Dipyridamole and headache--a pilot study of initial dose titration

Headache is reported by about one third of patients using dipyridamole (DP) after stroke or TIA. No study has systematically examined if initial dipyridamole titration may affect this headache. We therefore randomised patients to (1) standard aspirin and dipyridamole treatment b.i.d. for 2 weeks or (2) titration with aspirin only in the morning and aspirin and dipyridamole in the evening for 5 days, followed by 9 days of standard aspirin and dipyridamole treatment. Among 57 patients included for analysis, moderate to severe headache was reported by 28% in the standard treatment group and 25% in the titration group (n.s.). Headache for more than two consecutive days occurred in 24% and 11%, respectively. Rescue medication because of headache for more than 2 days was used by 14% and 0% in the respective groups. The cumulative number of days with headache was more than twice as high in the standard treatment group. The total numbers of other side effects were 25 and 11 in the two groups. The observed differences in this pilot study were not statistically significant, but nevertheless suggest that titration with an initially lower dose of dipyridamole may be considered to reduce headache and thereby increase compliance. A larger study is needed to clarify this with sufficient statistical power.