Experimental evaluation of the analgesic effect of ibuprofen on primary and secondary hyperalgesia

The analgesic effect of systemic ibuprofen was investigated with two human experimental pain models: (i) static mechanical stimulation of the inter digital web between the 2nd and 3rd finger and (ii) primary and secondary hyperalgesia induced by a 7-min burn injury on the calf. In each double-blind, randomized, two-way cross-over study 20 healthy male volunteers received either ibuprofen 600 mg or placebo tablets. Ibuprofen reduced pain evoked by static mechanical pressure in normal skin and by motor brush stimulation in the area of secondary hyperalgesia following burn injury. In contrast, ibuprofen did not reduce the area of secondary hyperalgesia to either pinprick or stroke following burn injury. Previous human experimental studies concerning the analgesic effect of NSAIDs are reviewed. Based on the previous literature and the present results we suggest that NSAIDs inhibit progressive tactile hypersensitivity but not the central sensitization itself.