Tamsulosin (Flomax - Boehringer Ingelheim), an alpha 1 - adrenoreceptor blocker, has been approved by the FDA for treatment of benign prostatic hyperplasia (BPH). It is claimed to bind preferentially to alpha1 receptors in the prostate.

Doxazosin (mesylate - Roerig), an alpha1-adrenergic receptor blocker similar to prazosin (Minipress, and others) and terazosin (Hytrin), was recently approved by the US Food and Drug Administration for treatment of hypertension.

Silodosin (Rapaflo - Watson Pharmaceuticals), an alpha1a-adrenoreceptor selective antagonist, has been approved by the FDA for treatment of benign prostatic hyperplasia (BPH). Some medications for BPH are listed in the table on page 4. Alpha1 blockers are commonly used with 5a-reductase inhibitors such as finasteride, which can shrink the size of the prostate, but may take months to do so.

The FDA has approved the use of the 5α-reductase inhibitor dutasteride (Avodart - GlaxoSmithKline) together with the alpha₁-blocker tamsulosin (Flomax - Boehringer Ingelheim) for treatment of benign prostatic hyperplasia (BPH). Use of an alpha1-blocker with a 5α-reductase inhibitor has been a common practice for years, but FDA approval of a particular combination permits the manufacturers to add an indication for it in both package inserts, recommend dosage for combination use, and advertise the benefits of using the 2 drugs together.

Finasteride (Proscar - Merck) has now been approved by the US Food and Drug Administration (FDA) for oral treatment of benign prostatic hyperplasia. A 4-aza-steroid, the drug is a specific inhibitor of steroid 5 -reductase, the enzyme that catalyzes conversion of testosterone to dihydrotestosterone. Dihydrotestosterone is required for development and maintenance of prostatic hypertrophy (JS Tenover, Endocrinol Metab Clin North Am, 20:893, 1991).

Sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra, Staxyn) have become the standard treatment for erectile dysfunction. Head-to-head comparisons of these agents are still lacking, but some differences between them and new recommendations for their dosing (see Table 2) are worth noting.

The phosphodiesterase type 5 (PDE5) inhibitor tadalafil (Cialis - Lilly) is now being promoted for once daily treatment of erectile dysfunction. Tadalafil differs from sildenafil (Viagra) and vardenafil (Levitra), the other PDE5 inhibitors marketed for erectile dysfunction in the US, in having a much longer duration of action.

Dutasteride (Avodart - GlaxoSmithKline) is now available in the US for oral treatment of benign prostatic hyperplasia (BPH). It is similar to finasteride (Proscar - Merck), which has been marketed for this indication since 1992 and also, since 1998, for alopecia (Propecia - Medical Letter 1998; 40:25).

Alfuzosin hydrochloride (Uroxatral - Sanofi-Synthelabo) is now available in the US in a new formulation for once-daily treatment of benign prostatic hyperplasia (BPH). The drug has been used in Europe since 1987. Alpha₁-blockers cause relaxation of smooth muscle tone in the bladder neck, prostatic capsule and prostatic urethra, relieving symptoms of urinary obstruction.

Tadalafil (Cialis - Lilly Icos) is the third oral drug to be approved by the FDA for treatment of erectile dysfunction. It has a longer duration of action than sildenafil (Viagra) or vardenafil (Levitra - Medical Letter 2003; 45:77).