related to headache diagnosis (57.5%), not safety aspects. The MQ is an effective tool for pharmacists to guide appropriate recommendation of a non-prescription triptan for migraine.

Intrapulmonary and intravenous administrations of dihydroergotamine mesylate have similar cardiovascular effects in the conscious dog

BACKGROUND AND PURPOSE

The effects of intrapulmonary artery (i.p.a.) administration of dihydroergotamine mesylate (DHE) were evaluated.

EXPERIMENTAL APPROACH

Conscious beagle dogs (n=4) were given DHE via the i.p.a. or i.v. route as two 0.014 mg kg(-1) doses and a 0.14 mg kg(-1) dose given 60 min apart. A recovery period of > or =45 h occurred before crossover to the alternative route. Physiological parameters were monitored by telemetry or direct measurement, and venous blood samples were collected for pharmacokinetic assessments.

KEY RESULTS

No meaningful differences between i.v. and i.p.a. treatments were observed for heart rate, systemic pressures and vascular pressures. Aortic resistance increased 8, 27 and 70%, respectively, following three doses of i.v. DHE compared with 11, 37 and 57%, respectively, with i.p.a. DHE. Carotid artery resistance increased 22, 40 and 87%, respectively, following three doses of i.v. DHE, compared with 17, 45 and 67%, respectively, following i.p.a. DHE. Increases in coronary artery resistance were of similar magnitude following i.v. and i.p.a. DHE administration. Increases in left ventricular systolic and diastolic pressures were seen following all doses of i.v. and i.p.a. DHE. Changes following DHE 0.014 mg kg(-1) were minimal and not clinically significant. With DHE 0.14 mg kg(-1) by either route, emesis was the most common adverse event.

CONCLUSIONS AND IMPLICATIONS

DHE has comparable effects delivered via simulated deep inhalation (i.p.a.) or i.v. administration. The risk of cardiovascular complications is unlikely to be greater following inhalation of DHE.

Refractory headache: historical perspective, need, and purposes for an operational definition

The study of migraine has yielded many benefits for headache patients. Little research, however, has been performed on refractory migraine (RM) headache, a term often used interchangeably with intractable migraine. This may be a consequence of a lack of a well-accepted definition. In a survey performed by the Refractory Headache Special Interest Section (RHSIS) on the American Headache Society (AHS) in 2006, 58% of the members agreed that a definition for refractory headache should be added to the International Classification of Headache Disorders-2. A PubMed search identified 21 articles that defined refractory or intractable headache/migraine. Sixteen (76%) defined the term "refractory" and 5 (24%) defined the term "intractable." Many of these definitions did not address the need for an adequate trial of a preventive medicine, disability, and medication overuse. An operational definition will allow us to better characterize the disorder, address unmet medical needs, and identify the most effective treatments. RHSIS of the AHS has proposed a definition of RM. It is our hope that this definition will spur interest in this entity and will lead to further research in the area.

Use of 5-HT1 Agonists in Pregnancy

OBJECTIVE:

To report and evaluate available data on the use of serotonin 5-HT1 agonists (triptans) during pregnancy.

DATA SOURCES:

A PubMed search, limited to English-language articles on human subjects, was conducted (1990–December 2007) using the search terms pregnancy, migraine, and the individual triptan drug names. In addition, the manufacturers of all 7 available triptans were contacted regarding the existence of a pregnancy registry for their drug(s) and the availability of registry reports.

STUDY SELECTION AND DATA EXTRACTION:

All retrospective and prospective studies reporting on pregnancy outcomes after the use of a triptan were included and critically evaluated. Data from all available manufacturer-sponsored pregnancy registries were also included.

DATA SYNTHESIS:

Safe and effective treatment of migraine during pregnancy is imperative. Data involving sumatriptan and, to a lesser extent, naratriptan and rizatriptan, exist primarily regarding exposure in the first trimester. These data show no significant differences in congenital malformations or poor pregnancy outcomes when compared with expected rates in the general population or with the observed rates in control subjects. There is very little information regarding exposure in middle and late pregnancy.

CONCLUSIONS:

Sumatriptan appears to be a safe treatment alternative for pregnant women who experience new-onset or worsened migraines in the first trimester. Further observation is needed prior to recommending its use in later trimesters. Based upon available data, the other agents in this class cannot be recommended for use during pregnancy at this time.

Neurovascular pharmacology of migraine

Migraine is a paroxysmal neurovascular disorder, which affects a significant proportion of the population. Since dilation of cranial blood vessels is likely to be responsible for the headache experienced in migraine, many experimental models for the study of migraine have focussed on this feature. The current review discusses a model that is based on the constriction of carotid arteriovenous anastomoses in anaesthetized pigs, which has during the last decades proven of great value in identifying potential antimigraine drugs acting via a vascular mechanism. Further, the use of human isolated blood vessels in migraine research is discussed. Thirdly, we describe an integrated neurovascular model, where dural vasodilatation in response to trigeminal perivascular nerve stimulation can be studied. Such a model not only allows an in-depth characterization of directly vascularly acting drugs, but also of drugs that are supposed to act via inhibition of vasodilator responses to endogenous neuropeptides, or of drugs that inhibit the release of these neuropeptides. We discuss the use of this model in a study on the influence of female sex hormones on migraine. Finally, the implementation of this model in mice is considered. Such a murine model allows the use of genetically modified animals, which will lead to a better understanding of the ion channel mutations that are found in migraine patients.

