Coronary vasoconstrictor potential of triptans: a review of in vitro pharmacologic data

Triptan use in elderly over 65 years and the risk of hospitalization for serious vascular events

BACKGROUND

Several studies have focused on the use of triptan and the risk of acute vascular events but the existence of such association is still debated and has never been quantified in patients over 65 years. To assess whether triptan use among older is associated with an increased risk of hospitalization for acute vascular events.

METHODS

A propensity score-matched cohort study was designed using the French national health insurance database linked to hospital stays. Patients aged ≥ 65 years, newly treated by triptans between 2011 and 2014, were included… The primary event was hospitalization for an acute ischemic vascular event within de 90 days following triptan initiation. Association with triptan exposure was investigated through cox regression model, considering exposure at inclusion, and with exposure as a time-varying variable A case-crossover (CCO) and a self-controlled case series (SCCS) analyses were also conducted to address potential residual confounding.

RESULTS

The cohort included 24, 774 triptan users and 99 096 propensity matched controls (mean (SD) age: 71 years (5.9), 74% of women). Within 90 days after cohort entry, 163 events were observed in the triptan group, and 523 in the control group (0.66% vs. 0.53%, adjusted hazard ratio (aHR) exposed/not exposed 1.25 95%CI [1.05-1.49]; aHR time-varying 8.74 [5.21-14.66]). The association was significant (CCO) for all events (adjusted odds ratio (aOR1.63 [1.22-2.19]) with a more consistent association with cerebral events (aOR 2.14 [1.26-3.63]). The relative incidence (RI) for all events was 2.13 [1.76-2.58] in the SCCS, for cardiac (RI: 1.67 [1.23-2.27]) and for cerebral events (RI: 3.20, [2.30-4.45]).

CONCLUSION

The incidence of acute vascular events was low among triptan users. We found that triptan use among older may be associated with a low increased risk for acute vascular events, which may be more marked for cerebral events such as stroke, than for cardiac events.

Health equity, care access and quality in headache - part 2

BACKGROUND

Headache disorders are a global public health concern affecting diverse populations. This review examines headache service organizations in low-, middle-, and high-income countries. It addresses global challenges in pharmacological headache treatment, with a focus on safety, tolerability, reproductive and child health, and outlines disparities in accessing innovative treatments worldwide.

MAIN BODY

Organized headache services are essential due to the wide prevalence and varying severity of headache disorders. The tiered headache service model is globally recognized, although its implementation varies based on financial and workforce considerations. Headache burden affects well-being, causing disability, economic challenges, and work limitations, irrespective of location or income. All nations still require improved diagnosis and treatment, and the majority of countries face obstacles including limited access, awareness, economic barriers, and inadequate health policies. Provided adequate internet availability, telemedicine could help improve health equity by expanding access to headache care, since it can offer patients access to services without lengthy waiting times or extensive travel and can provide healthcare unavailable in underserved areas due to staff shortages. Numerous health disparities restrict global access to many headache medications, especially impacting individuals historically excluded from randomized controlled trials, such as those with cardiovascular and cerebrovascular conditions, as well as pregnant women. Furthermore, despite advancements in researching migraine treatments for young patients, the options for treatment remain limited. Access to headache treatment relies on factors like medication availability, approval, financial coverage, and healthcare provider expertise. Inadequate public awareness leads to neglect by policymakers and undertreatment by patients and healthcare providers. Global access discrepancies are exacerbated by the introduction of novel disease-specific medications, particularly impacting Asian, African, and Latin American nations excluded from clinical trials. While North America and Europe experience broad availability of migraine treatments, the majority of countries worldwide lack access to these therapies.

CONCLUSIONS

Healthcare disparities, treatment access, and medication availability are concerning issues in headache medicine. Variations in national healthcare systems impact headache management, and costly innovative drugs are widening these gaps. Healthcare practitioners and experts should acknowledge these challenges and work towards minimizing access barriers for equitable global headache care in the future.

