Drug interactions in arthritic patients.

The drug treatment of 100 consecutive new patients admitted to a regional rheumatology centre was reviewed. Potential drug interactions actions were sought according to appendix one of the British National Formulary (September 1989) and identified in 55 of 100 patients. The clinical and laboratory features of these patients were then reviewed, showing that only 11 displayed clinical manifestations of a drug interaction. Five patients had drug induced drowsiness, which was easily corrected, five a raised serum creatinine, which was less easily corrected, and one both. Although there is considerable potential for drug interaction in patients with severe arthritis, the proportion of patients who display clinical manifestations of this is small.