Emerging therapies for migraine

Migraine is a common disabling brain disorder that--considering its clinical and economic impact--is understudied and in need of additional management options. Currently, treatments are classified as preventive or acute-attack therapies, although it is expected that this distinction will become blurred over time. The gap-junction blocker tonabersat, an inducible nitric oxide synthase (NOS) inhibitor and botulinum toxin A are all being investigated in clinical trials as preventive therapies. Device-based approaches using neurostimulation of the occipital nerve have provided promising results, whereas the first study of patent foramen ovale closure for migraine prevention produced disappointing results. Calcitonin gene-related peptide receptor antagonists, vanilloid TRPV1 receptor antagonists and NOS inhibitors are all being investigated in clinical trials for acute migraine. There is much cause for optimism in this area of neurology and considerable benefit awaits our patients.

Over-the-counter triptans for migraine : what are the implications?

In 2006, the triptans sumatriptan 50mg and naratriptan 2.5mg were approved as over-the-counter (OTC) drugs in pharmacies in the UK and Germany, respectively. Both drugs have been used in a large number of patients with migraine and are considered to have good safety profiles. The implications of OTC triptan availability for clinical practice are that more migraine patients will use a triptan and will tend to medicate early when their headache is still mild, which should be beneficial. The problem with OTC access to triptans is medication overuse; therefore, patients should be warned of this and advised to use a triptan on fewer than 10 days per month. Pharmacists should be educated regarding migraine types and symptoms and on contraindications to triptans, so they are then able to discern the patients who should receive triptans and, as importantly, those who should not. The annual cost of migraine is euro27 billion in Europe, $US1.4 billion in the UK and $US16.6 billion in the US. By far the greatest opportunity for cost-savings comes from the potential to reduce costs associated with lost productivity from migraine. OTC availability of triptans will inevitably result in easier access to these medications, which, in turn, may result in improved treatment and lower migraine-related disability. There is currently a lack of empirical evidence that treating migraine effectively does in fact recover lost productivity; well designed studies are required to show this. The availability of triptans OTC is a logical development for the better management of a common, benign, self-limiting but nonetheless burdensome disorder that is currently grossly undertreated. We welcome this development, but recognise that advice at the point of sale is crucial for effective and safe use of these drugs.

Understanding the causes and prevention of menstrual migraine: the role of estrogen

Menstruation increases the risk of migraine in susceptible women. In a subpopulation of women with menstrual migraine, headaches occurring in association with onset of menses may be more severe and of longer duration than headaches experienced by the same woman at other times of her menstrual cycle. Although menstrual migraines share many clinical characteristics of other types of migraines, their occurrence is predictable provided that the patient has regular menstrual cycles. Therefore, short-term prevention regimens can be considered for women whose headaches are not adequately managed with acute therapies.

Treatment-emergent CNS symptoms following triptan therapy are part of the attack

If treatment-emergent central nervous system (CNS) symptoms following triptan therapy represent direct pharmacological effects of the drug, they should occur independent of response to active drug. However, if they represent unmasking of neurological symptoms of the migraine attack after pain is relieved, they should be more common in responders both to active drug and to placebo. To explore this issue, we evaluated the relationship between the CNS adverse events and treatment response following triptan or placebo treatment. We used pooled data from seven double-blind, placebo-controlled trials involving eletriptan 20 mg (E20, n = 402), eletriptan 40 mg (E40, n = 1870), eletriptan 80 mg (E80, n = 1393), sumatriptan 100 mg (S100, n = 275) and placebo (Pbo, n = 1024). Somnolence was more prevalent among 2 h headache responders than non-responders for all treatments, including E80 (8.8% vs. 5.0%; P < 0.05), E40 (6.4% vs. 5.0%; NS), E20 (4.0% vs. 2.0%; NS), S100 (4.7% vs. 3.2%; NS) and Pbo (7.6% vs. 3.0%; P < 0.05). Similarly, the incidence of asthenia was higher among patients who responded to treatment compared with those who did not respond to E80 (15.2% vs. 7.8%; P < 0.05), E40 (6.5% vs. 3.6%; P < 0.05), E20 (6.5% vs. 1.0%; P < 0.05), S100 (10.1% vs. 4.7%; NS) and Pbo (4.4% vs. 2.7%; NS). The generally higher rates of somnolence and asthenia in patients who respond to treatment suggests that these treatment-emergent neurological symptoms may represent the unmasking of CNS symptoms associated with the natural resolution of a migraine attack, rather than simply representing drug-related side-effects. The rate of somnolence in placebo responders is comparable to that in responders to E40 and E80, indicating that somnolence is related, at least in some important part, to headache relief and not treatment.

