Finasteride Doxazosin

McConnell JD, Roehrborn CG, Bautista OM et al. The long term effect of doxazosin, finasteride, and combination therapy on the clinical progression of benign prostatic hyperplasia. N Engl 1 Med 2003 349 2387-2398. 

Prazosin (Minipress) Alfuzosin (Uroxatral) Terazosin (Hytrin) Doxazosin (Cardura) Tamsulosin (Flomax) Finasteride (Proscar) Dutasteride (Avodart) Bicalutamide (Casodex) Flutamide (Eulexin) Leuprolide (Lupron) Nafarelin (Synarel) Megestrol acetate... 

Finasteride can be administered alone or in combination with the alpha-blocker doxazosin. 

Geriatric Considerations - Summary Alpha-adrenergic blockers are modestly effective alone, and in combination with 5-alpha reductase inhibitors (e,g, finasteride) in the treatment of urinary obstructive symptoms related to benign prostatic hyperplasia. Alfuzosin is a "uroselective" alpha-blockerwhich appears to cause less orthostatic hypotension than nonselective alpha-blockers such as terazosin, prazosin, and doxazosin. 

Striking evidence of the association of finasteride with male breast cancer comes from the Medical Therapy of Prostatic Symptoms (MTOPS) study, a National Institutes of Health (NIH)-sponsored study of about 3047 men that compared finasteride, doxazosin, and the combination for the treatment of benign prostatic hyperplasia. The rate of breast cancer in this trial for men taking finasteride either alone or with doxazosin was four in 1554, or nearly 200 times that of the general population one man in the finasteride + doxazosin group and three in the finasteride-alone group developed male breast cancer (74). 

Kirby R, Roehrborn CG, Boyle P, et al. Efficacy and tolerability of doxazosin and finasteride, alone or in combination, in treatment of symptomatic benign prostatic hyperplasia the Prospective European Doxazosin and Combination Therapy (PREDICT) trial. Urology 2003 61 119-126. 

No clinically important interaction has been found to occur between finasteride and doxazosin. In one study terazosin did not interact with finasteride, but in another there was a suggestion of modestly increased finasteride levels. No clinically significant interaction appears to occur between dutasteride and tamsuiosin or terazosin. 

Vashi V, Chung M, Hilbert J, Lawrence V, Phillips K. Pharmacokinetic interaction between finasteride and terazosin, but not finasteride and doxazosin. J Clin Pharmacol (1998) 38, 1072-6. 

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