Brands, Medical Use, Clinical Data
Drug Category
Dosage Forms
- Tablet (extended-release)
Brands / Synonyms
Uroxatral; Xatral
Indications
For the treatment of the signs and symptoms of benign prostatic hyperplasia.
Pharmacology
Alfuzosin is an alpha-adrenergic blocking agent used to treat hypertension and benign prostatic hyperplasia. Accordingly, alfuzosin is a selective inhibitor of the alpha1 subtype of alpha adrenergic receptors. In the human prostate, alfuzosin antagonizes phenylephrine (alpha1 agonist)-induced contractions, in vitro, and binds with high affinity to the alpha1c adrenoceptor, which is thought to be the predominant functional type in the prostate. Studies in normal human subjects have shown that alfuzosin competitively antagonized the pressor effects of phenylephrine (an alpha1 agonist) and the systolic pressor effect of norepinephrine. The antihypertensive effect of alfuzosin results from a decrease in systemic vascular resistance and the parent compound alfuzosin is primarily responsible for the antihypertensive activity.
Mechanism of Action
Alfuzosin acts by inhibiting the postsynaptic alpha(1)-adrenoceptors on vascular smooth muscle. This inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation.
Absorption
Absorption is 50% lower under fasting conditions
Toxicity
side effects are dizziness (due to postural hypotension), upper respiratory tract infection, headache, and fatigue.
Biotrnasformation / Drug Metabolism
Hepatic
Contraindications
Alfuzosin should not be used in patients with moderate or severe hepatic insufficiency, (Childs-Pugh categories B and C) since alfuzosin blood levels are increased in these patients. Alfuzosin should not be co-administered with potent CYP3A4 inhibitors such as ketoconazole, itraconazole, and ritonavir, since alfuzosin blood levels are increased. Alfuzosin is contraindicated in patients known to be hypersensitive to alfuzosin hydrochloride or any component of Alfuzosin tablets.
Drug Interactions
Drug-Drug Interactions: The pharmacokinetic and pharmacodynamic interactions between Alfuzosin and other alpha-blockers have not been determined. However, interactions may be expected, and Alfuzosin should NOT be used in combination with other alpha-blockers.
|