Indications for Trimethoprim:
Treatment of initial episodes of uncomplicated UTI due to susceptible strains (E. coli, P. mirabilis, K. pneumoniae, Enterobacter species, coagulase-negative Staphylococcus species, including S. saprophyticus).
Treat for 10 days. 100mg every 12 hours or 200mg every 24 hours. CrCl 15–30mL/min: 50mg every 12 hours. CrCl<15mL/min: not recommended.
Megaloblastic anemia due to folate deficiency.
May interfere with hematopoieses (esp. when given in large doses and/or prolonged periods). Obtain CBCs if signs of serious blood disorder develop, discontinue if significant reduction in any formed blood element is found. Possible folate deficiency. Renal or hepatic impairment. Pregnancy (Cat.C). Nursing mothers.
Folic acid inhibitor.
May potentiate phenytoin. May interfere with serum methotrexate assay, Jaffe alkaline picrate reaction assay for creatinine.
Rash, pruritus, GI upset, blood dyscrasias, hyperkalemia, hyponatremia, fever, increased BUN, serum creatinine; rare: aseptic meningitis, cholestatic jaundice, hypersensitivity reactions.