Use of the sustained pain-free plus no adverse events endpoint in clinical trials of triptans in acute migraine

OBJECTIVE

To assess the relationship between the sustained pain free (SPF) and adverse event (AE) rates associated with six oral serotonin 5-HT(1B/1D) receptor agonists (triptans) used for the treatment of acute migraine, employing data from a previous meta-analysis (that included almotriptan, eletriptan, naratriptan, rizatriptan, sumatriptan and zolmitriptan, but not frovatriptan) in order to provide a rationale for the use of the rate of patients who are SPF plus no AE (SNAE) as an endpoint in trials of medications for acute migraine.

BACKGROUND

The attributes of drug treatment for acute migraine that are most important to people who experience them are complete pain relief, lack of recurrence, rapid onset and lack of AEs. The endpoints used to assess therapy for acute migraine do not always address these elements.

METHODS

The relationship between SPF and AE rates was explored using nonparametric regression techniques, and the box-plot method was used to identify outliers. The estimated SNAE rate for each triptan was calculated with and without assuming independence between efficacy and tolerability.

RESULTS

At the level of the individual agent, there was a significant relationship between the efficacy and tolerability of each triptan, with the exception of almotriptan 12.5 mg, which had an AE rate approximately 30% lower than would be expected, and eletriptan 20 mg, which had an AE rate approximately 20% higher than would be expected, on the basis of their efficacy. Almotriptan 12.5 mg and eletriptan 20 mg had the highest and lowest base-case values for SNAE, respectively, and both qualified statistically as outliers to the distribution of SNAE values obtained with the other triptans. The probability that each triptan was superior to the reference agent (sumatriptan 100 mg) in terms of SNAE was calculated across all possible values (at the level of the individual patient) for the relationship between efficacy and tolerability. Again, almotriptan 12.5 mg and eletriptan 20 mg had the highest and lowest values for their SNAE rates, respectively, and almotriptan 12.5 mg qualified statistically as an outlier from the distribution of the probabilities obtained for the other triptans.

CONCLUSION

This analysis determined that higher SPF rates were strongly associated with higher AE rates, with the notable exception of almotriptan 12.5 mg, which had a lower than expected AE rate, resulting in the highest SNAE rate of the included triptans and doses. SNAE is a useful measure that can be used to discriminate between therapies and this endpoint incorporates the attributes that are most relevant to patient satisfaction with treatment. We recommend calculation of the SNAE rate at the level of the individual patient in future clinical trials of medication for the treatment of acute migraine to facilitate selection of a treatment for acute migraine that offers the best chance for effective management.

Tailoring management strategies for the patient with menstrual migraine: focus on prevention and treatment

Many women report an increased frequency of headaches around the time of menses. For some women, these headaches are more severe, of longer duration, and lead to greater disability than those occurring at other times in the menstrual cycle. A headache diary is critical to properly diagnose menstrual migraine (MM) by prospectively documenting headache days, severity of headache, and the headaches' relationship to menses. In women with diagnosed MM, acute treatment has been proven to be effective in randomized clinical trials. For those women who have predictable periods and may require preventive therapy, short-term prevention is a reasonable approach due to the predictability of MM. Although several agents (eg, naproxen sodium, magnesium, triptans) have been evaluated for prevention of MM, all but triptans have been assessed in small trials of between 20 and 35 women. Naratriptan, frovatriptan, and, most recently, zolmitriptan have been proven effective in preventing MM. Triptans are generally well tolerated, and the long-term safety of these agents is currently being evaluated. The flexibility of using acute and preventive therapy allows physicians to tailor treatment of MM and meet the needs of individual patients.

A Practical Approach to Headache Treatment

The World Health Organization cites migraine headache as one of the 20 most disabling medical conditions. This article focuses on the diagnosis and treatment of the primary headache disorders, with special emphasis on migraine, the headache most likely to bring patients to physicians and pharmacists. This review begins with the warning signs of the ominous headache, which, although rare, can herald a life-threatening condition. Clinical characteristics of the primary headache types, migraine, tension-type headache, and cluster headache, are described. Although many individuals believe their headaches are “sinus,” or “stress or tension-induced,” most of the characteristics of these types of headaches actually meet International Headache Society criteria for migraine. Treatments of primary headaches, including acute therapies, abortive agents, and prophylactic medications, are uniquely specific for each headache syndrome. Chronic daily headache patients compose only 4% of the population yet make up the largest percentage of patients who seek treatment at specialty headache centers. Medication-overuse headache, the syndrome in which medications taken for the relief of headache actually foster future headaches, offers a particular challenge to health care providers, as does narcotic use in headache therapy. Complementary and alternative treatments proven efficacious in the treatment of primary headache are also described.

