Postmarketing experience with auranofin in the Federal Republic of Germany

Data about adverse events can be particularly useful when assessing newly marketed drugs. However, spontaneous reporting of adverse events does not generally provide sufficient or highly accurate data on incidence and prevalence. In order to provide the most complete and accurate data, a postmarketing surveillance program (PMSP) for auranofin (AF) oral gold therapy for rheumatoid arthritis (RA) was conducted in the Federal Republic of Germany (FRG) from December 1982 through December 1985. The objectives of the program were to observe a large population treated with AF for more than a year; to compare the safety profile of AF with experience from clinical trials; and to register rare or previously unknown adverse events. The program included 2,777 patients with RA from 928 test centers. Disease duration was less than 2 years in 29%. 2-5 in 23.2%, 5-10 in 32.5%, and more than 10 in 13.3% (no data for 2%); disease was mild or moderate in 67.4% and severe in 29.9% (no data for 2.7%). Auranofin was given 6 mg/day as either two 3-mg tablets at breakfast or 1 tablet at breakfast and 1 at the evening meal. Laboratory studies and efficacy, as indicated by increase in grip strength and decrease in number of tender and swollen joints, were monitored regularly. A total of 1,595 patients completed 1 year of treatment with AF. Withdrawals included 12.9% for adverse events, 4.2% for insufficient therapeutic effect, and 33.1% for a variety of administrative or technical reasons. The most common adverse event was alteration in stool pattern, which occurred in 22.5% of patients, compared with 46.6% in worldwide AF clinical trials. Other gastrointestinal symptoms occurred in 17.4%, compared with 22.4% worldwide. The occurrence of most adverse events in the PMSP was much less than in worldwide studies, for example: skin rash 7.3% vs. 24.2% worldwide, pruritus 4.2% vs. 16.6%, proteinuria 1.0% vs. 5.0%, and leukopenia 0.7% vs. 1.9%. These discrepancies may be explained by the method of monitoring employed in the postmarketing study, which favored the reporting of only clinically relevant adverse events. The pattern of occurrence of adverse events was similar to that seen during other AF trials, indicating that any intolerance to AF occurs primarily within the first 6 months of treatment. However, hematologic or nephrologic adverse events appear to be independent of time on therapy, with a constant monthly prevalence of about 0.1-0.2%.(ABSTRACT TRUNCATED AT 400 WORDS)