Coronary side-effect potential of current and prospective antimigraine drugs

BACKGROUND

The antimigraine drugs ergotamine and sumatriptan may cause angina-like symptoms, possibly resulting from coronary artery constriction. We compared the coronary vasoconstrictor potential of a number of current and prospective antimigraine drugs (ergotamine, dihydroergotamine, methysergide and its metabolite methylergometrine, sumatriptan, naratriptan, zolmitriptan, rizatriptan, avitriptan).

METHODS AND RESULTS

Concentration-response curves to the antimigraine drugs were constructed in human isolated coronary artery segments to obtain the maximum contractile response (Emax) and the concentration eliciting 50% of Emax (EC50). The EC50 values were related to maximum plasma concentrations (Cmax) reported in patients, obtaining Cmax/EC50 ratios as an index of coronary vasoconstriction occurring in the clinical setting. Furthermore, we studied the duration of contractile responses after washout of the acutely acting antimigraine drugs to assess their disappearance from the receptor biophase. Compared with sumatriptan, all drugs were more potent (lower EC50 values) in contracting the coronary artery but had similar efficacies (Emax <25% of K+-induced contraction). The Cmax of avitriptan was 7- to 11-fold higher than its EC50 value, whereas those of the other drugs were <40% of their respective EC50 values. The contractile responses to ergotamine and dihydroergotamine persisted even after repeated washings, but those to the other drugs declined rapidly after washing.

CONCLUSIONS

All current and prospective antimigraine drugs contract the human coronary artery in vitro, but in view of low efficacy, these drugs are unlikely to cause myocardial ischemia at therapeutic plasma concentrations in healthy subjects. In patients with coronary artery disease, however, these drugs must remain contraindicated. The sustained contraction by ergotamine and dihydroergotamine seems to be an important disadvantage compared with sumatriptan-like drugs.

Clinical features of withdrawal headache following overuse of triptans and other headache drugs

BACKGROUND

Complete withdrawal from headache medication is the treatment of choice for medication-overuse headache. Discontinuation of the overused headache medication, however, results in the development of withdrawal headache, often associated with nausea, vomiting, and sleep disturbances.

METHOD

In a prospective study of 95 patients, the authors investigated the duration and severity of withdrawal headache after overuse of various headache drugs, including single and combination analgesics, ergots, and triptans. All patients underwent standard inpatient withdrawal therapy for 14 days.

RESULTS

The duration of withdrawal headache was shorter in patients overusing triptans (4.1 days) than in patients overusing ergots (6.7 days) or analgesics (9.5 days; p < 0.002). The mean headache intensity on the first day of withdrawal did not differ between the groups (p = 0.821). By day 14, however, it was lower in patients overusing triptans (0.08) than in patients overusing ergots (0.4) or analgesics (0.9; p < 0.005). Rescue medication was requested less by patients undergoing triptan withdrawal (0.25 requests) than by patients undergoing ergot withdrawal (1.25) or analgesic withdrawal (1.85; p < 0.05). Similar to findings in the entire patient population, withdrawal headache was shorter and less severe in migraineurs overusing triptans than in those overusing ergots or analgesics. Because only patients with migraine, but no patient with tension-type headache, overused triptans, withdrawal headache was shorter in the group of patients with migraine alone (6.7 days versus 9.6 days for patients with tension-type headache and 8.5 days for patients with combination headache, p < 0.02).

CONCLUSION

The duration and severity of withdrawal clearly depend on the type of overused headache drug only.

A randomized, double-blind comparison of sumatriptan and Cafergot in the acute treatment of migraine. The Multinational Oral Sumatriptan and Cafergot Comparative Study Group

