<p>Tamsulosin &amp; Dutasteride is a combination of two drugs with complementary mechanisms of action to improve symptoms in patients with Benign Prostatic Hyperplasia (BPH). Tamsulosin Hydrochloride, an antagonist of alpha1A-adrenoreceptors and Dutasteride, a dual 5 alpha reductase inhibitor (5ARI). Treatment of BPH with alpha1-adrenoreceptor blocking agents and 5ARIs results in an improvement in urine flow rate and a reduction in symptoms of BPH.<br />
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<strong>Tamsulosin</strong>: An alpha1-adrenoreceptor blocking agent that affects the dynamic component of BPH by inhibiting alpha1-adrenoreceptors in the stromal prostatic smooth muscle and bladder neck. Blockade of these adrenoreceptors can cause smooth muscles in the bladder neck and prostate to relax. Specifically, Tamsulosin exhibits selectivity for both alpha&nbsp;1A&nbsp;and alpha&nbsp;1D&nbsp;receptors over the alpha1B-adrenoreceptor subtype. These three adrenoreceptor subtypes have a distinct distribution pattern in human tissue. Whereas approximately 70% of the alpha1-receptors in human prostate are of the alpha&nbsp;1A&nbsp;subtype, the human bladder contains predominantly the alpha&nbsp;1D&nbsp;subtype while blood vessels express predominantly alpha&nbsp;1B&nbsp;subtype. It is further believed that blockade of the alpha&nbsp;1D&nbsp;subtypes in the human obstructed bladder may be responsible for reducing detrusor overactivity and subsequent relief of storage symptoms.<br />
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<strong>Dutasteride</strong>: A synthetic 4-azasteriod compound is a competitive and specific inhibitor of both Type I and Type II 5 alpha-reductase isoenzymes that affects the static component of BPH by inhibiting the conversion of Testosterone to Dihydrotestosterone (DHT) by the enzyme 5 alpha-reductase. 5 alpha-reductase exists as 2 isoforms, Type I and Type II, both of which are present in the prostate. It has been observed that compared to normal tissue, the expression of both isoenzymes are increased in BPH tissue. Dissociation from this complex has been evaluated under in vitro and in vivo conditions and is extremely slow. Dutasteride lowers DHT levels and leads to a reduction in prostatic volume, thereby treating an underlying cause of BPH. Dutasteride does not bind to the human androgen receptor.</p>