Dosin

Doxazosin

Pharmacology
Mechanism of Action
Hypertension: Blocks postsynaptic alpha1 receptors; alpha blockade causes arterial, arteriolar, and venous dilation; decreases total peripheral resistance and blood pressure
Benign prostatic hyperplasia (BPH): Blocks alpha1 receptors in prostatic stromal and bladder tissues; reduces sympathetic tone-induced urethral stricture responsible for BPH symptoms

Absorption
Bioavailability: Immediate release, 65%; extended release, 54-59%
Onset (antihypertensive response): Peak, 4-8 hr
Onset (BPH response): Initial, 2 wk; peak, 4-6 weeks
Duration: 24 hr
Peak plasma time: 2-3 hr

Distribution
Protein bound: 99%
Vd: 1-3.4 L/kg

Metabolism
Metabolized extensively in liver
Metabolites: 6- and 7-O-demethyl metabolites, 6'- and 7'-hydroxy metabolites, other minor metabolites (activity unknown)

Elimination
Half-life: Immediate release, 22 hr; extended release, 15-19 hr
Dialyzable: HD, no
Total body clearance: 83-140 mL/min
Excretion: Feces (65%), urine (0.6-9%)

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Dosin only for the indication prescribed.