The efficacy and safety of oral sumatriptan as a 100-mg dispersible tablet was compared with oral Cafergot (2 mg ergotamine tartrate, 200 mg caffeine) in a multicentre, randomized, double-blind, double-dummy, parallel-group trial. In the trial, 580 patients were treated from 47 investigating centres in nine European countries. Sumatriptan was significantly more effective than Cafergot at reducing the intensity of headache from severe or moderate to mild or none; 66% (145/220) of those treated with sumatriptan improved in this way by 2 h, compared with 48% (118/246) of those treated with Cafergot (p less than 0.001). The onset of headache resolution was more rapid with sumatriptan, whereas recurrence of migraine headache within 48 h was lower with Cafergot. Sumatriptan was also significantly more effective at reducing the incidence of nausea (p less than 0.001), vomiting (p less than 0.01) and photophobia/phonophobia (p less than 0.001) 2 h after treatment, and fewer patients on sumatriptan (24%) than on Cafergot (44%, p less than 0.001) required other medication after 2 h. The overall incidence of patients reporting adverse events was 45% after sumatriptan and 39% after Cafergot; the difference was not significant. The most commonly reported events in the sumatriptan-treated patients were malaise or fatigue and bad taste; these were generally mild and transient. Nausea and/or vomiting, abdominal discomfort, and dizziness or vertigo were reported by a greater proportion of Cafergot-treated patients. It is concluded that oral sumatriptan was well tolerated and is a more effective acute treatment for migraine than Cafergot.

Transformed migraine

Chronic tension-type headache, which is included in the International Headache Classification, is present in only a minority of patients who present with chronic daily headache. The majority have what is termed transformed migraine, with a history of distinct episodes of migraine in the initial years which progresses into chronic daily headache. These patients with transformed migraine exhibit mixed features of migraine and chronic tension-type headache. Two distinct types of transformed migraine are identifiable, namely those related to excessive intake of medications (drug-induced transformed migraine) and those unrelated to excessive use of medications. The clinical features of transformed migraine and the drug-induced variety are described. The need for revision of the International Classification to include chronic daily headache and the subtypes of transformed migraine is pointed out.

Longterm prognosis of analgesic withdrawal in patients with drug-induced headaches

We studied long-term prognosis and prognostic variables for therapeutic outcome of analgesic withdrawal in 54 patients with drug-induced headaches. The duration of headache history was 21.9 +/- 12.8 years. Each patient took an average of 38.8 +/- 22.8 tablets or suppositories a week and an average of 2.5 distinct drugs. Most patients used drugs containing several components. Caffeine was contained in at least one drug in all cases, ergotamine in 80.0% and pyrazolone in 77.1%. All patients were admitted to the hospital for two weeks. The analgesics were discontinued abruptly and the withdrawal symptoms were alleviated by neuroleptics and neurotropics. During the second week of hospital stay we started a basic therapy with calcium antagonists or beta blockers in patients suffering from migraine initially and with tricyclic antidepressants, physical therapy or biofeedback in patients suffering from tension type headaches initially. At the end of the study (mean follow-up period = 16.8 +/- 13.6 months) 38 patients (70.1%) were evaluated. 76.3% of these patients had significantly reduced their analgesic intake, 60.5% had experienced a significant relief of headache both in intensity and frequency, and 23.7% were therapeutic failures. Analysis of the time course of relapse revealed the first six months after hospital discharge as the critical period determining long-term success. The variables tested for prognostic relevance (age, sex, duration of headache history, number of tablets or suppositories taken a week, organic mental syndrome, and type of initial headaches) were not statistically significant.

Drug-induced fibrotic valvular heart disease

The initial association between the development of valvular heart disease and drugs stems from observations made during the use of methysergide and ergotamine for migraine prophylaxis in the 1960s. Since then, the appetite suppressants fenfluramine and dexfenfluramine, the dopamine agonists pergolide and cabergoline, and more recently, the recreational drug ecstasy (3,4 methylenedioxymethamphetamine; MDMA) have been implicated. Results from clinical trials show that drug dose and treatment duration affect both the risk of developing the disease and its severity. The natural history of the disease remains unclear, although regression of valvular lesions after the end of treatment has been reported. Interference with serotonin metabolism and its associated receptors and transporter gene seems a likely mechanism for development of the drug-induced valvular heart disease. Physicians need to balance the benefits of continued therapy with these drugs against possible risks. Further investigation is needed to assist with treatment decisions. Continued vigilance is necessary because several commonly prescribed treatments interact with serotonergic pathways.

