Effect of long-term co-trimoxazole therapy on renal function.

In order to study the effect of long-term administration of co-trimoxazole on renal function, creatinine clearance rates were measured in 18 patients with neurogenic hypotonia of the bladder due to paraplegia, quadriplegia, hemiplegia and cerebrocervical injuries. The duration of the prophylactic treatment was between 60 and 80 days. The initial average creatinine clearance rate of this group was 99-0 ml/min and the final one was 110-7 ml/min (P = 0-15, n.s.). In addition, in seven cases the prophylaxis was extended to a period of 330 to 430 days. In this group the initial average creatinine clearance rate was 104-4 ml/min and the final one was 94-7 ml/min (P greater than 0-3, n.s.). It is concluded, therefore, that prolonged administration of co-trimoxazole to patients with creatinine clearance above 50 ml/min does not cause any marked deterioration in the renal function.