Triptans and migraine

Patent foramen ovale

Patent foramen ovale (PFO) is the most common anatomical cause of an interatrial shunt. It is usually asymptomatic but may cause paradoxical embolism, manifesting as stroke, myocardial infarction or visceral/peripheral ischaemia. PFO is a risk factor for stroke and may be associated with migraine with aura. New evidence suggests PFO closure reduces the risk of recurrent ischaemic stroke in a highly selected population of stroke survivors: those aged 60 years or younger with a cryptogenic stroke syndrome, a large right-to-left shunt, an atrial septal aneurysm and no evidence of atrial fibrillation. They benefit from percutaneous PFO closure in addition to antiplatelet therapy, rather than antiplatelet therapy alone. Current evidence does not support PFO closure in the treatment of migraine.

Migraine with aura and persistent foramen ovale

The association between migraine with aura and persistent foramen ovale (PFO), as well as other right-to-left shunts, is described. A hypothesis that might explain this association is discussed. Observational studies suggested that when a PFO is closed patients who have migraine with aura are usually improved. The Migraine Intervention with STARFlex Technology (MIST) Trial was a randomised double-blind trial in patients with severe intractable migraine with aura and a moderate-large PFO that compared implantation of STARFlex devices with the intention of closing their PFO versus a sham procedure. It was hoped that the trial would demonstrate whether PFO closure would cure migraine. A series of problems in design and execution of the trial are discussed.

Naratriptan Has a Selective Inhibitory Effect on Trigeminovascular Neurones at Central 5-HT1A and 5-HT1B/1D Receptors in the Cat: Implications for Migraine Therapy

The triptans are agonists at serotonin(5-HT) 1B/1D receptors; however, they are also active at 5-HT1A and 5-HT1F receptors. We conducted this series of experiments to further elucidate the site of action of naratriptan using a well-established animal model of trigeminovascular stimulation. Following electrical stimulation of the superior sagittal sinus of the cat, single cell responses ( n = 83) were recorded in the trigeminal nucleus caudalis. Most cells (91%) also responded to electrical and mechanical stimulation of cutaneous or mucosal facial receptive fields. The micro-iontophoretic application of naratriptan resulted in a significant suppression of the response to sagittal sinus stimulation (response suppressed by 47 ± 4%, P < 0.001). The effect of naratriptan was significantly attenuated by application of either the 5-HT1B/1D receptor antagonist GR-127935 ( P < 0.001) or the 5-HT1A antagonist WAY-100635 ( P < 0.05). The response of single cells to receptive field stimulation was also suppressed by microiontophoretic application of naratriptan, but by only 20 ± 3%. Intravenous administration of naratriptan resulted in a similar selective suppression of sagittal sinus vs. receptive field responses in trigeminal neurones. These results indicate that naratriptan has a central effect in the trigeminovascular system, selectively inhibiting afferent activity in craniovascular neurones, via both 5-HT1B/1D and 5-HT1A receptors.

The Practice Pattern of Migraine Management among Neurologists in Taiwan

To assess the prevalence of migraine and the attitudes and practice patterns of Taiwanese neurologists regarding migraine management, we mailed the survey questionnaire to all of the actively practicing board-certified neurologists from the membership list of the Taiwan Neurological Association. Of the targeted 531 neurologists, 123 (23.2%) participated in this study. Thirty of the participants (27.6%) reported having migraine. Most neurologists (88.5%) felt that headache was an important part of their practice. Many neurologists (65.0%) used neuroim- aging to evaluate patients with severe headache and 44.7% used electroencephalography for headache evaluation. Many participants knew that combination analgesic was a common cause of medication-overuse headache, but did not know that ergotamine, acetaminophen and triptans were possible aetiologies of medication-overuse headache. Our study suggests that awareness of medication- overuse headache and the indications of neuroimaging should be stressed in Taiwan, and headache guidelines should be modified according to local factors.

Patent foramen ovale and migraine

Migraine is a common neurological disorder with a great impact on the quality of life and social activities. The patent foramen ovale (PFO) is an intra-atrial right-to-left shunt with a prevalence of 25% in the general population. An increased prevalence is found in patients with migraine, especially in migraine with aura. Percutaneous PFO closure might decrease the prevalence of migraine. However, most of these observational studies were retrospective without a randomized design and the results need to be interpreted with caution. In this review we describe the association between PFO and migraine and the different pathophysiological hypotheses, which have been proposed to explain this relationship.