Crossover, double-blind clinical trial comparing almotriptan and ergotamine plus caffeine for acute migraine therapy

In this randomized, double-blind, crossover clinical trial, adult patients treated two migraine attacks: one with almotriptan 12.5 mg and the other with ergotamine 2 mg plus caffeine 200 mg. Treatment with almotriptan was associated with a significantly greater proportion of patients achieving 2-h pain free (20.9% vs. 13.7%; P < 0.05) and 2-h pain relief (57.7% vs. 44.5%; P < 0.01) compared with ergotamine plus caffeine therapy; significant differences were not seen at 1 h. Rates for sustained pain free and sustained pain free plus no adverse events (AEs) also were significantly greater after almotriptan treatment than after the use of ergotamine plus caffeine (P < 0.05). Almotriptan was associated with a significantly lower rate of photophobia at 90 min (P < 0.05), phonophobia at 60, 90, and 120 min (P < 0.05 to <0.01), and nausea and vomiting at 90 and 120 min (P < 0.01) compared with ergotamine plus caffeine. A significantly greater proportion of patients were more satisfied with almotriptan than with ergotamine plus caffeine (P < 0.05). Sixteen patients reported adverse events during almotriptan treatment and 27 patients reported AEs during the ergotamine plus caffeine therapy. Most AEs were mild-to-moderate and did not result in treatment-related discontinuations. In conclusion, almotriptan was associated with significantly greater efficacy for treating migraine compared with ergotamine plus caffeine, was generally well tolerated and was associated with greater rate of treatment satisfaction.

Sumatriptan: update and review

Sumatriptan is the first of a novel class of medications referred to as triptans. Since its approval for migraine in the 1990s, six other triptan products have received FDA approval. Despite the proliferation of triptans, sumatriptan remains the most frequently prescribed product in this therapeutic class. Sumatriptan has been instrumental in defining a biological basis for migraine. It is effective in treating migraine with or without aura, well tolerated and, when properly prescribed, safe. Sumatriptan injection is the only member of the triptan class approved for treatment of cluster headache. Studies with sumatriptan have also advanced the therapeutic intervention paradigm that permits patients to treat earlier and avoid substantial disability. Numerous pharmacoeconomic studies have demonstrated that sumatriptan decreases work loss productivity and improves quality of life.

Almotriptan and zolmitriptan in the acute treatment of migraine

OBJECTIVE

To compare almotriptan and zolmitriptan in the treatment of acute migraine.

METHODS

This multicentre, double-blind trial randomized adult migraineurs to almotriptan 12.5 mg (n = 532) or zolmitriptan 2.5 mg (n = 530) for the treatment of a single migraine attack. The primary end point was sustained pain free plus no adverse events (SNAE); other end points included pain relief and pain free at several time points, sustained pain free, headache recurrence, use of rescue medication, functional impairment, time lost because of migraine, treatment acceptability, and overall treatment satisfaction.

RESULTS

No significant difference was seen in SNAE (almotriptan 29.2% vs zolmitriptan 31.8%) or the other efficacy end points measured. The incidence of triptan-associated AEs and triptan-associated central nervous system AEs was significantly lower for patients receiving almotriptan compared to zolmitriptan.

CONCLUSIONS

Almotriptan and zolmitriptan were associated with similar efficacy and overall tolerability in the treatment of acute migraine. Almotriptan was associated with a significantly lower rate of triptan-associated AEs.

Twelve-month tolerability and safety of sumatriptan-naproxen sodium for the treatment of acute migraine

OBJECTIVES

To evaluate the long-term safety and tolerability of sumatriptan-naproxen sodium for the treatment of moderate to severe acute migraines and to assess the safety of administration of an optional second dose.

PATIENTS AND METHODS

A 12-month, multicenter, open-label safety study was conducted in adults treated for migraine attacks of moderate to severe intensity from April 14, 2004, to August 18, 2005. Safety evaluations included adverse events and laboratory tests.

RESULTS

Of 600 patients enrolled, 565 (94%) were treated for at least 1 migraine. Of treated patients, 414 (73%) and 362 (64%) completed 6 and 12 months of treatment, respectively. Of the 24,485 attacks treated, 17,144 (70%) were treated with only 1 dose. On average, patients treated 5 migraine attacks per month, with a median of 6 days between attacks. The most common treatment-related adverse events were nausea, muscle tightness, and dizziness. Fourteen patients reported 1 or more serious adverse event with only 1 judged probably related to treatment. No deaths occurred. Eight percent of patients discontinued participation in the study because of adverse events or pregnancy. The rates of adverse events reported were no higher after treatment with 2 tablets (at least 2 hours apart) compared with 1 tablet.

CONCLUSIONS

In this 12-month data set of more than 24,000 migraine attacks in 565 patients, sumatriptan-naproxen sodium formulated in a single tablet was well tolerated when used episodically for the treatment of acute migraine. The adverse events did not differ from those expected for the individual components alone, and no new or unexpected findings occurred.

