A fixed-dose combination (FDC) medication used primarily for the treatment of moderate to severe symptoms of Benign Prostatic Hyperplasia (BPH). Tamsulosin is a selective alpha-1A adrenergic receptor antagonist that relaxes smooth muscle in the prostate and bladder neck, improving urine flow. Dutasteride is a dual 5-alpha reductase inhibitor (Type I and II) that reduces intraprostatic dihydrotestosterone (DHT), leading to a decrease in prostate volume. This combination provides both rapid symptomatic relief (from Tamsulosin) and long-term disease modification by reducing prostate size and risk of complications (from Dutasteride).
Adult: One capsule (Tamsulosin 0.4mg + Dutasteride 0.5mg) orally once daily, approximately 30 minutes after the same meal each day (preferably breakfast or dinner).
Note: Swallow the capsule whole with a glass of water. Do not crush, chew, or open the capsule, as this can affect the modified-release properties of tamsulosin. Should be taken after a meal at the same time each day to ensure consistent absorption, particularly for dutasteride. If a dose is missed, take it as soon as remembered unless it is almost time for the next dose. Do not double the dose.
The combination works via two complementary mechanisms to relieve BPH symptoms and alter disease progression. Tamsulosin selectively blocks postsynaptic alpha-1A adrenoceptors, which are predominant in the prostate stroma, prostatic capsule, and bladder neck. This blockade inhibits noradrenaline-induced smooth muscle contraction, leading to relaxation, reduced dynamic obstruction, and improved urinary flow. Dutasteride inhibits both Type I and Type II isoforms of the enzyme 5-alpha reductase, which converts testosterone to the more potent androgen dihydrotestosterone (DHT). This inhibition drastically reduces intraprostatic and serum DHT levels, causing apoptosis of prostate epithelial cells, reduction in prostate gland volume, and thus a decrease in the static component of bladder outlet obstruction.
Pregnancy: Pregnancy Category X (US FDA). Dutasteride is contraindicated in women who are or may become pregnant. It can cause abnormalities of the external genitalia in a male fetus if absorbed through the skin or ingested. Women of childbearing potential should avoid handling broken or leaking capsules. If contact occurs, wash immediately with soap and water.
Driving: May cause dizziness, vertigo, or somnolence, which can impair the ability to drive or operate machinery. Patients should be cautioned, especially at the start of therapy, until their individual response is known.
| Other Alpha-1 Blockers (e.g., Prazosin, Terazosin, Doxazosin, Alfuzosin) | Additive hypotensive effects, increased risk of orthostatic hypotension and syncope. | Major |
| Phosphodiesterase-5 Inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil) | Additive blood pressure-lowering effects, leading to symptomatic hypotension. | Major |
| Strong CYP3A4 Inhibitors (e.g., Ketoconazole, Itraconazole, Ritonavir, Clarithromycin) | May increase plasma concentrations of both tamsulosin and dutasteride, increasing the risk of adverse effects, especially hypotension. | Moderate to Major |
| Antihypertensives (e.g., Beta-blockers, ACE Inhibitors, Calcium Channel Blockers, Diuretics) | Potential additive blood pressure-lowering effect, increasing risk of dizziness and hypotension. | Moderate |
| Cimetidine | May increase tamsulosin levels by reducing its metabolism. | Moderate |
| Warfarin | Dutasteride has been shown to have no clinically significant interaction, but monitoring is always prudent when adding new drugs. | Minor |
Same composition (Tamsulosin (0.4mg) + Dutasteride (0.5mg)), different brands: