Onset of Action of Ibuprofen in the Treatment of Muscle‐Contraction Headache

SYNOPSIS A double‐blind, randomized, placebo‐controlled trial was conducted to determine the onset of action of ibuprofen 400 mg in the treatment of muscle‐contraction headache. Because this represents a non‐prescription dosage of this analgesic, we evaluated subjects with a history of recurrent muscle‐con‐traction headaches that were amenable to over‐the‐counter analgesic therapy. Headache pain intensity was evaluated on a visual analog scale, and pain relief was measured on a categorical scale 15, 30, 45, 60, 90, and 120 minutes after a single 400‐mg dose of ibuprofen or placebo. Efficacy was detected within 15 minutes on the pain intensity rating scale (P<0.05) and within 30 minutes and at all subsequent time points on both the pain intensity and pain relief rating scales (P<0.001). These results indicate an early onset of action of ibuprofen 400 mg in the treatment of muscle‐contraction headache.