Diflunisal in the treatment of low back pain in a multicentre study.

An open trial with diflunisal (500 mg twice daily) in 766 outpatients consulting their doctor for low back pain, was carried out as part of the project "Back Pain 1981" in Finland. Of the patients (mean age 41 years), 460 had acute lumbago, 144 sciatica and 162 had chronic low back pain as a clinical diagnosis. In each diagnostic group there was a control group of patients receiving no drug therapy. Of the patients 65 percent were men and 35 percent women and the groups did not differ from this distribution in any diagnosis. The efficacy of the treatment was evaluated using four criteria: change of pain at rest and during exercise, patient's evaluation of the efficacy of the treatment, and the need for any supportive treatment. Side-effects of the drug therapy were registered. In all diagnostic groups the relief of pain both at rest and during exercise was greater in patients receiving diflunisal than in the controls. The greatest difference was found in lumbago. The patient's evaluation did not differ between the groups. The drug therapy diminished the need for supportive physical therapy. The frequency of side-effects was 8.6%. They led to the discontinuation of medication in 14 cases (3%). No severe side-effects were found. Diflunisal therapy for the relief of low back pain is therefore considered to be indicated in outpatient care.