Serotonin receptor ligands: treatments of acute migraine and cluster headache

Fuelled by the development of the serotonin 5-HT(1B/1D) receptor agonists, the triptans, the last 15 years has seen an explosion of interest in the treatment of acute migraine and cluster headache. Sumatriptan was the first of these agonists, and it launched a wave of therapeutic advances. These medicines are effective and safe. Triptans were developed as cranial vasoconstrictors to mimic the desirable effects of serotonin, while avoiding its side-effects. It has subsequently been shown that the triptans' major action is neuronal, with both peripheral and central trigeminal inhibitory effects, as well as actions in the thalamus and at central modulatory sites, such as the periaqueductal grey matter. Further refinements may be possible as the 5-HT(1D) and 5-HT(1F) receptor agonists are explored. Serotonin receptor pharmacology has contributed much to the better management of patients with primary headache disorders.

Practical considerations for the treatment of elderly patients with migraine

Treatment of migraine presents special problems in the elderly. Co-morbid diseases may prohibit the use of some medications. Moreover, even when these contraindications do not exist, older patients are more likely than younger ones to develop adverse events. Managing older migraine patients, therefore, necessitates particular caution, including taking into account possible pharmacological interactions associated with the greater use of drugs for concomitant diseases in the elderly. Paracetamol (acetaminophen) is the safest drug for symptomatic treatment of migraine in the elderly. Use of selective serotonin 5-HT(1B/1D) receptor agonists ('triptans') is not recommended, even in the absence of cardiovascular or cerebrovascular risk, and NSAID use should be limited because of potential gastrointestinal adverse effects. Prophylactic treatments include antidepressants, beta-adrenoceptor antagonists, calcium channel antagonists and antiepileptics. Selection of a drug from one of these classes should be dictated by the patient's co-morbidities. Beta-adrenoceptor antagonists are appropriate in patients with hypertension but are contraindicated in those with chronic obstructive pulmonary disease, diabetes mellitus, heart failure and peripheral vascular disease. Use of antidepressants in low doses is, in general, well tolerated by elderly people and as effective, overall, as in young adults. This approach is preferred in patients with concomitant mood disorders. However, prostatism, glaucoma and heart disease make the use of tricyclic antidepressants more difficult. Fewer efficacy data in the elderly are available for selective serotonin reuptake inhibitors, which can be tried in particular cases because of their good tolerability profile. Calcium channel antagonists are contraindicated in patients with hypotension, heart failure, atrioventricular block, Parkinson's disease or depression (flunarizine), and in those taking beta-adrenoceptor antagonists and monoamine oxidase inhibitors (verapamil). Antiepileptic drug use should be limited to migraine with high frequency of attacks and refractoriness to other treatments. Promising additional strategies include ACE inhibitors and angiotensin II type 1 receptor antagonists because of their effectiveness and good tolerability in patients with migraine, particularly in those with hypertension. Because of its favourable compliance and safety profile, botulinum toxin type A can be considered an alternative treatment in elderly migraine patients who have not responded to other currently available migraine prophylactic agents. Pharmacological treatment of migraine poses special problems in regard to both symptomatic and prophylactic treatment. Contraindications to triptan use, adverse effects of NSAIDs, and unwanted reactions to some antiemetics reduce the list of drugs available for the treatment of migraine attacks in elderly patients. The choice of prophylactic treatment (beta-adrenoceptor antagonists, calcium channel antagonists, antiepileptics, and more recently, some antihypertensive drugs) is influenced by co-morbidities and should be directed at those drugs that are believed to have fewer adverse effects and a better safety profile. Unfortunately, for most of these drugs, efficacy studies are lacking in the elderly.

Non-oral formulations of triptans and their use in acute migraine

The introduction of triptans (5-HT (1B/1D) agonists) into clinical practice has expanded the therapeutic options for doctors treating migraine sufferers. The triptans are available in several different formulations such as conventional oral tablets, orally disintegrating wafers, subcutaneous injections, nasal sprays, and suppositories, which provide an excellent opportunity to tailor therapy to individual patients' needs. Although the oral formulations are the most popular with patients, they are not the most appropriate route of administration for drug delivery during the migraine attack. Due to gastrointestinal dysmotility, the intestinal absorption of any triptan administered orally may be impaired and treatment effects become inconsistent. For this reason, triptans preferably should be prescribed in a non-oral formulation (injection, nasal spray, or suppository). Parenteral administration of a triptan is more likely to provide relief of symptoms, even when it is used later in the course of the migraine attack.

New and future migraine therapy

Modern neuroscience advanced our understanding of putative migraine mechanisms, which led to improved therapeutics. Indeed, mechanism-based acute migraine therapy gained steam in the early 1990s after the introduction of the triptans (5-HT1B,D agonists). Post-triptans, novel targets such as calcitonin gene-related peptide (CGRP) antagonists, inhibitors of excitatory glutamatergic receptors, and nitric oxide synthase (NOS) inhibitors are leading the pack in this exploding field of discovery research. In contrast, novel therapeutic targets for migraine prevention are lacking despite a hugely unmet need. To date, migraine prophylactic drugs are advanced based on expanded indications for already approved pharmaceuticals (e.g., topiramate, valproate, propranolol, and timolol). An improved understanding of the predisposition to an attack, genomic discoveries, valid and reliable biomarkers and surrogates, and predictive preclinical models likely will unravel the neuronal substrates for central hyperexcitability and nociceptive dysmodulation, hopefully leading us to better mechanism-based targets for prevention, and ultimately yielding drugs with optimal therapeutic ratios or indices.