Duality in response of intracranial vessels to nitroglycerin revealed in rats by imaging photoplethysmography

Among numerous approaches to the study of migraine, the nitroglycerin (NTG) model occupies a prominent place, but there is relatively insufficient information about how NTG affects intracranial vessels. In this study we aim to assess the effects of NTG on blood-flow parameters in meningeal vessels measured by imaging photoplethysmography (iPPG) in animal experiments. An amplitude of the pulsatile component (APC) of iPPG waveform was assessed before and within 2.5 h after the NTG administration in saline (n = 13) or sumatriptan (n = 12) pretreatment anesthetized rats in conditions of a closed cranial window. In animals of both groups, NTG caused a steady decrease in blood pressure. In 7 rats of the saline group, NTG resulted in progressive increase in APC, whereas decrease in APC was observed in other 6 rats. In all animals in the sumatriptan group, NTG administration was accompanied exclusively by an increase in APC. Diametrically opposite changes in APC due to NTG indicate a dual effect of this drug on meningeal vasomotor activity. Sumatriptan acts as a synergist of the NTG vasodilating action. The results we obtained contribute to understanding the interaction of vasoactive drugs in the study of the headache pathophysiology and methods of its therapy.

Association Between Migraine and Ischemic Cardio-Cerebrovascular Disease (CCVD) and Effects of Triptans and Ergotamine on the Risk of Ischemic CCVD in Patients with Migraine in the Korean NHIS-HEALS Cohort

BACKGROUND AND OBJECTIVES

Triptans and ergotamine are commonly used to treat migraine, a risk factor for ischemic stroke. This study aimed to investigate the association between migraine and ischemic cardio-cerebrovascular disease (CCVD). Further analyses were performed to examine whether symptom-relieving treatment of migraine with triptans and ergotamine reduces ischemic CCVD in migraineurs.

METHODS

Participants from the Korean NHIS-HEALS cohort database were divided into patients reporting headache without migraine (HA), migraineurs who received at least one prescription for triptans or ergotamine (TE), and migraineurs who were prescribed neither triptans nor ergotamine (NTNE). Ischemic CCVDs comprised ischemic cerebrovascular diseases and cardiovascular diseases. Using cox proportional hazards regression models, primary and secondary analysis for risk of ischemic CCVDs was compared.

RESULTS

Among 62,272 patients diagnosed with migraine or HA, men with migraine or HA numbered 14,747 and 8935, respectively, while the numbers of women were 27,836 and 10,754, respectively. The median follow-up was 6.65 years. The overall incidence rate of CCVDs was 4728/38,590 (12.25%) in females and 3158/23,682 (13.33%) in males. Compared with the HA group, the hazard ratios (HRs) (95% CIs) of the TE and NTNE groups for ischemic CCVDs were 1.18 (1.01-1.39) and 1.39 (1.28-1.50), respectively, in males, and 1.22 (1.09-1.37) and 1.53 (1.42-1.65), respectively, in females, after full adjustment for confounding variables. Compared with the NTNE group, the HRs (95% CIs) of the TE group for ischemic CCVDs were 0.86 (0.73-0.999) in males and 0.80 (0.72-0.88) in females.

CONCLUSIONS

Migraine increased the risk of ischemic CCVDs in both sexes, and migraineurs treated with triptans and ergotamine were at lower risk of ischemic CCVDs than migraineurs who did not take those medications, especially in women.

European Headache Federation (EHF) consensus on the definition of effective treatment of a migraine attack and of triptan failure

Background

Triptans are migraine-specific acute treatments. A well-accepted definition of triptan failure is needed in clinical practice and for research. The primary aim of the present Consensus was to provide a definition of triptan failure. To develop this definition, we deemed necessary to develop as first a consensus definition of effective treatment of an acute migraine attack and of triptan-responder.

Main body

The Consensus process included a preliminary literature review, a Delphi round and a subsequent open discussion. According to the Consensus Panel, effective treatment of a migraine attack is to be defined on patient well-being featured by a) improvement of headache, b) relief of non-pain symptoms and c) absence of adverse events. An attack is considered effectively treated if patient’s well-being, as defined above, is restored within 2 hours and for at least 24 hours. An individual with migraine is considered as triptan-responder when the given triptan leads to effective acute attack treatment in at least three out of four migraine attacks. On the other hand, an individual with migraine is considered triptan non-responder in the presence of failure of a single triptan (not matching the definition of triptan-responder). The Consensus Panel defined an individual with migraine as triptan-resistant in the presence of failure of at least 2 triptans; triptan refractory, in the presence of failure to at least 3 triptans, including subcutaneous formulation; triptan ineligibile in the presence of an acknowledged contraindication to triptan use, as specified in the summary of product characteristics.

