Hospitalization for serious blood and skin disorders following use of co-trimoxazole.

AIMS The objective of this study was to quantify the risk of serious blood and skin disorders associated with co-trimoxazole. METHODS We conducted a population-based cohort study of serious blood and skin disorders requiring hospitalization among otherwise healthy users of co-trimoxazole at Group Health Cooperative and Puget Sound (GHC). RESULTS During the years 1987 to 1993 we found six cases of co-trimoxazole-associated blood disorders and three cases of co-trimoxazole-associated skin disorders yielding risks of 5.6/100,000 (95% CI 2.6-12.2) and 2.8/100,000 (95% CI 0.9-8.2) respectively. In all cases found there was prompt recovery after discontinuation of co-trimoxazole. We found no cases of toxic epidermal necrolysis. CONCLUSIONS We conclude that the risk of blood and skin disorders associated with the use of co-trimoxazole leading to hospitalization is low.