Rizatriptan in the treatment of migraine

Migraine is a common, disabling disorder associated with considerable personal and societal burden. Current guidelines recommend triptans for the acute treatment of migraine unlikely to respond to less effective therapies. Rizatriptan is a second-generation triptan available in tablet or orally disintegrating tablet (wafer) formulations that offers several advantages over other members of its class. Rizatriptan is rapidly absorbed from the gastrointestinal tract and achieves maximum plasma concentrations more quickly than other triptans, providing rapid pain relief. Clinical trials have shown that rizatriptan is at least as effective or superior to other oral migraine-specific agents in the acute treatment of migraine, and has more consistent long-term efficacy across multiple migraine attacks. Rizatriptan has a favorable tolerability profile, and patients have reported greater satisfaction and a preference for rizatriptan over other migraine-specific agents. Improvements in quality of life reported with rizatriptan are consistent with its favorable efficacy and tolerability profiles. Notably, multi-attribute decision models that combine clinical data with patient- and physician-reported treatment preferences have identified rizatriptan as one of three triptans closest to a hypothetical "ideal". The efficacy and tolerability of rizatriptan for the acute treatment of migraine have thus been well established.

5-Hydroxytryptamine receptors in the human cardiovascular system

The human cardiovascular system is exposed to plasma 5-hydroxytryptamine (5-HT, serotonin), usually released from platelets. 5-HT can produce harmful acute and chronic effects. The acute cardiac effects of 5-HT consist of tachycardia (preceded on occasion by a brief reflex bradycardia), increased atrial contractility and production of atrial arrhythmias. Acute inotropic, lusitropic and arrhythmic effects of 5-HT on human ventricle become conspicuous after inhibition of phosphodiesterase (PDE) activity. Human cardiostimulation is mediated through 5-HT4 receptors. Atrial and ventricular PDE3 activity exerts a protective role against potentially harmful cardiostimulation. Chronic exposure to high levels of 5-HT (from metastatic carcinoid tumours), the anorectic drug fenfluramine and its metabolites, as well as the ecstasy drug 3,4-methylenedioxymethamphetamine (MDMA) and its metabolite 3,4-methylenedioxyamphetamine (MDA) are associated with proliferative disease and thickening of cardiac valves, mediated through 5-HT2B receptors. 5-HT2B receptors have an obligatory physiological role in murine cardiac embryology but whether this happens in humans requires research. Congenital heart block (CHB) is, on occasion, associated with autoantibodies against 5-HT4 receptors. Acute vascular constriction by 5-HT is usually shared by 5-HT1B and 5-HT2A receptors, except in intracranial arteries which constrict only through 5-HT1B receptors. Both 5-HT1B and 5-HT2A receptors can mediate coronary artery spasm but only 5-HT1B receptors appear involved in coronary spasm of patients treated with triptans or with Prinzmetal angina. 5-HT2A receptors constrict the portal venous system including oesophageal collaterals in cirrhosis. Chronic exposure to 5-HT can contribute to pulmonary hypertension through activation of constrictor 5-HT1B receptors and proliferative 5-HT2B receptors, and possibly through direct intracellular effects.

Migraine: emerging treatment options for preventive and acute attack therapy

This review discusses emerging treatments of migraine in the context of what is now available. At present, patients are treated with a range of acute attack medicines or preventive treatments, with many having significant drawbacks. Important unmet needs are acute attack treatments that act by exclusively neural mechanisms with no vascular effects, and effective, well tolerated preventive medicines. Calcitonin gene-related peptide receptor antagonist, vanilloid receptor antagonists and nitric oxide synthase inhibitors are all in clinical trials for acute migraine. Tonaberset (a gap-junction blocker), an inducible nitric oxide synthase inhibitor and botulinum toxin A are in clinical trials for preventive therapy. Device-based approaches using neurostimulation of the occipital nerve are being studied, although the first study of patent foramen ovale closure for migraine prevention failed.

Optimizing migraine therapy: evidence-based and patient-centered care

Migraine is a chronic, intermittently debilitating neurovascular condition that affects the physical, mental and social aspects of health-related quality of life. Primary care provider interactions with migraine sufferers are common, highlighting the need for clinicians to provide optimal therapy. A comprehensive therapy plan should encompass the whole patient, via a patient-physician partnership where goals and strategies are mutually established. Key treatments include nondrug approaches, such as education and lifestyle modifications, to reduce the occurrence of attacks, as well as acute medications to address the immediate need for relief during an attack. Routine assessment and adjustment of therapy based on data recorded by patient diaries is paramount. Clinical trials support the use of triptans and dihydroergotamine for moderate-to-severe migraine and nonsteroidal anti-inflammatory drugs (alone or in combination with antiemetics or caffeine) for mild-to-moderate migraine, as the treatments of choice to reduce pain and disability time in a cost-effective manner. Published evidence also endorses stratified care, where medication selection is geared towards disease severity, instead of step care, where nonspecific mediations are given to all patients. Thus, patients with significant migraine-induced debilitation, as assessed by tools, such as the Migraine Disability Assessment Scale or the Headache Impact Test, are prescribed migraine-specific agents from the onset of therapy, thereby avoiding the inherent failures of step care. For individuals experiencing a high frequency of attacks or routine debilitation, preventive medications are warranted.

