Lack of effect of rheumatoid arthritis on clonixin metabolism

The effect of rheumatoid arthritis on the metabolism of the analgesic, 2-(3-chloro-o-toluidino) nicotinic acid (clonixin), was evaluated in 12 patients with rheumatoid arthritis and in 12 matched healthy control subjects. Males, age-matched by decades, had no renal, gastrointestinal, or hepatic disease, and took no drugs during the study. Lower (p less than 0.02) serum albumins and higher globulins in the patients (albumin: 3.87 plus or minus 0.18; globulin: 3.14 plus or minus 0.28 gm/100 ml) than in the control subjects (albumin: 4.42 plus or minus 0.10; globulin: 2.36 plus or minus 0.08 gm/100 ml) were considered to be manifestations of rheumatoid arthritis. Fasting subjects were given single oral doses of 750 mg of clonixin. A spectrophotometric method was used to determine drug blood levels. Serum half-life was 1.45 plus or minus 0.12 hr in patients and 1.50 plus or minus 0.13 hr in control subjects (p greater than 0.5). Mean peak concentration developed at 1.7 hr and was 40.0 plus or minus 2.6 mug/ml for patients and 46.1 plus or minus 3.1 mug/ml for control subjects. Thus a single oral dose of clonixin results in comparable blood levels in male patients suffering from rheumatoid arthritis and in healthy control subjects.