Duodart is a medicine that contains two active substances: dutasteride (0.5 mg), and tamsulosin (0.4 mg).it belongs to a group of medicines called alpha-adrenergic antagonists (also called alpha blockers). dutasteride blocks the action of 5-alpha reductase enzymes. these enzymes convert testosterone into 5-alpha-dihydrotestosterone (dht), which is responsible for prostate hypertrophy. blocking this enzyme prevents the prostate from further growing. tamsulosin blocks alpha receptors in the prostate and bladder, relax smooth muscles of the prostate and bladder, and facilitates urination.because of such effects, it is used in the treatment of benign prostate enlargement (benign prostatic hyperplasia-bhp) and for the prevention of urinary retention.duodart should be taken half an hour after breakfast, at the same time every day. the usual dosage is one duoadart capsule per day.