HOW MUCH SUMATRIPTAN IS TOO MUCH?
All triptans are contraindicated in patients with coronary artery disease. Many physicians are unaware of the risk of myocardial infarction with use of triptans in this patient group. In the absence of significant risk factors, this risk is extraordinarily rare. GSK has reportedly sold at least 1 billion Imitrex brand tablets. In a review of sumatriptan postmarketing experience, the authors identified 451 serious cardiac effects out of 236 million migraine attacks and more than 9 million patient exposures over 6 years. In most, though apparently not all, risk factors for coronary artery disease were present.
Upon this background comes a report of 53 patients with chronic cluster headaches who had daily attacks and used 2 or more 6 mg sumatriptan injections per day for at least 2 years. About 40% possibly developed some “tolerance” but still believed that this was their best option.
The highest manufacturer’s recommended daily dose is 2 injections of 6 mg each per 24 hours. Most cluster headache patients need more.
In that 2-year study, no patients needed to stop medication nor were there any serious adverse effects, and no EKG abnormalities were found.
For years, headache specialists have been allowing cluster headaches to use multiple doses of injectable sumatriptan a day, and this study gives some comfort to support that approach.
See Neurology, January 12, 2016, lead author Leone.