Long-term outcome of patients with headache and drug abuse after inpatient withdrawal: five-year follow-up

Thirty-eight patients with "chronic daily" headache and ergotamine and/or analgesics abuse according to the criteria proposed by the International Headache Society were re-investigated 5 years after inpatient drug withdrawal. At the end of the observation period, 19 patients (50.0%) had their headaches on only 8 days per month or less, 18 patients (47.4%) were free of symptoms or had only mild headaches. A close correlation was found between the frequency of headache and the duration of drug abuse, as well as between the intensity of headache and the number of tablets taken per month. Frequency and intensity of headache had changed within the first 2 years after withdrawal, but remained stable afterwards. Fifteen patients (39.5%) reported on recurrent drug abuse. Patients with migraine showed a tendency towards a better prognosis compared to patients with tension-type headache or with combined migraine and tension-type headache. The results of this study highlight the long-term efficacy of inpatient drug withdrawal in patients with headache and ergotamine and/or analgesics abuse.

Efficacy, tolerability and safety of oral eletriptan and ergotamine plus caffeine (Cafergot) in the acute treatment of migraine: a multicentre, randomised, double-blind, placebo-controlled comparison

The 5-HT(1B/1D/1F) agonist eletriptan, at an oral dose of 80 mg, has been shown to be more efficacious than sumatriptan 100 mg and placebo in the treatment of migraine attacks with or without aura. Another commonly prescribed oral treatment for migraine attacks is Cafergot (1 mg ergotamine tartrate with 100 mg caffeine per tablet). The efficacy, tolerability and safety of 40- and 80-mg doses of eletriptan and 2 tablets of Cafergot were compared in a double-blind, randomised, placebo-controlled, parallel-group trial involving 733 migraine patients. Patients recorded symptoms at baseline (before treatment) and 1, 2, 4 and 24 h after dosing. Headache intensity was assessed on a 4-point scale (3 = severe pain, 2 = moderate pain, 1 = mild pain, 0 = no pain). Significantly more eletriptan-treated patients (80 mg, 68%; 40 mg, 54%) than Cafergot-treated patients (33%; p < 0.001) reported headache response (improvement from moderate-to-severe to mild or no pain) at 2 h. Substantially more eletriptan recipients reported no pain (80 mg, 38%; 40 mg, 28%; Cafergot, 10%; placebo, 5%; p < 0.001). Eletriptan headache response rates at 1 h were significantly higher (80 mg, 39%; 40 mg, 29%; Cafergot, 13%; placebo, 13%; p < 0.002 for each comparison). Both doses of eletriptan were significantly more effective than Cafergot in reducing nausea (p < 0.0001), photophobia (80 mg, p < 0.0001; 40 mg, p < 0.002), phonophobia (80 mg, p < 0.0001; 40 mg, p < 0.003) and functional impairment (p < or = 0.001) at 2 h. Adverse events were generally mild or moderate and transient. This randomised trial shows that oral eletriptan is more efficacious in the acute treatment of migraine than oral Cafergot and is well tolerated.

Medications associated with probable medication overuse headache reported in a tertiary care headache center over a 15-year period

OBJECTIVES

To evaluate the substances associated with medication overuse headache (MOH) in a headache center, over the course of the past 15 years.

BACKGROUND

The acute treatment of migraine has substantially changed over the past 15 years, and therefore, the substances associated with MOH may have changed as well.

METHODS

We randomly reviewed charts of subjects seen during the years of 2005, 2000, 1995, and 1990, to identify substances associated with MOH. Since the criteria proposed by the second edition of the International Classification of Headache Disorders require causal attribution, demonstrated by improvement after withdrawal (and this was not assessed in this study), herein we refer to probable MOH (PMOH). We contrasted the substances associated with PMOH over the studied years.

RESULTS

Our sample consists of 1200 individuals, 300 per year of interest. The proportions of subjects with a diagnosis of PMOH remained stable over the years, varying from 64% of all cases seen in the center in 1990, to 59.3% in 2005. We found a significant decrease in the relative frequency of probable ergotamine overuse headache (from 18.6% to 0%, P < .0001), and in probable combination analgesic overuse headache (from 42.2% to 13.6%, P < .0001). The differences were not significant for opioid overuse headache. The relative frequency increased significantly for the triptans (from 0% to 21.6%, P < .0001), simple analgesics (from 8.8% to 31.8%, P < .05), and for combinations of acute medications (from 9.8% to 22.7%, P = .01).

