Drug General Information (ID: DDIA0967RM)
Drug Name			Propylthiouracil		Drug Info		Digitoxin		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antithyroid Agents				Antiarrhythmic Agents
Structure

Mechanism of Propylthiouracil-Digitoxin Interaction (Severity Level: Moderate)
Decreased renal excretion (Unspecific) Click to Show/Hide Mechanism Graph
Drug Name		Propylthiouracil				Digitoxin
Mechanism		Reduce excretion of digitalis glycosides				Digitalis glycosides
Key Mechanism Factor 1
		Factor Name		Pharmacokinetics
		Factor Description		Alters the excretion of the drug, resulting in changes in the plasma concentration of the drug and affecting the pharmacological effects.
Mechanism Description		Decreased renal excretion of Digitoxin caused by Propylthiouracil

Recommended Action
Management		Monitor the patient closely for altered efficacy and safety while achieving a euthyroid state or when antithyroid agents are added, discontinued, or dosing changes are made. Digitalis dose reductions may be required.

References
1	Product Information. Tapazole (methimazole). King Pharmaceuticals Inc, Bristol, TN.
2	Product Information. Propylthiouracil (propylthiouracil). Lederle Laboratories, Wayne, NJ.
3	Doherty JE, Perkins WH "Digoxin metabolism in hypo- and hyperthyroidism. Studies with tritiated digoxin in thyroid disease." Ann Intern Med 64 (1966): 489-507