[The value of serum salicylate determination in patients with rheumatoid arthritis (author's transl)].

Thirty-one patients with rheumatoid arthritis in the Veterans General Hospital from July 1978 to June 1979 were treated with acetylsalicylic acid. The serum salicylate level was determined twice a week. The dose of acetylsalicylic acid was adjusted to keep the serum salicylate level around 15-30 mg%. All patients were started with an initial dose of 65 mg/kg/day. The serum salicylate levels at the 4th day varied greatly from 5.6 to 29.5 mg%. Tinnitus was noted in 24 patients. It occurred when the serum salicylate level reached 28.41 +/- 1.84 mg%. Abnormal liver function was noted in 19.35% (6/31) patients during treatment. It returned to normal after withdrawal of acetylsalicylic acid in 3 cases, after decrease of the dosage in 2 cases and on the same dosage in 1 case. Patients with positive FANA and RF were more prone to develop abnormal liver function during treatment. Monitoring of serum salicylate level may decrease the incidence of hepatic toxicity and maintain the dosage of acetylsalicylic acid in optimal range.