CONCLUSION

While overuse of acute medications remains an important problem in the tertiary care arena, the substances associated with the overuse have dramatically changed over the past 15 years. Educational initiatives should emphasize that the newer specific acute migraine medications (triptans) may also be associated with PMOH.

Abrupt outpatient withdrawal of medication in analgesic-abusing migraineurs

46 migraineurs with secondary chronic daily headache were treated for medication abuse as outpatients by abrupt withdrawal of the offending drugs. The patients were supported with adequate explanation of the disorder, regular follow-up, amitriptyline (10 mg at night), and naproxen (500 mg) for relief of headache symptoms. By 6 months of follow-up 37 patients had relief from chronic headaches, and analgesic intake had become intermittent and appropriate to the original occasional migraine episodes. 6 had substantially reduced analgesic intake, but headache severity was unchanged; 2 had not managed to reduce intake and headache was unchanged; and 1 patient withdrew after the first visit.

Tolfenamic acid is as effective as ergotamine during migraine attacks

Tolfenamic acid (a potent inhibitor of prostaglandin biosynthesis), ergotamine tartrate, acetylsalicylic acid, or placebo was administered during 160 migraine attacks in twenty women in a double-blind, cross-over study. Tolfenamic acid and ergotamine were equally effective in reducing the duration and intensity of attacks, but side-effects, especially nausea, were less common with tolfenamic acid. This probably accounted for the patients' preference for tolfenamic acid. The effectiveness of tolfenamic acid in acute migraine attacks accords with the postulated role of prostaglandins in migraine.

Ergotamine and dihydroergotamine: a review

The ergot alkaloids were the first specific antimigraine therapy available. However, with the advent of the triptans, their use in the treatment of migraine has declined and their role has become less clear. This review discusses the pharmacology, efficacy, and safety of the ergots. In randomized clinical trials, oral ergotamine was found to be superior to placebo, but inferior to 100 mg of oral sumatriptan. In contrast, rectal ergotamine was found to have higher efficacy (73% headache relief) than rectal sumatriptan (63% headache relief). Intranasal dihydroergotamine was found to be superior to placebo, but less effective than subcutaneous and intranasal sumatriptan. Ergotamine is still widely used in some countries for the treatment of severe migraine attacks. It is generally regarded as a safe and useful drug if prescribed for infrequent use, in the correct dose, and in the absence of contraindications; however, safer and more effective options do exist in the triptans. In patients with status migrainous and patients with frequent headache recurrence, ergotamine is still probably useful.

Birth defects following maternal exposure to ergotamine, beta blockers, and caffeine

Ergotamine exposure during pregnancy has been suggested to cause birth defects which have a vascular disruptive aetiology. The present case provides additional support for the possible adverse fetal effects of exposure to ergotamine, caffeine, and propranolol during the first four months of pregnancy. At birth the infant showed evidence of early arrested cerebral maturation and paraplegia. The nature of these defects suggests a primary vascular disruptive aetiology. We hypothesise that ergotamine, acting either alone or in synergy with propranolol and caffeine, produced fetal vasoconstriction resulting in tissue ischaemia and subsequent malformation. This case raises the possibility that fetal malformation may result from concomitant use of multiple vasoconstrictive agents during pregnancy.

Crossover comparison of efficacy and preference for rizatriptan 10 mg versus ergotamine/caffeine in migraine

