Hepatic or renal impairment. AIDS (increased risk of toxicities). Folate or G6PD deficiency. Severe allergy or bronchial asthma. Circulatory shock. Malnutrition. Porphyria or thyroid dysfunction.

Trimethoprim-sulfamethoxazole (TMP-SMX, Bactrim®), initially used for prophylaxis of urinary tract infections, was later proven to be of value for the prevention of opportunistic infections ...