Zolmitriptan

Additional information

Zolmitriptan 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

There are small pharmacokinetic studies of zolmitriptan showing varying results, none which were adjudicated to be of clinical importance [7, 8]. Other studies found differences in pharmacokinetics only between young men and women (18-39 years) but not in the elderly (65-75 years) [9, 10]. Although some sex differences in zolmitriptan pharmacokinetics have been reported in young adults [7-10], no dosage adjustment based on patient’s sex is recommended. [11].

Effects

Headache relief after administration of zolmitriptan has been evaluated in open-label clinical trials. Two-hour headache response rates to an initial dose of 2.5 mg or 5 mg zolmitriptan were 85% and 79-81%, respectively. Responses were unaffected by patient’s sex [12, 13]. Also, the pharmaceutical company reports that the efficacy of zolmitriptan was similar in men and women, for both drug formulations [1].

Results from randomized, double-blind studies of migraineurs (66 men, 280 women) show no sex differences in response to frovatriptan 2.5 mg, rizatriptan 10 mg, zolmitriptan 2.5 mg or almotriptan 12.5 mg [14].

Adverse effects

Tolerability of zolmitriptan was evaluated in an international, open-label study (288 men, 1769 women). The types of adverse events observed were similar in men and women, although the incidence of adverse events was slightly higher in women (78%) than men (61%) [13].

A placebo-controlled clinical trial (1540 men, 1210 women) reported that the nature and type of adverse events were similar in men and women, although the frequency of reported adverse events was higher in women (48%) than men (30%). This sex difference was also observed in patients who received placebo and may reflect a difference between men and women in adverse event reporting. The frequency of serious adverse events did not differ between men and women [15]. Contrary to this, the pharmaceutical company reports that there were no sex differences in incidence of adverse events in controlled clinical trials [1].

Reproductive health issues

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

Other information

Swedish population studies on dispensed triptans found a marked gender difference with a 3.6 times higher prevalence of triptan use in women [16, 17]. In contrast, over the counter use did not show any difference between men and women [17].