PEARLS No. 236 March 2010, written by Brian R McAvoy

Clinical question

How effective are non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of primary dysmenorrhoea?

Bottom line
Compared with placebo, NSAIDs are a highly effective treatment for dysmenorrhoea, though women using them need to be aware of the significant overall risk that they may cause adverse effects, such as indigestion, headaches or drowsiness. There is insufficient evidence to indicate whether any individual NSAID is more effective or safer than others. It appears NSAIDs are more effective than paracetamol, though there were only 3 relevant studies. Nineteen different types of cox-1 NSAIDs were evaluated in the included studies.

Caveat
The included studies used a wide variety of continuous pain scales as their primary or sole measure of effectiveness. The measurement and reporting of adverse effects was generally poor. At least half the studies were co-authored or financially supported by pharmaceutical company associates and it was unclear how most of the other studies were funded.

Context
Dysmenorrhoea is a common gynaecological problem, consisting of painful cramps accompanying menstruation, which in the absence of any underlying abnormality is known as primary dysmenorrhoea. Research has shown women with dysmenorrhoea have high levels of prostaglandins, hormones known to cause cramping abdominal pain. NSAIDs are drugs which act by blocking prostaglandin production.  

Cochrane Systematic Review
Marjoribanks J et al. Non-steroidal anti-inflammatory drugs for dysmenorrhoea. Cochrane Reviews 2010, Issue 1. Article No. CD001751. DOI: 10.1002/14651858.CD001751.pub2. This review contains 73 studies involving 5156 participants.