These were the findings of a Cochrane Systematic Review using data from 13 studies with 4,222 participants.

Migraine affects about 18% women and 6% of men in western populations, mostly affecting people 30 to 50 years old. The common symptom, whatever type of migraine someone has, is a severe headache, typically once or twice a month, lasting between four and 72 hours.

The headache is often pounding, on one side of the head, frequently with nausea, and sometimes with vomiting. Given the numbers of people affected, and the extent of the pain caused, migraine has considerable social and economic impact.

What sufferers want is for the pain to go away completely and quickly, and not return -- though for many the headache does return within 24 hours of the first attack. Despite being common and debilitating, many sufferers choose to use only medicines available without prescription from pharmacies (over the counter, OTC medicines), or use OTC medicines to supplement prescription medicines, but good reviews of the evidence have been lacking. In the review published this week, Cochrane Researchers compared the differences in response rates for people taking aspirin alone or aspirin plus an antiemetic with those of people taking placebo or another active agent.

Researchers found that severe or moderate migraine headache pain can be reduced from moderate or severe to no pain in 25% of people (one in four) within two hours by taking a single dose of 900-1000 mg aspirin alone compared to placebo, with pain reduced to no worse than mild pain in 52% (one in two). While aspirin alone reduced some of the associated symptoms of nausea, vomiting, photophobia and phonophobia, aspirin plus metoclopramide was particularly good a reducing nausea and vomiting, though it produced no greater frequency of pain relief.

Researchers also found that a combination of aspirin and metoclopramide had a similar effect to 50 mg of the headache treatment sumatriptan (a serotonin agonist), but that a 100 mg dose of sumatriptan was slightly better at delivering a pain free response within two hours of taking the medication.

In terms of adverse effects, short-term use of the different drugs produced mostly mild and transient adverse effects. These occurred more commonly when taking aspirin than when taking a placebo, and more commonly when taking 100 mg sumatriptan than when taking aspirin plus metoclopramide.

"Aspirin plus metoclopramide will be a reasonable therapy for acute migraine attacks, but for many it will be insufficiently effective," said the study leader Andrew Moore, who works in Pain Relief and the Department of Anaesthetics at the John Radcliffe Hospital, Oxford, UK.

"We are presently working on reviews of other OTC medicines for migraines, to provide consumers with the best available evidence on treatments that don't need a prescription."

Note: If no author is given, the source is cited instead.

• Headache Research
• Pain Control
• Fibromyalgia

• Headaches
• Stroke
• Disorders and Syndromes

• Tension headache
• Cluster headache
• Migraine
• Headache
• Analgesic
• COX-2 inhibitor