Current issues of ACP Journal Club are published in Annals of Internal Medicine


Low-dose aspirin reduced the recurrence of migraine

ACP J Club. 1991 Jan-Feb;114:10. doi:10.7326/ACPJC-1991-114-1-010

Source Citation

Buring JE, Peto R, Hennekens CH. Low-dose aspirin for migraine prophylaxis. JAMA. 1990;264:1711-3. [PubMed ID: 220473]



To determine whether low-dose aspirin therapy reduced self-reported migraine.


Randomized, double-blind, placebo-controlled trial of 60 months duration.


The U.S. male medical arena.


22 071 U.S. male physicians, 40 to 84 years of age, who volunteered for and were enrolled in the Physicians' Health Study.


Subjects were randomly assigned, using a 2 × 2 factorial design, to 1 of 4 regimens: aspirin, 325 mg every other day, β-carotene, both active agents, or both placebos.

Main outcome measures

Every 6 months for the first year, and annually thereafter, participants were sent brief questionnaires about the occurrence of several medical conditions. Although the primary purposes of the parent trial were to determine the abilities of aspirin to reduce vascular events and β-carotene to reduce cancer, the questionnaire included specific items on whether participants had experienced either migraine or headache since the return of the last questionnaire. No information on migraine or headache was obtained at the start of the study, and no information was obtained during the study on the frequency or severity of migraine attacks.

Main results

β-carotene had no effect on self-reported migraine. 818 of 11 034 (7%) of those allocated to placebo, however, and 661 of 11 037 (6%) of those allocated to aspirin reported migraine at some time after randomization (P < 0.001). {This absolute risk reduction of 1% means that 70 patients would need to be treated with aspirin (compared with placebo) to prevent 1 additional migraine, 95% CI 48 to 131; the relative risk reduction was 19%, CI 11% to 27%}.* Benefit extended to all subgroups, appeared in the first 6 months of treatment, persisted, and did not appear to be caused by simple analgesia (nonmigraine headaches were reported with equal frequency among those allocated to aspirin and placebo). A telephone survey of a random sample of those reporting migraines confirmed that first attacks had occurred well before the trial began, indicating that aspirin prevents the recurrence rather than the development of migraines. At 60 months, morbidity follow-up was 99.7% complete; the reported consumption of aspirin or other platelet-active drugs was 86% in the aspirin group and 14% in the placebo group. Gastrointestinal discomfort attributable to aspirin was 0.5%.


Low-dose aspirin (325 mg every other day) reduced the recurrence of migraine.

Source of funding: The National Institutes of Health.

Address for article reprint: Dr. J.E. Buring, 55 Pond Avenue, Brookline, MA 02146, USA. Dr. R. Peto, 65 Banbury Road, Oxford, England, UK.

*Numbers calculated from data in article.


Drugs that are currently used for prophylaxis against frequent migraine headaches are associated with a broad spectrum of side effects. The large study reported by Buring and colleagues indicates that the use of low-dose aspirin, with its low incidence of side effects, may reduce the recurrence of migraines. Some methodologic problems, however, make the study results only suggestive. Objective outcome criteria are missing for the diagnosis of migraine. No baseline data are given on type, frequency, and severity of migraines in the aspirin and placebo groups, so it is not possible to be sure whether the recurrence rate difference for the two groups is caused only by aspirin.

Even though this study has some shortcomings, practitioners may consider using low-dose aspirin for first-line migraine prophylaxis because the risk for side effects is low. Also, aspirin reduces platelet hyperaggregability that could be relevant to the occasional occurrence of migrainous infarction (1).

Barbara Scherokman, MD
Uniformed Services University of Health SciencesBethesda, Maryland, USA


1. Kalendovsky Z, Austin J, Steele P. Increased platelet aggregability in young patients with stroke. Arch Neurol. 1975;32:13-20.