The Role of Cardiac and Pulmonary Pathology in Migraine: A Hypothesis

From observation of recent data linking migraine with right-to-left shunts and by analogy with the etiologies of decompression illness, we postulate that cardiac and pulmonary pathology can have an important effect on the cranial final common pathway that generates attacks of migraine. One possible mechanism is associated with a significant right-to-left shunt, which is usually through a persistent foramen ovale, but is sometime through a pulmonary shunt. This allows a venous agent, possibly 5-hydroxytryptamine, to bypass the lung filter. Migraine can occur when there is no shunt if similar agents are liberated in the left heart beyond the lung filter, possibly by platelet activation. Migraine could also occur if the venous agents are produced in such large amounts that they overwhelm the pulmonary filter or are unaffected by passage through the lungs. In some individuals migraine may be unrelated to blood-borne triggers.

Efficacy of oral naratriptan in the treatment of menstrually related migraine

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

The persistent foramen ovale and migraine

There is association between migraine, particularly migraine with aura, and large persistent foramen ovale (PFO) and other right-to-left shunts. Migraine is often improved by closure of a PFO in patients who have a large shunt. Inheritance of migraine is linked to the inheritance of large atrial shunts in some families. The data indicate that in some patients PFOs play a causal role in migraine with aura. These observations may also improve understanding of the etiology of migraine in patients who do not have a shunt.

Propofol: a new treatment strategy for refractory migraine headache

Migraine headache remains a treatment dilemma in headache clinics, pain clinics, and emergency departments throughout the country. In the late nineties, investigators reported that a standard hypnotic anesthetic, propofol (2,6 di-isopropylphenol), dramatically improved pain scores of patients suffering from refractory migraine headaches. Case reports over the last few years have appeared in the medical literature describing the use of propofol for migraine treatment. Dosing regimens are not clear, and mechanisms of action to terminate or markedly curtail ongoing intractable headaches are not described. This case report, of two hospitalized patients with refractory migraine, increases the existing literature on the use of propofol therapy in migraine headache. In the first case, three different scenarios and dosages are described in the same patient. In the second case, the use of different dosages of propofol is described. A self-reported scale was employed by the patients to determine the efficacy of propofol therapy. In the first case, the patient's self-reported migraine score was an average of 100/100 and decreased to 10/100. In the second case, the patient's self-reported migraine score improved from 92/100 to 40/100. We propose that the improvements in the self-reported migraine score in both patients after propofol therapy may be due to GABAA agonist effects and cerebral vasoconstriction.

Use and misuse of triptans in France: data from the GRIM2000 population survey

The extent and nature of triptan use for headache relief has been evaluated in a large epidemiological survey in the French general population. Over 25 000 individuals were screened for headache and for triptan use. Of this sample, 290 triptan users were identified from whom extensive data on headache characteristics and healthcare resource consumption were obtained. The use of triptans is relatively infrequent, 0.2% in the general population, with only 7.5% of migraine sufferers using these drugs. The majority of triptan users were female (80%) and presented headache characteristics typical of migraine (80%). The remaining 20% of subjects were thus using triptans for headache types in which the utility of these drugs has not been demonstrated. Among migraineurs, triptan consumers reported more frequent and severe headaches than non-consumers, and reported a higher incidence of nausea and vomiting. The principal determinant of triptan prescription was consultation with a general practitioner (GP), which may itself have been triggered by the severity of the headaches. GPs, rather than specialists, are the primary prescribers of triptans in France.

Cost Considerations of Acute Migraine Treatment

OBJECTIVE

To provide medication price data and cost-reducing strategies for the acute treatment of migraine.

METHODS

Retail prices for common acute care medications were found at http://www.drugstore.com. Cost-reduction tactics were obtained from literature searches and clinical experience.

