Finasteride
Indications
Finasteride is used for:
Male pattern baldness, Benign prostatic hyperplasia
Adult Dose
Oral
Benign prostatic hyperplasia
Adult: 5 mg once daily for at least 6 mth.
Male pattern baldness
Adult: 1 mg once daily for at least 3 mth.
Hepatic impairment: Caution in liver dysfunction; monitor
Child Dose
Renal Dose
Renal impairment: Dose adjustment not necessary
Administration
May be taken with or without food.
Contra Indications
Children, exposure of pregnant women to finasteride either via direct contact with crushed tab or through semen of male sexual partners who are taking finasteride; pregnancy, lactation.
Precautions
Undiagnosed prostate cancer, liver dysfunction, obstructive uropathy.
Lactation: Excretion in milk unknown; contraindicated
Pregnancy-Lactation
Pregnancy category: X
Lactation: Excretion in milk unknown; contraindicated
Interactions
No drug interactions of clinical importance have been identified. Finasteride does not appear to affect significantly the cytochrome P-450-linked drug metabolizing enzyme system. Compounds which have been tested in man have included propranolol, digoxin, glyburide, warfarin, theophylline and antipyrine, and no clinically meaningful interactions were found.
Other Concomitant Therapy: Although specific interaction studies were not performed, in clinical studies Finasteride was used concomitantly with angiotensin converting-enzyme (ACE) inhibitors, acetaminophen, acetylsalicylic acid, alpha-blockers, beta-blockers, calcium-channel blockers, cardiac nitrates, diuretics, H2-antagonists, HMG-CoA reductase inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), quinolones and benzodiazepines without evidence of clinically significant adverse interactions.
Adverse Effects
Side effects of Finasteride :
1-10%
Erectile dysfunction (1.3-8.1%), Decrease libido (1.8-6.4%), Breast enlargement (0.5-1.8%), Ejaculation disorder (0.8-1.2%)
<1%
Breast tenderness (0.4-0.7%), Rash (0.5%)
Mechanism of Action
Finasteride is a competitive inhibitor of the enzyme 5-alpha reductase which converts testosterone to dihydrotestosterone (DHT), thus resulting in decreased serum levels of DHT.