Rizatriptan is a selective 5-HT(1B/1D) receptor agonist with rapid oral absorption and early onset of action in the acute treatment of migraine. This randomized double- blind crossover outpatient study assessed the preference for 1 rizatriptan 10 mg tablet to 2 ergotamine 1 mg/caffeine 100 mg tablets in 439 patients treating a single migraine attack with each therapy. Of patients expressing a preference (89.1%), more than twice as many preferred rizatriptan to ergotamine/caffeine (69.9 vs. 30.1%, p < or = 0.001). Faster relief of headache was the most important reason for preference, cited by 67.3% of patients preferring rizatriptan and 54.2% of patients who preferred ergotamine/caffeine. The co-primary endpoint of being pain free at 2 h was also in favor of rizatriptan. Forty-nine percent of patients were pain free 2 h after rizatriptan, compared with 24.3% treated with ergotamine/caffeine (p < or = 0.001), rizatriptan being superior within 1 h of treatment. Headache relief at 2 h was 75.9% for rizatriptan and 47.3% for ergotamine/caffeine (p < or = 0.001), with rizatriptan being superior to ergotamine/caffeine within 30 min of dosing. Almost 36% of patients taking rizatriptan were pain free at 2 h and had no recurrence or need for additional medication within 24 h, compared to 20% of patients on ergotamine/caffeine (p < or = 0.001). Rizatriptan was also superior to ergotamine/caffeine in the proportions of patients with no nausea, vomiting, phonophobia or photophobia and for patients with normal function 2 h after drug intake (p < or = 0.001). More patients were (completely, very or somewhat) satisfied 2 h after treatment with rizatriptan (69.8%) than at 2 h after treatment with ergotamine/caffeine (38.6%, p < or = 0.001). Recurrence rates were 31.4% with rizatriptan and 15.3% with ergotamine/caffeine. Both active treatments were well tolerated. The most common adverse events (incidence > or = 5% in one group) after rizatriptan and ergotamine/caffeine, respectively, were dizziness (6.7 and 5.3%), nausea (4.2 and 8.5%) and somnolence (5.5 and 2.3%).

Subcutaneous sumatriptan in the treatment of headache during withdrawal from drug-induced headache

In a pilot study (5 patients) we investigated the effects of subcutaneous sumatriptan, a 5-HT1-like receptor agonist, on headache experienced during the withdrawal period of drug-induced headache. The pilot study indicated that the substance was effective mostly in patients who originally suffered from migraine. In a patient with tension headache the substance was less effective. In a second double-blind study on six migraine patients with severe drug-induced headache, the drug was highly effective in ameliorating headache and autonomic disturbances. Blood flow velocities measured in extracranial parts of internal and external carotid arteries by duplex-sonography and in middle cerebral and basilar arteries by transcranial Doppler showed no changes after administration of sumatriptan or placebo. This result suggests sumatriptan does not act primarily via constriction of the large cerebral arteries.

Clinical pharmacokinetics of ergotamine in migraine and cluster headache

Ergotamine has been in use for the treatment of migraine for a century and is still considered to be the most effective therapeutic agent for acute attacks. Only during the last few years have assays been developed, enabling its pharmacokinetics to be studied. Appropriate assays for determining ergotamine concentrations in plasma are radioimmunoassay and high-performance liquid chromatography. There is great interindividual variation in absorption of ergotamine in both patients and normal volunteers. Bioavailability is of the order of 5% or less by oral or rectal administration. After intramuscular or intravenous administration, plasma concentrations decay in a biexponential fashion. The elimination of half-life is 2 to 2.5 hours and clearance is about 0.68 L/h/kg. As yet, formal pharmacokinetics following oral dosing have not been determined. There is some evidence that ergotamine enters the cerebrospinal fluid. Metabolism occurs in the liver, and the primary route of excretion is biliary. Up to 90% of migraine patients experience complete or partial symptom relief after ergotamine, providing the drug is given as early in their attack as possible. Efficacy is greatest after parenteral administration, although adverse effects may make the rectal or inhaled routes preferable. There is some evidence to suggest that good responses are associated with plasma concentrations of 0.2 ng/ml or above within one hour of administration. The mode of action of ergotamine in migraine may be by means of selective arterial vasoconstriction on certain cranial vessel beds or, alternatively, by depression of central serotonergic neurons mediating pain transmission or circulatory regulation. Principal adverse effects of ergotamine include nausea, vomiting, weakness, muscle pains, paraesthesiae and coldness of the extremities. Ergotamine dependence is not uncommon, resulting in an exacerbation of the above symptoms. Dosage must therefore be limited to no more than 10mg per week to minimise toxicity.