Conclusions

The novel definitions can be useful in clinical practice for the assessment of acute attack treatments patients with migraine. They may be helpful in identifying people not responding to triptans and in need for novel acute migraine treatments. The definitions will also be of help in standardizing research on migraine acute care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01502-z.

Cardiovascular Disease and Migraine: Are the New Treatments Safe?

PURPOSE OF REVIEW

The authors present data on cardiovascular safety for the new acute and preventive migraine treatments including ditans, gepants, and calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) alongside older medications like triptans and ergotamines.

RECENT FINDINGS

The authors conclude that there are no cardiovascular safety concerns for lasmiditan, and that it could be used in those with cardiovascular disease. In fact, the literature even suggests that triptans are safer in cardiovascular disease than their contraindications may suggest. At this time, there is insufficient evidence that gepants and CGRP mAbs should be contraindicated in those with cardiovascular disease including stroke or myocardial infarction, though erenumab has now been associated with hypertension. Vasodilation may be an important CGRP-mediated mechanism mid-ischemia especially in patients with small vessel disease; hence, CGRP antagonists should be use with caution in this context. Long-term data is still needed, and prescribers should ensure patients are aware of the limitations of our knowledge at this time, while still offering these effective and well-tolerated treatment options.

Drug Safety in Episodic Migraine Management in Adults Part 1: Acute Treatments

PURPOSE OF REVIEW

The aim of this review is to aid in choosing safe options when assessing potential risks of acute migraine treatments based on known mechanisms of action and anticipated safety concerns.

RECENT FINDINGS

Part 1 highlights safety issues associated with commonly used medications to treat acute migraine attacks. Strategies to mitigate cardiovascular and gastrointestinal risks of nonsteroidal anti-inflammatory drugs, evaluation of cardiovascular risks of triptan and ergot alkaloids, and precautions with use of antiemetics and the novel drugs gepants and ditans are discussed to help practitioners in clinical decision-making. When available, we included recommendations from professional societies and data from pharmacovigilance systems. While guidelines on efficacy are available, one must also consider the possible risks and adverse effects of a drug when creating treatment plans.

Drug interactions and risks associated with the use of triptans, ditans and monoclonal antibodies in migraine

PURPOSE OF REVIEW

The aim of this study was to review current evidence concerning potential risks and interactions associated with concomitant use of drugs indicated for the abortive treatment of migraine, namely triptans and ditans, and more recently developed drugs used for the preventive treatment. The latter drug class encompasses monoclonal antibodies (mAbs), which target either calcitonin gene-related peptide (CGRP) or its receptor.

RECENT FINDINGS

To date, no pharmacokinetic interactions between these drug classes have been reported. However, patients who suffer from triptan- (or ditan-) induced medication overuse headache or those who are nonresponders to triptans might respond less effectively to mAbs. Caution is warranted when coadministrating these drugs in migraine patients with comorbid cardiovascular disease or with an increased cardiovascular risk profile.

SUMMARY

In this review, the main mechanisms of action of triptans, ditans and mAbs targeting CGRP or its receptor are summarized as well as the current evidence on their individual risks. Studies on risks and interactions in case of concomitant use of triptans, ditans and mAbs in migraine patients are relatively scarce. Therefore, these aspects have been considered from a theoretical and hypothetical point of view by taking both their overlapping target, CGRP, and contraindications into account.