RESULTS

Several strategies can reduce cost without sacrificing treatment outcome. In mild to moderate migraine, low-priced nonsteroidal anti-inflammatory drugs can be used as first-line medications due to their proven efficacy and favorable tolerability. For patients with more severe migraine, implementing a stratified care approach-using migraine-specific medications early in acute treatment-is cost-effective for most patients. Stratified care not only improves outcome and decreases disability, but also reduces cost. Pill splitting and early administration of triptans within an attack enhance their value. Supplying rescue medications, such as opioids, sedatives, and phenothiazines, can prevent emergency department visits. Minimizing multiple dosing of triptans and reducing utilization of expensive health care resources are key factors in reducing the cost of effective migraine treatment. An important affordability factor for patients with co-payments is the number of triptan pills per package. Sumatriptan, naratriptan, and frovatriptan each contain 9 tablets per package, while most other triptan packages contain 6. Current triptan retail prices (per unit) include: Amerge 1 and 2.5 mg, 17.78 dollars; Axert 6.25 and 12.5 mg, 16.31 dollars; Frova 2.5 mg, 13.89 dollars; Imitrex 50 mg, 14.96 dollars; Imitrex 100 mg, 14.41 dollars; Imitrex Nasal Spray 20 mg, 21.61 dollars; Imitrex SQ 6 mg, 50.26 dollars; Maxalt 5 and 10 mg, 15 dollars; Maxalt-MLT 5 and 10 mg, 15 dollars; Relpax 40 mg, 13.58 dollars; Zomig 2.5 mg, 13.67 dollars; Zomig 5 mg, 15.89 dollars; Zomig-ZMT 2.5 mg, 13.67 dollars; and Zomig-ZMT 5 mg, 15.89 dollars.

CONCLUSIONS

Practitioners can optimize the use of health care dollars without compromising quality of care through awareness of cost-saving treatment strategies, as well as price variations among medications.

Economic impact of migraine and other episodic headaches in France: data from the GRIM2000 study

BACKGROUND

Migraine is a prevalent and incapacitating condition that affects individuals in the prime of their productive life, thus generating an economic burden for both society and healthcare systems. The direct annual healthcare costs of migraine in France were assessed over 10 years ago, and the current study updates these figures.

OBJECTIVE

The objective of this study was to determine the economic cost (primarily direct costs) of migraine and other episodic headache in France based on a general population survey of headache, the GRIM2000 (Groupe de Researche Interdisciplinaire sur la Migraine).

DESIGN

From a representative general population sample of 10,585 individuals aged > or = 15 years in France in 1999, 1486 individuals experiencing headaches were identified and interviewed regarding healthcare resource consumption in the previous 6 months. By applying unit costs to the resource data, costings (in 1999 values) were determined for physician consultations, hospitalisation, medication use and diagnostic/laboratory tests, and evaluated from a healthcare system perspective. Information on absenteeism and lost productivity was derived from the Migraine Disability Assessment Score (MIDAS) questionnaire.

RESULTS

The prevalence of migraine (including migrainous disorder) was determined to be 17%. Total annual direct healthcare costs were estimated to be Euros 128 per individual with migraine in 1999, corresponding to Euros 1044 million when extrapolated to all individuals experiencing migraine and aged > or = 15 years. Around two-thirds of this cost accrued to the social security system (Euros 698 million; Euros 85 per individual). The total annual direct cost of other forms of episodic headache was much lower at Euros 28 per individual (social security cost Euros 18); with a prevalence of 9.2%, the annual national direct cost for other forms of episodic headache totalled Euros 124 million. The principal cost element was physician consultations. However, it was found that many individuals had never consulted a physician for their headaches, and self-medication contributed substantially to the medication costs (the second greatest cost factor for migraine). The cost per individual rose steeply with increasing severity of headache.

CONCLUSIONS

The direct healthcare costs of migraine do not seem to have risen significantly over the past decade. A small minority of individuals with more severe headaches consume most of the healthcare resources devoted to migraine, while most individuals generate relatively low direct costs. The total annual direct costs in France for migraine are almost 10-fold higher than those of other episodic headache.

A delayed class of BOLD waveforms associated with spreading depression in the feline cerebral cortex can be detected and characterised using independent component analysis (ICA)

An application of independent component analysis to blood oxygenation level- dependent MRI (BOLD-MRI) results was used to detect cerebrovascular changes that followed the initiation of cortical spreading depression (CSD) in feline brain. The cortical images were obtained from a horizontal plane at 28 s intervals before, and for 1.4-1.75 h after, KCl dissolved in agar (KCl/agar) had been directly applied to the left suprasylvian gyrus of 13 anesthetized cats for 10 min. It successfully resolved, for the first time, a novel class of prolonged, and delayed, biphasic BOLD waveforms. These were larger in amplitude ( approximately 20%), longer lasting and more delayed in onset (13-33 min) than the brief propagating (90 s) BOLD increase ( approximately 4%) already known to be associated with CSD on earlier occasions. Furthermore, such changes occurred in localized regions on the hemisphere ipsilateral to the site of stimulus application in 4 out of 5 control subjects rather than themselves generating propagating waves. Finally, the biphasic waveforms were consistently abolished in the 4 experimental animals studied following the i.v. administration of sumatriptan (0.3 mg kg(-1)), an antimigraine 5-HT(1B/1D) agonist, 15 min before the application of the transient stimulus. They were abolished in 2 out of 4 animals following the intraperitoneal (i.p.) administration of SB-220453 (tonabersat: 10 mg kg(-1), 90 min before stimulus application), a novel anticonvulsant that has recently been reported to inhibit CSD. ICA has thus been successful in detecting a novel localized, as opposed to propagating, signal of potential physiological significance hidden in complex BOLD- MRI data, whose sensitivity to sumatriptan may relate it to the cerebrovascular changes reported in the headache phase of migraine.

