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.