Migraine treatment throughout the lifecycle

The treatment of migraine headache is often suboptimal despite significant advances in our understanding of the pathophysiology and treatment of migraine. Children, adolescents, women and the elderly are particularly at risk of receiving inadequate or inappropriate therapy. In this review, the reader is brought up-to-date with changes to the International Headache Society diagnostic criteria for migraine. The pathophysiology of migraine is also reviewed, with a special emphasis on the evolving concept of central sensitization and cutaneous allodynia since this concept has led to a paradigm shift in the way migraines are managed. A review of the evidence supporting the benefits of early treatment before pain becomes moderate-to-severe is provided. Recommendations for acute and prophylactic treatments throughout the lifecycle are made in light of clinical practice guidelines and more recent evidence. Lastly, the current optimal treatment of migraine is provided and the potential role of calcitonin gene-related peptide antagonists in the future is discussed.

Rizatriptan in migraine

The prevalence of migraine is high, affecting a significant proportion of the adult population during their most productive years of life and promoting impairment of their normal daily activities. Although guidelines for the acute treatment of migraine are available, outcome parameters are sometimes still below the expectations of both patients and physicians. Triptans represented an advance in clinical practice and have become the most well-studied class of medication for migraine. These agents present class I evidence for efficacy. However, they differ with regard to several of their clinical parameters, including onset of relief and consistency of response. Rizatriptan is a selective agonist of the 5-hydroxytryptophan(1B/1D )receptors, with proven superiority over placebo, ergotamine and selected oral triptans, demonstrating a good profile of safety and tolerability.

Eletriptan in migraine

Migraine is a highly prevalent, chronic and disabling illness in which the gap between practice guideline recommendations and actual clinical practice remains wide. Eletriptan, similar to other triptans, is a potent 5-HT(1B/1D) receptor agonist with a high selectivity for cranial versus coronary artery constriction and favorable pharmacokinetic profile. An extensive program of double-blind, placebo-controlled, head-to-head comparator trials has demonstrated the superior efficacy of eletriptan compared with the combination of ergotamine and caffeine, and selected oral triptans for the acute treatment of migraine. Eletriptans tolerability profile makes it a good choice as a first-line treatment of migraine. An early treatment study suggests that treatment of mild headache is associated with unusually high sustained pain-free rates and a tolerability profile that is equivalent to placebo.

[Migraine therapy]

With more than 8 million sufferers in Germany alone, migraine is one of the most frequent medical disorders. Recent discoveries in the pathophysiology and genetics of headaches, as well as specific developments in pharmacology, have paved the way for a significant improvement in both acute migraine treatment and migraine prevention. Within the group of 5-HT(1B/D)-agonists (triptans), seven substances with 23 dosages and formulations have been approved in Germany that allow the customized treatment of migraine attacks. In addition, several new drugs such as valproic acid or topiramate are now available as drugs of first choice for migraine prevention, as well as the well established beta blockers, thus enabling the physician to tailor the preventative treatment according to the individual needs of the patient.

New targets in acute migraine treatment

Migraine is a common and highly disabling neurological problem, whose acute treatment was revolutionized by the triptans, serotonin 5-HT1B/1D receptor agonists. Some patients do not respond to triptans, while others are not suitable for them largely because of contraindications based on vascular disease. The exploration of nonvasoconstrictor treatments for acute migraine offers the prospect of dramatic improvements in patient care, as well as important insights into the mechanisms of migraine. Possibilities for such developments include, calcitonin gene-related peptide receptor antagonists, serotonin 5-HT1F and 5-HT1D receptor agonists, glutamate excitatory amino acid receptor antagonists, nitric oxide synthase inhibitors and adenosine A1 receptor agonists. Taken together, the future for migraine and affected patients is bright and promising.

An otolaryngology, neurology, allergy, and primary care consensus on diagnosis and treatment of sinus headache

While "sinus" headache is a widely accepted clinical diagnosis, many medical specialists consider it to be an uncommon cause of recurrent headaches. Unnecessary diagnostic studies, surgical interventions, and medical treatments are often the result of the inappropriate diagnosis of sinus headache. Both the International Headache Society and the American Academy of Otolaryngology-Head and Neck Surgery have attempted to characterize conditions leading to headaches of rhinogenic origin. However, they have done so from different perspectives and in isolation from the other specialty groups. An interdisciplinary ad hoc committee recently convened to discuss the role of sinus disease and the nose in the etiology of headache and to review recent epidemiologic studies suggesting that sinus headache (headache of rhinogenic origin) and migraine are frequently confused with one another. Clinical trial data are presented which clearly indicate that the majority of sinus headaches can actually be classified as migraines. This committee reviewed scientific evidence available from multiple disciplines and concludes that considerable research and clinical study are needed to further understand and explain the role of nasal pathology and autonomic activation in migraine and headaches of rhinogenic origin. However, there was a consensus from this group that greater diagnostic and therapeutic attention needs to be given to patients complaining of sinus headache that may indeed be due to the nose.

