Objective: To quantify the efficacy and safety of naproxen, ibuprofen, mefenamic acid, aspirin and acetaminophen (paracetamol) in the treatment of primary dysmenorrhoea through a systemic overview of randomised controlled trials.
Methods: MEDLINE, EMBASE and the Science Citation Index were searched for randomised controlled trials. Efficacy was assessed by measurement of pain relief, requirement for rescue analgesics, restriction of daily life and absence from work or school. The rate ratios of side effects were used to assess safety.
Results: Fifty-six trials describing 55 comparisons of analgesics with placebo and 12 direct comparisons with other analgesics met our inclusion criteria. Women taking naproxen were over three times more likely to have at least moderate pain relief than those taking placebo. Ibuprofen, mefenamic acid and aspirin were also superior to placebo but acetaminophen was not. The requirement for rescue analgesics, restriction of daily life and absence from work or school were less frequent with naproxen and ibuprofen than placebo but not with aspirin or acetaminophen. Direct comparisons did not show any difference between naproxen and ibuprofen. Side effects occurred more frequently only with naproxen when compared with placebo.
Conclusion: Naproxen, ibuprofen, mefenamic acid and aspirin are all effective in primary dysmenorrhoea. Ibuprofen appears to have the most favourable risk-benefit ratio. Acetaminophen appears to be less effective than nonsteroidal anti-inflammatory drugs, but there was only one trial meeting our inclusion criteria and further studies are required.