finasteride (cont.)

Pharmacy Author:
Medical and Pharmacy Editor:

DRUG INTERACTIONS: Carbamazepine, rifampin, and St. John's wort may reduce blood levels of finasteride by increasing its breakdown in the liver. Itraconazole, erythromycin and similar drugs increase blood levels of finasteride. 

PREGNANCY: Finasteride should not be used or handled by pregnant females. Finasteride prevents the conversion of testosterone to DHT, a hormone which is necessary for the development of male genitalia. Finasteride should not be used or handled by pregnant mothers due to the potential hazard to the male fetus.

NURSING MOTHERS: Finasteride should not be used by women. It is not known if finasteride is excreted in human milk.

SIDE EFFECTS: The most common side effects associated with finasteride are breast enlargement, decreased libido, erectile dysfunction, and ejaculation disorders. Serious side effects include increased risk of high-grade prostate cancer, and increased risk for male breast cancer.

REFERENCE: FDA Prescribing Information


Medically Reviewed by a Doctor on 10/9/2014


Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Pill Finder Tool

Need help identifying pills and medications?
Use the pill identifier tool on RxList.


Back to Medications Index