Comparing risk estimates of sulphonamide-induced agranulocytosis from the Swedish Drug Monitoring System and a case-control study.
A comparison has been made of risk estimates for agranulocytosis connected with sulphasalazine and trimethoprim-sulphamethoxazole (T-SM) therapy calculated from data in the Swedish Drug Monitoring System ("spontaneous" reports, sales and prescription information) and a population based case-control study (the IAAAS). The relative risk for agranulocytosis during sulphasalazine treatment was calculated to be 107 and 123 by the spontaneous reporting system and the case-control study, respectively. The corresponding excess risk in both systems was 1.8. For T-SM the relative risk was 17 in the spontaneous reporting system and 12 in the case-control study, while the excess risk calculated for 3 days of treatment was 0.9 in the spontaneous reporting system, and 1.6 for 3 or more days of treatment in the case-control study. It is concluded that the Swedish Drug Monitoring System gives an appropriate estimate of the risk of developing agranulocytosis in association with the two drugs studied.
Keisu
M
M
Section of Pharmacoepidemiology, Medical Products Agency, Uppsala, Sweden.
Ekman
E
E
Wiholm
B E
BE
D000293:Adolescent; D000328:Adult; D000368:Aged; D000380:Agranulocytosis / Q000139:chemically induced* / Q000503:physiopathology; D016022:Case-Control Studies; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D012460:Sulfasalazine / Q000009:adverse effects*; D013548:Sweden; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects*
D012460:Sulfasalazine; D015662:Trimethoprim, Sulfamethoxazole Drug Combination