Are There Any Interactions With Other Drugs And Therapies?
To date, studies have shown only one significant interaction related to using Propecia. No drug interactions of clinical importance have so far been identified. Specific testing for interactions have been conducted in human beings for drugs including digoxin, propranolol, theophylline, and warfarin. No significant interactions were detected for any of these drugs. General tests on a number of other common drugs have also revealed no significant interactions. Drugs that have been cleared as a result of this less thorough but generally reliable type of testing includes acetaminophen, alpha-blockers, analgesics, angiotensin-converting enzyme (ACE) inhibitors, anticonvulsants, benzodiazepines, beta blockers, calcium-channel blockers, cardiac nitrates, diuretics, prostaglandin synthetase inhibitors (NSAIDs), and quinolone anti-infectives.
The only significant Propecia-related interaction occurs in levels of a body chemical called prostate-specific antigen (PSA). PSA levels are known to decrease by about 50% for men using Propecia. The reduction in PSA levels is itself not very significant. What is significant is that PSA levels are often measured for diagnostic reasons in the case of men suspected of prostate cancer or other prostate problems. All patients taking Propecia should inform their doctors of this, but this is especially important for individuals with prostrate illness of any type. Doctors should take into consideration changes in PSA levels associated with taking Propecia.