The glomerular filtration rate during penicillamine therapy in rheumatoid arthritis

Twenty-one consecutive patients (14 women and 7 men aged 35-68 years, mean age 50 years) with chronic active RNA for 2-24 years (mean 12.7 years) had a normal glomerular filtration rate (GFR) (mean value 99.8 +/- 14.8% (S.D.) of sex- and age-dependent normal value) before penicillamine treatment. All patients had previously been undergoing gold treatment; no patient had signs of renal disorder, or diabetes. GFR (total 51Cr-EDTA plasma clearance) was measured before and after 3 and 6 months' penicillamine treatment, respectively. Treatment was stopped because of side effects in 4 patients, including one with renal side effects. In the remaining 17 patients there was a mean fall in GFR of 3.8 +/- 12.5 (S.D.) ml/min during 6 months' penicillamine treatment, which was not significant. There was no correlation between individual changes in GFR and penicillamine dose. The individual changes in GFR correlated well to individual changes in plasma creatinine. Repeated determinations of plasma creatinine should be done during penicillamine treatment.