Tamsulosin

Alpha-adrenergic blockers for prostatic disorders

ATC code: G04CA02 (Tamsulosin)

Mechanism of action

Selective alpha-1A adrenergic receptor antagonist. Relaxes smooth muscle in the prostate and bladder neck, improving urine flow. Minimal action on vascular alpha-1B receptors, so orthostatic hypotension is less frequent than with non-selective alpha-blockers such as doxazosin and terazosin.

Indications

Benign prostatic hyperplasia

First line

First-line medical therapy for BPH per EAU 2023 and AUA guidelines. Dose is 0.4 mg once daily. Effect begins within 1-2 weeks. Improves Qmax (peak urinary flow rate) by 1-3 mL/s and reduces IPSS score by 3-5 points. Does not reduce prostate volume – a 5-alpha-reductase inhibitor (finasteride, dutasteride) is added when prostate volume exceeds 40 mL.

Medical expulsive therapy for ureteral stones

Adjunct

Adjunctive therapy to facilitate passage of distal ureteral stones 5-10 mm in size. Meta-analyses show tamsulosin accelerates stone passage and reduces analgesic requirements. EAU 2023 guidelines permit tamsulosin 0.4 mg for distal ureteral stones. No proven benefit for stones under 5 mm.

Practical notes

Timing and administration

Take 0.4 mg once daily, 30 minutes after the same meal each day. Swallow the capsule whole, do not chew – modified release formulation. Urinary symptoms improve within days, peak effect at 2-4 weeks.

Special situations

Before cataract surgery, the patient must inform the ophthalmologist about tamsulosin use. The drug causes intraoperative floppy iris syndrome (IFIS) – the pupil fails to dilate normally and the iris prolapses. This complicates surgery but does not make it impossible when the surgeon is forewarned. Stopping tamsulosin before surgery does not prevent IFIS – the effect persists for months.

Safety

Contraindications

Hypersensitivity to tamsulosin
History of orthostatic hypotension
Severe hepatic impairment

Serious adverse effects

Intraoperative floppy iris syndrome (IFIS) during cataract surgery
Orthostatic hypotension (less frequent than with non-selective alpha-blockers)
Priapism (extremely rare)

Common adverse effects

Retrograde ejaculation (most common side effect – up to 10%)
Dizziness
Rhinitis, nasal congestion
Asthenia

Pregnancy

This drug is intended for men. Not used in women.