Sumatriptan

Additional information

Sumatriptan is used to treat acute migraine attacks [1].Migraine is almost twice as common in women as in men [2, 3]. In a Swedish population- based study the one-year prevalence was 16.7 % in women and 9.5 % in men [4] which is slightly lower than three months prevalence reported from the US [2]. Another indication for (parenteral) triptans is cluster headache [5]. This is a trigeminal autonomic cephalgia with very painful, unilateral and short-lasting headache attacks. Cluster headache is rare with an estimated prevalence of 0.1%. In contrast to migraine, cluster headache is more common in men than in women [5]. The men-women ratio has recently been estimated to 2.5, older studies show a more pronounced male risk [6]. Smoking is a risk factor for cluster headache and the increased risk in women has been associated with more smoking in women [5, 6].

Pharmacokinetics and dosing

Direct comparisons of the pharmacokinetics in men and women with migraine have not been performed. However, in a comparison of data from different studies, young men without migraine had similar pharmacokinetic profile as young women with migraine [7]. According to the pharmaceutical company, no pharmacokinetic sex differences in AUC, Cmax, Tmax, and half-life of sumatriptan have been observed and no sex differentiation in dosing has been recommended [1].

Effects

A meta-analysis of four randomized, double-blind, placebo-controlled studies (329 men, 2066 women) analyzing efficacy and tolerability of sumatriptan, showed no sex differences in headache relief [8].

Results from the United States Cluster Headache Survey (816 men, 318 women) showed a sex difference in sumatriptan headache relief. In both men and women, the response to injectable sumatriptan was greater than the response to the nasal spray. Although 72% of women with cluster headache had a positive response to injectable sumatriptan, they were less likely to respond to sumatriptan (injectable or nasal spray) than men [9].

Adverse effects

Sumatriptan-induced chest pain was investigated in a Dutch post-marketing study (72 men, 294 women). Chest pain was more common in women than men (84% vs. 16%).  Hypertension and a family history of myocardial infarction increased the risk of sumatriptan-induced chest pain in men. Raynaud phenomenon was a significant risk factor in women but not in men  [10].

In the meta-analysis mentioned above [8], incidence of adverse events was similar between men and women. Also, the pharmaceutical company reports that the incidence of adverse events in controlled clinical trial was not affected by patient’s sex or age, despite drug formulation [1].

Reproductive health issues

Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).

Other information

Studies have found that sumatriptan increases plasma growth hormone in healthy men and women. Sumatriptan decreases plasma prolactin in healthy men, but not in women. This suggests that there are sex differences in the 5-HT regulation of prolactin release [11, 12].

Swedish population studies on dispensed triptans found a marked gender difference with a 3.6 times higher prevalence of triptan use in women [13, 14]. In contrast, over the counter use did not show any difference between men and women [14].