Boureau F, Schneid H, Zeghari N et al.
Annals of the Rheumatic Diseases, 2004;63:1028-1034.

The Ibuprofen, Paracetamol Study in Osteoarthritis (IPSO) study was a double-blind, randomized, multi-centre study comparing the analgesic efficacy of single and multiple doses of ibuprofen with that of paracetamol in patients with knee or hip osteoarthritis. Two hundred and twenty-two patients were randomized: 156 had a painful knee joint and 66 a painful hip joint. The main efficacy criterion was pain intensity assessment after a single dose (ibuprofen 400 mg, paracetamol 1,000 mg). Functional disability assessment and patient global assessment were carried out over 14 days.

The IPSO study shows that for the treatment of osteoarthritic pain, ibuprofen 400 mg at a single and multiple dose (1,200 mg/day) for 14 days is more effective than paracetamol, either as a single dose of 1,000 mg or a multiple dose (3,000 mg/day). Because ibuprofen and paracetamol have similar tolerability, this study indicates that the efficacy/tolerability ratio of ibuprofen is better than that of paracetamol in this indication over 14 days.