Pharmacological treatment of migraine: CGRP and 5-HT beyond the triptans

Migraine is a highly disabling neurovascular disorder characterized by a severe headache (associated with nausea, photophobia and/or phonophobia), and trigeminovascular system activation involving the release of calcitonin-gene related peptide (CGRP). Novel anti-migraine drugs target CGRP signaling through either stimulation of 5-HT1F receptors on trigeminovascular nerves (resulting in inhibition of CGRP release) or direct blockade of CGRP or its receptor. Lasmiditan is a highly selective 5-HT1F receptor agonist and, unlike the triptans, is devoid of vasoconstrictive properties, allowing its use in patients with cardiovascular risk. Since lasmiditan can actively penetrate the blood-brain barrier, central therapeutic as well as side effects mediated by 5-HT1F receptor activation should be further investigated. Other novel anti-migraine drugs target CGRP signaling directly. This neuropeptide can be targeted by the monoclonal antibodies eptinezumab, fremanezumab and galcanezumab, or by CGRP-neutralizing L-aptamers called Spiegelmers. The CGRP receptor can be targeted by the monoclonal antibody erenumab, or by small-molecule antagonists called gepants. Currently, rimegepant and ubrogepant have been developed for acute migraine treatment, while atogepant is studied for migraine prophylaxis. Of these drugs targeting CGRP signaling directly, eptinezumab, erenumab, fremanezumab, galcanezumab, rimegepant and ubrogepant have been approved for clinical use, while atogepant is in the last stage before approval. Although all of these drugs seem highly promising for migraine treatment, their safety should be investigated in the long-term. Moreover, the exact mechanism(s) of action of these drugs need to be elucidated further, to increase both safety and efficacy and to increase the number of responders to the different treatments, so that all migraine patients can satisfactorily be treated.

A global real-world assessment of the impact on health-related quality of life and work productivity of migraine in patients with insufficient versus good response to triptan medication

Background

Migraine is a chronic, disabling neurological disease characterized by moderate-to-severe headache pain with other symptoms, including nausea, vomiting, and photophobia. Triptans, while generally effective, are insufficiently efficacious in 30–40% of patients and poorly tolerated by or contraindicated in others. We assessed the impact of insufficient response to triptans on health-related quality of life (HRQoL) and work productivity in patients currently receiving any prescribed triptan formulation as their only acute migraine medication.

Methods

Data were from the 2017 Adelphi Migraine Disease Specific Programme, a cross-sectional survey of primary care physicians, neurologists, and headache specialists and their consulting patients with migraine in the USA, France, Germany, Italy, Spain, and UK. Triptan insufficient responders (TIRs) achieved freedom from headache pain within 2 h of acute treatment in ≤3/5 migraine attacks; triptan responders (TRs) achieved pain freedom within 2 h in ≥4/5 attacks. Multivariable general linear model examined differences between TIRs and TRs in HRQoL and work productivity. Logistic regression identified factors associated with insufficient response to triptans.

Results

The study included 1413 triptan-treated patients (TIRs: n = 483, 34.2%; TRs: n = 930, 65.8%). TIRs were more likely to be female (76% vs. 70% for TIRs vs TRs, respectively; p = 0.011), older (mean age 42.6 vs. 40.5 years; p = 0.003), and had more headache days/month (7.0 vs. 4.4; p < 0.001). TIRs had significantly more disability, with higher Migraine Disability Scores (MIDAS; 13.2 vs. 7.7; p < 0.001), lower Migraine-specific Quality of Life scores, indicating greater impact (Role Function Restrictive: 62.4 vs. 74.5; Role Function Preventive: 70.0 vs. 82.2; Emotional Function: 67.7 vs. 82.1; all p < 0.001), and lower EQ5D utility scores (0.84 vs. 0.91; p = 0.001). Work productivity and activity were impaired (absenteeism, 8.6% vs. 5.1% for TIRs vs. TRs; presenteeism, 34.3% vs. 21.0%; work impairment, 37.1% vs. 23.3%; overall activity impairment, 39.8% vs. 25.3%; all p < 0.05).

Conclusion

HRQoL and work productivity were significantly impacted in TIRs versus TRs in this real-world analysis of patients with migraine acutely treated with triptans, highlighting the need for more effective treatments for patients with an insufficient triptan response. Further research is needed to establish causal relationships between insufficient response and these outcomes.

The need for new acutely acting antimigraine drugs: moving safely outside acute medication overuse

Background

The treatment of migraine is impeded by several difficulties, among which insufficient headache relief, side effects, and risk for developing medication overuse headache (MOH). Thus, new acutely acting antimigraine drugs are currently being developed, among which the small molecule CGRP receptor antagonists, gepants, and the 5-HT_1F receptor agonist lasmiditan. Whether treatment with these drugs carries the same risk for developing MOH is currently unknown.

