Overview
Tamsulosin is an alpha-1 adrenergic receptor antagonist used to treat the signs and symptoms of benign prostatic hyperplasia (BPH). It works by relaxing smooth muscle in the prostate and bladder neck, improving urinary flow. It is not indicated for hypertension treatment.
Mechanism of Action
Selective antagonist of alpha-1A and alpha-1D adrenergic receptors in the prostate and bladder neck, causing smooth muscle relaxation and improved urinary flow without significant effects on blood pressure.
Indications
- Treatment of signs and symptoms of benign prostatic hyperplasia (BPH)
Common Doses
- 0.4 mg
- 0.8 mg
Dosage
0.4 mg once daily taken approximately 30 minutes after the same meal each day. Capsules should not be crushed, chewed, or opened. Dose may be increased to 0.8 mg once daily after 2-4 weeks if inadequate response.
Contraindications
- Hypersensitivity to tamsulosin hydrochloride or any capsule component
- History of allergic reactions including skin rash, urticaria, pruritus, angioedema, or respiratory symptoms
Side Effects
- Dizziness
- Headache
- Abnormal ejaculation
- Rhinitis
- Orthostatic hypotension
- Syncope
- Allergic reactions including skin rash and angioedema
Interactions
- Strong CYP3A4 inhibitors (e.g., ketoconazole) - avoid concomitant use with 0.4 mg dose
- Other alpha-adrenergic blockers - increased risk of hypotension
- Phosphodiesterase-5 inhibitors - additive blood pressure lowering effects
Counseling Points
- Take dose 30 minutes after the same meal each day
- Do not crush, chew, or open capsules
- Rise slowly from sitting/lying position to avoid dizziness
- Report any dizziness, fainting, or prolonged/painful erections
- Inform ophthalmologist about tamsulosin use before cataract surgery