Sydnes O A, Brath H K, Haerum L B, Straume S
Rheumatol Rehabil. 1976;Suppl:43-4. doi: 10.1093/rheumatology/15.5.43.
In a double-blind cross-over trial in rheumatoid arthritis, no difference was found between ketoprofen and phenylbutazone with regard to clinical efficacy at the dosages used. There was a higher incidence of side-effects reported during treatment with phenylbutazone.