Comparative aspects of triptans in treating migraine

Triptans, beginning with sumatriptan, have revolutionized the treatment of migraine. New triptans in several formulations will soon become available in the United States. Although the similarities of these 5-hydroxytryptamine (5-HT) 1B/1D receptor agonists outweigh their differences, important differences in pharmacokinetics and clinical responses do exist. Subcutaneous sumatriptan has the most rapid onset of action and greatest efficacy but the most adverse effects. Intranasal sumatriptan also has rapid onset of action, but at 2 hours its efficacy is comparable to that of oral zolmitriptan. Of the oral triptans, rizatriptan seems to have the greatest early efficacy. Both rizatriptan and zolmitriptan are now available as rapidly dissolving wafers. Almotriptan, the newest of the triptans, has a response rate similar to that of oral sumatriptan and may produce fewer adverse effects. Naratriptan and frovatriptan, with their slow onset, high tolerability, and long half-lives, may have a role in aborting prolonged migraine attacks and in headache prevention. Eletriptan at higher doses (80 mg) has a response rate approaching that of rizatriptan but may be limited by potential side effects. The many triptans available offer the opportunity to individualize migraine treatment, depending on the patient's attack characteristics, tolerance, and preferences.

Diffusion-weighted MRI used to detect in vivo modulation of cortical spreading depression: comparison of sumatriptan and tonabersat

Spreading cortical depolarization and depression of electroencephalographic activity (SD) may underlie the aura and spreading neurovascular events of migraine. Cortical depolarization may also precipitate the progressive development of cerebral pathology following ischemia. However, data on SD in the human brain are sparse, most likely reflecting the technical difficulties involved in performing such clinical studies. We have previously shown that the transient cerebral water disturbances during SD can be quantitatively investigated in the gyrencephalic brain using repetitive diffusion-weighted magnetic resonance imaging (DWI). To investigate whether DWI could detect modulation of the spatiotemporal properties of SD in vivo, the effects of the antimigraine drug sumatriptan (0.3 mg/kg iv) and the novel anticonvulsant tonabersat (10 mg/kg ip) were evaluated in the cat brain. Supporting previous findings, sumatriptan did not affect the numbers of events (range, 4-8), the duration of SD activity (39.8 +/- 4.4 min, mean +/- SEM), and event velocity (2.2 +/- 0.4 mm min(-1)); tonabersat significantly reduced SD event initiation (range, 0-3) and duration (13.2 +/- 5.0 min) and increased primary event velocity (5.4 +/- 0.7 mm min(-1)). However, both drugs significantly decreased, by >50%, the spatial extent of the first KCl-evoked SD event, and sumatriptan significantly increased event propagation across the suprasylvian sulcus (5.5 +/- 0.6 vs 2.4 +/- 0.4 events in controls). These results demonstrate (1) the feasibility of using DWI to evaluate therapeutic effects on SD, and (2) that sumatriptan may directly modulate the spatial distribution of SD activity in the gyrencephalic brain.

Vascular effects of the new anti-migraine agent almotriptan on human cranial and peripheral arteries

This paper describes the vascular effects of almotriptan in comparison with sumatriptan in human vessels and tissues in vitro. The contractile properties of almotriptan and sumatriptan were evaluated in vitro in the following arteries: meningeal, temporal, basilar, internal carotid, ophthalmic, pulmonary and coronary. In addition, the effects of almotriptan on the pulmonary vein and on bronchial tissues were studied. Almotriptan showed selectivity of action for migraine-related arteries (i.e. contractile EC(50) of 30 and 700 nm for meningeal and temporal arteries, respectively), whereas the effect on arteries supplying blood to the brain was lower. The contractile effect of almotriptan was lower than that of sumatriptan in pulmonary arteries, whereas in bronchial preparations no clinically relevant contractile responses were observed for either almotriptan or sumatriptan. In ophthalmic arteries the contractile effects of almotriptan and sumatriptan were similar, whereas lower contractile effects were obtained with almotriptan than with sumatriptan in coronary arteries.

