No significant effects of sodium aurothiomalate on haem metabolism and mixed function oxygenase activity in patients with rheumatoid arthritis

A.L. Herrick¹, R. Hodgkiss², P. Reed³, C. Weinkove³, M.I.V. Jayson¹, B. Houston²

¹University of Manchester Rheumatic Diseases Centre, Hope Hospital; ²University of Manchester Department of Pharmacy; ³University of Manchester Department of Clinical Biochemistry, Hope Hospital, Manchester, UK.

ABSTRACT
Objective
Animal studies suggest that gold compounds impair haem synthesis and increase haem degradation and, as a result, reduce activity of the hepatic haemoproteins cytochromes P-450. The aim of this study was to investigate whether intramuscular gold exerts similar effects in patients with rheumatoid arthritis (RA).

Methods
Urinary porphyrin and precursor excretion, erythrocyte protoporphyrin, and antipyrine clearance, were measured in 6 patients with RA before and 10 weeks after commencement of intramuscular gold.

Results
Parameters of haem metabolism were unaffected by gold. While antipyrine clearance was not statistically changed after gold treatment, in 3 of the patients there was an average decrease in antipyrine clearance of 23%.

Conclusion
Further studies examining RA patients at different time points are required to investigate further the possibility of reduced hepatic drug metabolising activity during prolonged treatment with gold.

Key words
Rheumatoid arthritis, gold, haem metabolism, cytochrome P-450, antipyrine clearance, hepatic drug metabolism.

Please address correspondence to: Dr. A.L. Herrick, University of Manchester Rheumatic Diseases Centre, Hope Hospital, Salford M6 8HD, UK. (Reprints will not be available).

Clin Exp Rheumatol 1999; 17: 461-462.
© Copyright Clinical and Experimental Rheumatology 1999.