The effect of D-penicillamine on plasma amino acids in rheumatoid arthritis.

The effect of D-penicillamine (DPA; 150 mg/day) on plasma amino acids administered to female patients suffering from rheumatoid arthritis (RA) was observed daily during the first 9 days of the treatment. A statistically significant influence of the oral DPA administration was detected. In comparison to control, a decrease in 12 out of 18 amino acids was found on day 2. Furthermore, for 6 amino acids an increase and a peak concentration on day 6 or 7 were observed. Surprisingly, similar results were also obtained in rats after oral application of DPA. These findings give further evidence for the multifactorial action of DPA.