Use with caution in patients with hepatic disease. Use with caution in patients in whom cell production in bone marrow is depressed. Patients should be counseled to report any symptoms of agranulocytosis such as fever, sore throat, unusual bleeding or bruising or skin rash. Propylthiouracil may indirectly increase the concentrations of theophylline by correcting the hyperthyroid state.
Propylthiouracil can increase or decrease the effects of warfarin.