Adults

0.4 mg orally once daily, approximately 30 minutes after the same meal each day. If no response after 2-4 weeks, the dose may be increased to 0.8 mg once daily.

Elderly

No dose adjustment is typically required in elderly patients, but caution is advised due to potential for orthostatic hypotension.

Renal_impairment

No dose adjustment is necessary in patients with mild to moderate renal impairment. Caution is advised in severe renal impairment (CrCl <10 mL/min).

Onset

Clinical effects may be noticeable within 4-8 hours; however, significant symptomatic improvement may take several days to weeks.

Excretion

Excreted primarily in the urine (76%) mainly as metabolites, with a small amount (9%) excreted in the feces.

Half life

The elimination half-life is approximately 9-15 hours in healthy volunteers and about 14-15 hours in benign prostatic hyperplasia patients.

Absorption

Tamsulosin is well absorbed from the gastrointestinal tract, especially when taken after a meal. Bioavailability is approximately 90% when taken with food.

Metabolism

Extensive metabolism in the liver, primarily via cytochrome P450 enzymes (CYP3A4 and CYP2D6).

0

Strong CYP3A4 inhibitors (e.g., Ketoconazole, Ritonavir): Increased tamsulosin exposure. Avoid concomitant use or use with caution.

1

Strong CYP2D6 inhibitors (e.g., Paroxetine): May increase tamsulosin exposure.

2

Other Alpha-1 blockers (e.g., Terazosin, Doxazosin): Increased risk of hypotension.

3

PDE5 inhibitors (e.g., Sildenafil, Tadalafil): Concomitant use may lead to additive hypotensive effects, especially orthostatic hypotension.