[Macrocytic animia due to the combination trimethoprim-sulfamethoxazole]

The authors report a case of macrocytic anemia due to folate deficiency occurring suddenly after the administration of trimethoprime-sulfamethoxazole and completely cured by folic acid. This type of complication occurs particularly often in patients who already have a relative folate deficiency. In our case only moderate alcoholism was found. Thus individual predisposition due to enzyme abnormality must be considered. Prophylactic administration of folic acid in patients receiving this drug association is thus advisable.