Main body

Pathophysiological studies on MOH in animal models have suggested that decreased 5-hydroxytryptamine (5-HT, serotonin) levels, increased calcitonin-gene related peptide (CGRP) expression and changes in 5-HT receptor expression (lower 5-HT_1B/D and higher 5-HT_2A expression) may be involved in MOH. The decreased 5-HT may increase cortical spreading depression frequency and induce central sensitization in the cerebral cortex and caudal nucleus of the trigeminal tract. Additionally, low concentrations of 5-HT, a feature often observed in MOH patients, could increase CGRP expression. This provides a possible link between the pathways of 5-HT and CGRP, targets of lasmiditan and gepants, respectively. Since lasmiditan is a 5-HT_1F receptor agonist and gepants are CGRP receptor antagonists, they could have different risks for developing MOH because of the different (over) compensation mechanisms following prolonged agonist versus antagonist treatment.

Conclusion

The acute treatment of migraine will certainly improve with the advent of two novel classes of drugs, i.e., the 5-HT_1F receptor agonists (lasmiditan) and the small molecule CGRP receptor antagonists (gepants). Data on the effects of 5-HT_1F receptor agonism in relation to MOH, as well as the effects of chronic CGRP receptor blockade, are awaited with interest.

Is selective 5-HT1F receptor agonism an entity apart from that of the triptans in antimigraine therapy?

Migraine is a neurovascular disorder that involves activation of the trigeminovascular system and cranial vasodilation mediated by release of calcitonin gene-related peptide (CGRP). The gold standard for acute migraine treatment are the triptans, 5-HT1B/1D/(1F) receptor agonists. Their actions are thought to be mediated through activation of: (i) 5-HT1B receptors in cranial blood vessels with subsequent cranial vasoconstriction; (ii) prejunctional 5-HT1D receptors on trigeminal fibers that inhibit trigeminal CGRP release; and (iii) 5-HT1B/1D/1F receptors in central nervous system involved in (anti)nociceptive modulation. Unfortunately, coronary arteries also express 5-HT1B receptors whose activation would produce coronary vasoconstriction; hence, triptans are contraindicated in patients with cardiovascular disease. In addition, since migraineurs have an increased cardiovascular risk, it is important to develop antimigraine drugs devoid of vascular (side) effects. Ditans, here defined as selective 5-HT1F receptor agonists, were developed on the basis that most of the triptans activate trigeminal 5-HT1F receptors, which may explain part of the triptans' antimigraine action. Amongst the ditans, lasmiditan: (i) fails to constrict human coronary arteries; and (ii) is effective for the acute treatment of migraine in preliminary Phase III clinical trials. Admittedly, the exact site of action is still unknown, but lasmiditan possess a high lipophilicity, which suggests a direct action on the central descending antinociceptive pathways. Furthermore, since 5-HT1F receptors are located on trigeminal fibers, they could modulate CGRP release. This review will be particularly focussed on the similarities and differences between the triptans and the ditans, their proposed sites of action, side effects and their cardiovascular risk profile.

Phase 1, randomized, parallel-group, double-blind, placebo-controlled trial to evaluate the effects of erenumab (AMG 334) and concomitant sumatriptan on blood pressure in healthy volunteers

OBJECTIVES

The aim of this study was to assess the effects of concomitant administration of erenumab and sumatriptan on resting blood pressure, pharmacokinetics, safety, and tolerability in healthy subjects.

METHODS

In this phase 1, parallel-group, one-way crossover, double-blind, placebo-controlled study, healthy adult subjects were randomized (1:2) to receive either intravenous placebo and subcutaneous sumatriptan 12 mg (i.e. two 6-mg injections separated by 1 hour) or intravenous erenumab 140 mg and subcutaneous sumatriptan 12 mg. Blood pressure was measured pre-dose and at prespecified times post-dose. The primary endpoint was individual time-weighted averages of mean arterial pressure, measured from 0 hours to 2.5 hours after the first dose of sumatriptan. Pharmacokinetic parameters for sumatriptan were evaluated by calculating geometric mean ratios (erenumab and sumatriptan/placebo and sumatriptan). Adverse events and anti-erenumab antibodies were also evaluated.

RESULTS

A total of 34 subjects were randomized and included in the analysis. Least squares mean (standard error) time-weighted averages of mean arterial pressure were 87.4 (1.0) mmHg for the placebo and sumatriptan group and 87.4 (1.2) mmHg for the erenumab and sumatriptan group. Mean difference in mean arterial pressure between groups was -0.04 mmHg (90% confidence interval: -2.2, 2.1). Geometric mean ratio estimates for maximum plasma concentration of sumatriptan was 0.95 (90% confidence interval: 0.82, 1.09), area under the plasma concentration-time curve (AUC) from time 0 to 6 hours was 0.98 (90% confidence interval: 0.93, 1.03), and AUC from time 0 to infinity was 1.00 (90% confidence interval: 0.96, 1.05). No clinically relevant safety findings for co-administration of sumatriptan and erenumab were identified.

CONCLUSION

Co-administration of erenumab and sumatriptan had no additional effect on resting blood pressure or on pharmacokinetics of sumatriptan. Trial registration: ClinicalTrials.gov, NCT02741310.

Migraine and cardiocerebrovascular risk in women

The interest of the medical community has recently focused on the relationship between gender and cardiocerebrovascular risk. In this paper, we will first review gender differences in cardiocerebrovascular disorders, then we will discuss the existing evidence on the links between migraine and stroke and cardiovascular disease in women, and speculate on the possible physiopathological interpretations of this emerging epidemiological link. In the third part of this work, we will address the issue of the effect of sex hormones on vascular risk, and consider the evidence concerning the safety of oral contraceptives and hormone-replacement therapy. Finally, we will outline the main trends of future research and its possible clinical and therapeutic implications.

One hundred years of migraine research: major clinical and scientific observations from 1910 to 2010

Pain research, and headache research in particular, during the 20th century, has generated an enormous volume of literature promulgating theories, questions, and temporary answers. This narrative review describes the most important events in the history of migraine research between 1910 and 2010. Based on the standard textbooks of headache: Wolff's Headache (1948 and 1963) and The Headaches (1993, 2000, and 2006) topics were selected for a historical review. Most notably these included: isolation and clinical introduction of ergotamine (1918); further establishment of vasodilation in migraine and the constrictive action of ergotamine (1938); identification of pain-sensitive structures in the head (1941); Lashley's description of spreading scotoma (1941); cortical spreading depression (CSD) of Leão (1944); serotonin and the introduction of methysergide (1959); spreading oligemia in migraine with aura (1981); oligemia in the wake of CSD in rats (1982); neurogenic inflammation theory of migraine (1987); a new headache classification (1988); the discovery of sumatriptan (1988); migraine and calcitonin gene-related peptide (1990); the brainstem "migraine generator" and PET studies (1995); migraine as a channelopathy, including research from the genetic perspective (1996); and finally, meningeal sensitization, central sensitization, and allodynia (1996). Pathophysiological ideas have evolved within a limited number of paradigms, notably the vascular, neurogenic, neurotransmitter, and genetic/molecular biological paradigm. The application of various new technologies played an important role within these paradigms, in particular neurosurgical techniques, EEG, methods to measure cerebral blood flow, PET imaging, clinical epidemiological, genetic, and molecular biological methods, the latter putting migraine (at least hemiplegic migraine) within a completely new classification of diseases.

Safety and tolerability of frovatriptan in the acute treatment of migraine and prevention of menstrual migraine: Results of a new analysis of data from five previously published studies

BACKGROUND

Triptans are a recommended first-line treatment for moderate to severe migraine.

OBJECTIVE

Using clinical trial data, we evaluated the safety and tolerability of frovatriptan as acute treatment (AT) and as short-term preventive (STP) therapy for menstrual migraine (MM).

METHODS

Data from 2 Phase III AT trials (AT1: randomized, placebo controlled, 1 attack; AT2: 12-months, noncomparative, open label) and 3 Phase IIIb STP trials in MM (MMP1 and MMP2: randomized, placebo controlled, double blind, 3 perimenstrual periods; MMP3: open label, noncomparative, 12 perimenstrual periods) were analyzed. In AT1, patients treated each attack with frovatriptan 2.5 mg, sumatriptan 100 mg, or placebo. In AT2, they used frovatriptan 2.5 mg. In MMP1 and MMP2, women administered frovatriptan 2.5 mg for 6 days during the perimenstrual period, taking a loading dose of 2 or 4 tablets on day 1, followed by once-daily or BID frovatriptan 2.5 mg, respectively; in MMP3, they used BID frovatriptan 2.5 mg. In AT1, which was previously published in part, group differences in adverse events (AEs) were analyzed using the Fisher exact test, and response rates were compared using logistic regression. Post hoc analyses of sustained pain-free status with no AEs (SNAE) and sustained pain response with no AEs (SPRNAE) were performed using a 2-sample test for equality of proportions without continuity correction. For AT2 and the STP studies, data were summarized using descriptive statistics. Results of individual safety analyses for the STP studies were previously reported; the present report includes new results from a pooled analysis of MMP1 and MMP2 and a new analysis of MMP3 in which AEs were coded using Medical Dictionary for Regulatory Activities version 8.0.

RESULTS

AT1 included 1206 patients in the safety group; AT2 included 496. In the STP studies, safety data were collected for 1487 women. In AT1 and AT2, 85.6% and 88.3%, respectively, of enrolled patients were women. Overall, AEs were generally mild to moderate (AT studies: 82.3%-90.0%; STP studies: 78.9%89.5%). In AT1, 27.3% (131/480) of frovatriptan patients, 33.4% (161/482) of sumatriptan patients, and 14.8% (36/244) of placebo patients experienced an AE considered possibly or probably related to treatment (P < 0.001 for either drug vs placebo).There were no significant differences between frovatriptan and sumatriptan in SNAE at 4 to 24 hours or in SPRNAE at 2 to 24 hours or at 4 to 24 hours. In randomized, controlled STP trials for MM, AEs were reported by 57.8% (166/287, BID) and 63.4% (210/331, once daily) of frovatriptan users versus 62.8% (216/344) of placebo recipients. There were no consistent differences in AEs reported by patients with potential cardiovascular risk or in AEs related to the use of estrogencontaining contraceptives (ECCs).

CONCLUSIONS

In randomized controlled trials and 12-month open-label studies, frovatriptan was well tolerated in these women during AT and STP therapy for MM. Subgroup analyses provide preliminary evidence of tolerability in women using ECCs and in women with comorbidities that do not contraindicate triptan use but may be suggestive of cardiovascular risk.

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.

Associations between migraine and cardiovascular disease

Migraine is a common chronic, intermittent headache disorder that in some patients is accompanied by neurological symptoms, particularly visual symptoms, known as migraine aura. Several population-based studies have linked migraine, and particularly migraine with aura, with increased risk of ischemic stroke. Recent prospective data suggest an association between migraine with aura and any ischemic vascular events, including coronary heart disease. The precise biological mechanism by which migraine with aura may increase the risk of vascular events is currently unknown and likely complex. Potential mechanisms involve shared risk factors, inter-relationships between migraine and vascular pathologies, migraine treatments, as well as genetic components. This review aims to summarize the epidemiologic evidence linking migraine with ischemic vascular events, discuss potential mechanisms and to outline potential consequences.

Characterization of the human basilar artery contractile response to 5-HT and triptans

To study the contractile responses of the human basilar artery to 5-hydroxytryptamine (5-HT), sumatriptan, zolmitriptan and naratriptan, and to characterize the 5-HT receptor subtypes involved on those responses, human basilar artery rings were prepared for isometric contraction, protein isolation and Western blotting analysis. Concentration-response (CR) curves were made for all agonists in the absence or in the presence of selective antagonists at 5-HT1B (cyanopindolol), 5-HT1D (BRL 15,572) and 5-HT2 (ketanserin) receptors. We also used anti-5-HT1B and 5-HT1D receptor antibodies to search for the expression of protein of these receptor subtypes. From the CR curves, the relative intrinsic activity and potency of these agonists were determined. The ranking order for the intrinsic activity was 5-HT > or = sumatriptan > zolmitriptan > or = naratriptan, whereas that for the potency was zolmitriptan > or = 5-HT > or = sumatriptan > naratriptan. Our results also show that the human basilar artery seems to have a mixed population of 5-HT1B/1D receptors mediating the contractile response to triptans, which is also suggested by the expression of both receptor subtypes. There is also a population of 5-HT2 receptors for which the antimigraine drugs used have no apparent affinity. From this study, one can conclude that the second generation triptans have lower contractile capacity than sumatriptan, suggesting that they have a better cerebrovascular safety profile.

Focus on trial endpoints of clinical relevance and the use of almotriptan for the acute treatment of migraine

Almotriptan is a 5-HT(1B/1D) receptor agonist, or triptan, indicated for the acute treatment of migraine. It has been shown to be effective and well tolerated for the treatment of acute migraine in approximately 5000 patients enrolled in short-term placebo- and active-controlled trials and long-term open-label trials. A recent meta-analysis reported that almotriptan has the highest sustained pain-free (SPF) rate and lowest adverse-event (AE) rate of all oral triptans. Sustained pain free is a composite endpoint of pain freedom at 2 h, no recurrence of moderate-to-severe headache and no use of rescue medication from 2 to 24 h after dosing. Patient surveys have indicated that migraine sufferers consider complete pain relief, no recurrence, rapid onset and no side-effects to be the most important attributes of their acute treatment. Composite endpoints such as SPF and SPF with no AEs (SNAE) contain the attributes that migraine sufferers express as being the most important elements of an acute migraine therapy, and their use in future clinical trials should aid in the selection of agents that can offer patients the highest likelihood of consistent treatment success.

Clinical data on the CGRP antagonist BIBN4096BS for treatment of migraine attacks

Basal studies have shown that calcitonin gene-related peptide (CGRP) is a major sensory neuronal messenger in the trigeminovascular system, the pathway conveying intracranial pain. In migraine and cluster headache attacks, CGRP is released in parallel with the pain and successful treatment of the attacks abort both the associated pain and the CGRP release. The search for a potent small molecule CGRP antagonist has been successful and such an agent has been tested in preclinical and clinical studies. The aim of the present study was to examine current knowledge on the clinical pharmacology of systemic BIBN4096BS, which has been shown in man to abort acute migraine attacks as well or better than oral sumatriptan. BIBN4096BS is a specific and potent CGRP receptor antagonist in humans. In safety and tolerability studies the substance is well tolerated with no or only mild side effects. In acute migraine attacks the overall response was 66% with the drug and 27% with placebo. A difference as compared to placebo was seen at 30 min; the response was still rising at 4 h suggesting a long duration of action. At 24 h the pain-free rate was better than that with triptans, suggesting a lower grade of rebound and perhaps even a prophylactic possibility.

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

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

Cardiovascular Risk Assessment and Triptans

Identifying the patient for whom triptans are contraindicated because of recognized, diagnosed cardiovascular disease is relatively straightforward. Determining whether a patient with potential unrecognized cardiovascular disease is an appropriate candidate for triptan therapy, however, constitutes a difficult challenge, especially in the absence of a framework for workup of patients. This article discusses the pathophysiology of coronary heart disease and issues involved in assessing cardiovascular risk, and it attempts to provide a framework for cardiovascular risk assessment that can be applied to decisions for prescribing triptans. Current guidelines for cardiovascular risk assessment allow stratification of patients to low, intermediate, or high risk of coronary heart disease events. This framework for risk assessment can be applied to decisions for prescribing triptans. Cardiovascular risk-assessment algorithms discussed elsewhere in this supplement suggest that patients at low risk (1 or no risk factors) of coronary heart disease can be prescribed triptans without the need for a more intensive cardiovascular evaluation. Conversely, patients with established coronary heart disease or coronary heart disease risk equivalents should not be prescribed triptans according to the current prescribing recommendations. Patients at intermediate risk (2 or more risk factors) of coronary heart disease require cardiovascular evaluation before triptans can be prescribed. Current understanding suggests that the risk of future acute coronary events is a function of the absolute number of vulnerable plaques present, a variable that cannot be accurately determined using available technology or risk-prediction models. Cardiovascular risk-assessment guidelines should be evaluated in the context of this limitation.