Effect of intranasal sumatriptan on gastric tone and sensitivity to distension

Sumatriptan is able to improve symptoms of early satiety in dyspeptic patients by relaxing the gastric fundus. The aim of this study was to verify the efficacy of intranasal administration of sumatriptan on gastric sensory motor function, in order to provide a new pharmacotherapeutic approach to functional dyspepsia. Thirteen healthy subjects were investigated twice on separate days. A gastric barostat was used to study the effect of placebo and sumatriptan, 20 mg intranasally, on basal fundic tone. In addition, stepwise isobaric distensions were performed and perception was measured before and after administration of drugs. Placebo had no effect on gastric tone and on perception. Sumatriptan caused a small, but short-lasting gastric relaxation and had no significant effect on sensitivity to distension and gastric compliance. Unlike the subcutaneous formulation, the intranasal administration of sumatriptan had no effect on gastric sensory motor functions, and this probably reflects a low biovailability of intranasally administered sumatriptan.

Current options for the prevention and treatment of migraine

BACKGROUND

Migraine is a common condition affecting approximately 18% of women and 6% of men in the United States. The goals of managing migraine are 2-fold: to prevent attacks from occurring and to effectively and rapidly end them when they do occur.

OBJECTIVE

This article reviews the acute and prophylactic treatment of migraine.

METHODS

Information for inclusion in this review was identified through a search of MEDLINE from 1995 to the present. Search terms included migraine, acute treatment, prophylactic treatment, preventive treatment, and individual drug names.

RESULTS

Preventive measures for migraine include lifestyle changes (eg, avoiding migraine triggers and maintaining regular sleep, eating, and work habits) and drug therapy. Beta-blockers, calcium channel blockers, tricyclic antidepressants, and anticonvulsants are among the more common drug classes used for migraine prophylaxis, but preventive therapy must be individualized, taking into account efficacy, potential adverse effects, co-existing medical conditions, and drug costs. Many medications are available for the acute treatment of migraine, including over-the-counter analgesics and prescription drugs. Of the latter, the 5-hydroxytryptamine(1B/1D)-receptor agonists, or triptans, are the most recently introduced class. Each of the 4 available triptans (sumatriptan, zolmitriptan, naratriptan, and rizatriptan) is effective in ending a migraine attack, but comparative trials have shown differences between individual drugs in the time to pain relief and the percentage of patients who obtain pain relief.

CONCLUSIONS

Medications to prevent or reduce the frequency of migraine tend to be less specific and effective than medications for the acute treatment of migraine. As a class, triptans are generally well tolerated and may be considered drugs of choice for the acute treatment of moderate to severe migraine.

Hemodynamic and electrocardiographic effects of almotriptan in healthy volunteers

We studied the possible cardiovascular effects of single oral doses of 12.5, 25, and 50 mg of almotriptan, a new triptan for treatment of migraine, in a randomized, double-blind, four-way crossover, placebo-controlled study in 24 healthy volunteers aged 18 to 35 years. Doses were given at 1-week intervals. Cardiovascular effects were assessed by frequent recording of blood pressure and heart rate, 12-lead electrocardiogram (ECG) (recorded at 25 mm/s paper speed and 1 cm/mV and at 50 mm/s and 2 cm/mV), and continuous ECG monitoring for 12 h after each dose. ECG variables, PR, QRS, QT interval, and QT dispersion, were measured. QT intervals were adjusted for heart rate using Bazett's formula. None of the doses of almotriptan differed significantly from placebo with respect to PR, QRS, or QTc intervals, QTc dispersion, heart rate, or continuous ECG monitoring. Almotriptan 12.5 mg did not differ significantly from placebo with respect to systolic or diastolic blood pressure, but almotriptan 25 and 50 mg raised systolic blood pressure by a mean of 2.78 and 4.17 mm Hg, and diastolic blood pressure by 3.77 and 6.11 mm Hg, respectively, during 0 to 4 h after dosing. Thus none of the doses of almotriptan affected the ECG, and the 12.5-mg dose (the expected therapeutic dose) had no hemodynamic effects. Almotriptan in doses of 25 and 50 mg caused a small, dose-related increase in systolic and diastolic blood pressure, as seen with other triptans.

Gastric motor effects of triptans: open questions and future perspectives

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