Sulfamethoxazole

Sulfamethoxazole crosses the placenta and its safety in pregnant women has not been established. Case-control studies have shown that there may be an association between exposure to folate antagonists and birth defects in humans.

It has been shown to cause foetal abnormalities.

Sulfamethoxazole competes with bilirubin for binding to plasma albumin.

Sulfamethoxazole is excreted in breast milk. Administration of sulfamethoxazole should be avoided in late pregnancy and in lactating mothers where the mother or infant has, or is at particular risk of developing, hyperbilirubinaemia. Additionally, administration of sulfamethoxazole should be avoided in infants younger than eight weeks in view of the predisposition of young infants to hyperbilirubinaemia.

There have been no studies to investigate the effect of sulfamethoxazole on driving performance or the ability to operate machinery. Further a detrimental effect on such activities cannot be predicted from the pharmacology of the drug. Nevertheless the clinical status of the patient and the adverse events profile of sulfamethoxazole should be borne in mind when considering the patients ability to operate machinery.