Is acetaminophen, and its combination with pamabrom, an effective therapeutic option in primary dysmenorrhoea?

Primary dysmenorrhoea is the most frequent gynaecological condition, with a prevalence of 40 - 90% in women within the reproductive age. It is characterised by cyclic pelvic pain related to menstrual period, vomiting and headache. As prostaglandins and leukotrienes appear to be a major causative factor in this condition, NSAIDs are the first choice for treatment. Acetaminophen is an over-the-counter analgesic/antipyretic agent widely used in primary dysmenorrhoea as monotherapy or in combination. It has a weak inhibitory action on peripheral prostaglandin synthesis. Acetaminophen displays good gastrointestinal tolerance without any effect on haemostasis. Its combination with pamabrom, a mild diuretic agent, (Women s Tylenol Menstrual Relief Caplets, Midol Teen) was approved by the FDA for use in this indication. Nevertheless, the available information concerning the efficacy of acetaminophen in primary dysmenorrhoea is limited and not conclusive with respect to other NSAIDs or even placebo. The clinical evidence regarding the association with pamabrom is even more scarce. Well-designed, randomised, controlled trials are required to demonstrate the efficacy of the combination of acetaminophen plus pamabrom in the treatment of primary dysmenorrhoea.