What Doctors Don't Tell YouSumatriptan is the latest wonder drug for treating the misery of migraine headache. It was launched by Glaxo under the brand name of Imigran.
As with most wonder drugs, sumatriptan is hugely expensive: £8 for one tablet, or £20 for one injection. Despite the cost, studies show that sumatriptan tablets don’t work in up to one third of patients, and up to one sixth of those being injected with it derive no benefit. Where an initial injection hasn’t worked, there is no evidence that a second shot will make any difference. Similarly, with tablet sumatriptan, studies suggest that a 100mg dose is the optimum amount, and that larger amounts don’t afford greater relief.Even with those helped by the drug, an alarmingly high proportion higher than that for those taking other anti migraine drugs suffer repeat attacks.
A Swedish migraine clinic reports that 53 per cent of patients “have had recurrences within five to 10 hours after almost every treated attack” (The Lancet, 10 October 1992). The same Swedish clinic reports that 70 per cent of those injected with sumatriptan suffered some side effects, most commonly neck pain/stiffness, tiredness, tightness or pressure across the chest , injection site reaction and tingling. The same range of side effects were reported in controlled trials of 4,859 patients published by Glaxo.
These controlled trials also show that oral (tablet) sumatriptan causes vomiting, taste disturbance, malaise, fatigue, dizziness and vertigo, drowsiness, and chest symptoms,.
Out of that catalogue of side effects, it is the chest symptoms which are causing most concern. Sumatriptan causes blood vessels in the brain to constrict and so theoretically helps stave off a migraine attack.There is growing concern that it has a similar constricting effect on circulation around the heart. The British Medical Journal (19 September 1992) reports two cases of serious abnormal heartbeat linked with sumatriptan. In one case, a 42 year old woman with no history of heart disease collapsed when her heart had stopped within three minutes of being injected with the drug.
Not surprisingly, the UK Committee on Safety in Medicine warns against the use of this drug in patients with coronary artery disease. It should also be avoided by those with angina and high blood pressure and “used cautiously” in patients with conditions that predispose them towards heart disease. (Drug and Therapeutics Bulletin, 26 October 1992). Children, elderly people, pregnant and lactating women should not take sumatriptan.
Our verdict: darkened rooms and ice packs preferred.
Maryon Stewart
Tom Ferguson MD
Daniel Redwood DC