Adults

0.4 mg once daily, administered approximately 30 minutes after the same meal each day. The dose may be increased to 0.8 mg once daily if needed, after 2-4 weeks.

Elderly

No dosage adjustment is required for elderly patients.

Renal_impairment

No dosage adjustment is typically required for mild to moderate renal impairment. Caution is advised in patients with severe renal impairment (creatinine clearance <10 mL/min).

Onset

Symptomatic improvement may be observed within 2-4 weeks of starting treatment.

Excretion

Excretion occurs mainly via the kidneys (approximately 76%) as metabolites and unconjugated active compounds. A smaller amount is excreted in feces.

Half life

The elimination half-life from plasma is approximately 9-15 hours. At steady state, the apparent half-life is approximately 14-19 hours.

Absorption

Tamsulosin is rapidly and almost completely absorbed from the gastrointestinal tract (bioavailability approx. 90%). Peak plasma concentrations (Cmax) are reached approximately 4-5 hours after oral administration under fed conditions. Food reduces the rate but not the extent of absorption.

Metabolism

Tamsulosin is extensively metabolized in the liver, primarily by cytochrome P450 enzymes, CYP3A4 and CYP2D6. Less than 10% of the dose is excreted as unchanged drug.

Other alpha-blockers

Concomitant use with other alpha-adrenergic blocking agents may lead to hypotensive effects.

CYP3A4 and CYP2D6 inhibitors

Concomitant administration with strong CYP3A4 inhibitors (e.g., ketoconazole) or moderate CYP3A4 inhibitors with CYP2D6 inhibitors (e.g., paroxetine) may significantly increase Tamsulosin exposure. Use with caution.

PDE5 inhibitors (e.g., sildenafil, tadalafil)

Concomitant administration may lead to additive blood pressure lowering effects, resulting in symptomatic hypotension. Use with caution and consider starting PDE5 inhibitor at the lowest dose.