Towards a pragmatic human migraine model for drug testing: 2. Isosorbide-5-mononitrate in healthy individuals

BACKGROUND: A model for the testing of novel anti-migraine drugs should preferably use healthy volunteers for ease of recruiting. Isosorbide-5-mononitrate (5-ISMN) provokes headache in healthy volunteers with some migraine features such as pulsating pain quality and aggravation by physical activity. Therefore, this headache might respond to sumatriptan, a requirement for validation of any model. The hypothesis of the present study was that sumatriptan is effective in 5-ISMN-induced headache in healthy individuals.

METHODS: In a double-blind, randomised, crossover design, 30 healthy volunteers of both sexes received 5-ISMN 60 mg on two separate days, each day followed by oral self-administered placebo or sumatriptan 50 mg. Headache response and accompanying symptoms were registered in a questionnaire by the participants themselves.

RESULTS: 5-ISMN induced a reproducible headache in all 30 participants. The headache had several migraine-like features in all participants and 20 individuals developed a migraine-like attack. Median peak headache score was 5 on both experimental days (p = 1.00). There was no reduction, but instead an increase in headache intensity 2 hours after sumatriptan (p = 0.003). Difference in area under the headache score curve (AUC) 0-4 hours between sumatriptan and placebo was not significant (p = 0.30).

CONCLUSION: 5-ISMN is a very powerful inducer of migraine-like headache in healthy individuals but the headache does not respond to sumatriptan. The model is not useful for future drug testing.