The nonpeptide calcitonin gene-related peptide receptor antagonist BIBN4096BS lowers the activity of neurons with meningeal input in the rat spinal trigeminal nucleus

Calcitonin gene-related peptide (CGRP) has been suggested to play a major role in the pathogenesis of migraines and other primary headaches. CGRP may be involved in the control of neuronal activity in the spinal trigeminal nucleus (STN), which integrates nociceptive afferent inputs from trigeminal tissues, including intracranial afferents. The activity of STN neurons is thought to reflect the activity of central trigeminal nociceptive pathways causing facial pain and headaches in humans. In a rat model of meningeal nociception, single neuronal activity in the STN was recorded. All units had receptive fields located in the exposed parietal dura mater. Heat and cold stimuli were repetitively applied to the dura in a fixed pattern of ramps and steps. The nonpeptide CGRP receptor antagonist BIBN4096BS was topically applied onto the exposed dura or infused intravenously. BIBN4096BS (300 microg/kg, i.v.) reduced spontaneous activity by approximately 30%, the additional dose of 900 microg/kg intravenously by approximately 50% of the initial activity, whereas saline had no effect. The activity evoked by heat ramps was also reduced after BIBN4096BS (900 microg/kg, i.v.) by approximately 50%. Topical administration of BIBN4096BS (1 mm) did not significantly change the spontaneous neuronal activity within 15 min. We conclude that the endogenous release of CGRP significantly contributes to the maintenance of spontaneous activity in STN neurons. Blockade of CGRP receptors, possibly at central and peripheral sites, may therefore be an effective way to decrease nociceptive transmission. This may offer a new therapeutic strategy for the treatment of facial pain and primary headaches.

Can we Develop Neurally Acting Drugs for the Treatment of Migraine?

Serotonin (5-HT)(1B/1D) receptor agonists, which are also known as triptans, represent the most important advance in migraine therapeutics in the four millennia that the condition has been recognized. The vasoconstrictive activity of triptans produced a small clinical penalty in terms of coronary vasoconstriction but also raised an enormous intellectual question: to what extent is migraine a vascular problem? Functional neuroimaging and neurophysiological studies have consistently developed the theme of migraine as a brain disorder and, therefore, demanded that the search for neurally acting antimigraine drugs should be undertaken. The prospect of non-vasoconstrictor acute migraine therapies, potential targets for which are discussed here, offers a real opportunity to patients and provides a therapeutic rationale that places migraine firmly in the brain as a neurological problem, where it undoubtedly belongs.

Sinus headache: a neurology, otolaryngology, allergy, and primary care consensus on diagnosis and treatment

Sinus headache is a widely accepted clinical diagnosis, although many medical specialists consider it an uncommon cause of recurrent headaches. The inappropriate diagnosis of sinus headache can lead to unnecessary diagnostic studies, surgical interventions, and medical treatments. Both the International Headache Society and the American Academy of Otolaryngology-Head and Neck Surgery have attempted to define conditions that lead to headaches of rhinogenic origin but have done so from different perspectives and in isolation of each other. An interdisciplinary ad hoc committee convened to discuss the role of sinus disease as a cause of headache and to review recent epidemiological studies that suggest sinus headache (headache of rhinogenic origin) and migraine are frequently confused with one another. This committee reviewed available scientific evidence from multiple disciplines and concluded that considerable research and clinical study are required to further understand and delineate the role of nasal pathology and autonomic activation in migraine and headaches of rhinogenic origin. However, this group agreed that greater diagnostic and therapeutic attention needs to be given to patients with sinus headaches.

New targets in the acute treatment of headache

PURPOSE OF REVIEW

The aim of this article is to review recently identified targets for the acute treatment of primary headache disorders.

RECENT FINDINGS

Calcitonin gene-related peptide (CGRP) receptor blockade has been shown to be an effective acute anti-migraine strategy and is a non-vasoconstrictor in terms of the mechanism of action. It is likely that direct blockade of CGRP release by inhibition of trigeminal nerves would be similarly effective in both migraine and cluster headache. Options for acute treatment based on preclinical work and initial clinical studies include: serotonin 5HT1F and 5HT1D receptor agonists, glutamate excitatory amino acid receptor antagonists, nitric oxide synthase inhibitors and adenosine A1 receptor agonists. Proof of principle studies with octreotide, a somatostatin receptor agonist, demonstrated it to be better than placebo in the acute treatment of cluster headache but not in the acute management of migraine.

SUMMARY

The prospect of a non-vasoconstrictor acute migraine therapy offers a real opportunity to patients, and perhaps more importantly, provides a therapeutic rationale to plant migraine and cluster headache firmly in the brain as neurological problems.