INFECTION-RATE AND USE OF ANTIBIOTICS IN PATIENTS WITH RHEUMATOID-ARTHRITIS TREATED WITH METHOTREXATE

Objective-To investigate prospectively the frequency and type of infec tions and the use of antibiotics among patients with rheumatoid arthri tis (RA) on methotrexate (MTX) and patients with RA without MTX. Metho ds-Every three months for one year 77 patients on MTX and 151 patients without MTX were asked about infections and the use of antibiotics by means of a standardised questionnaire. Medication was checked with th e pharmacist. Results-In the MTX group there were significantly more i nfections and more antibiotic therapy. The relative risks for patients on MTX of infection or antibiotics use were 1.52 (95% Confidence Inte rval (CI) 1.04-2.22) and 1.49 (95% CI 1.04-2.13), respectively. The re lative risk of MTX for respiratory tract infections was 1.43 (95% CI 0 .96-2.14) and for skin infections 2.19 (95% CI 1.45-3.31). The risks c ould only partly be by differences in disease severity and were not re lated to either duration of MTX therapy or use of prednisone. Three pa tients in the MTX group had herpes tester versus one in the control gr oup. Conclusions-Treatment with MTX increases the rate of infection an d thus the use of antibiotics but does not lead to serious complicatio ns necessitating discontinuation of the drug.