Phenoxy benzamine

Phentolamine is a non-selective alpha-adrenoceptor antagonist. It is used to treat hypertensive crises attributable to the effects of noradrenahne, as in pheochromo-cytoma and during the interaction of monoamine oxidase inhibitors with amine-containing medicaments and foods (1). Its adverse effects are similar to those of phenoxy-benzamine. 

The use of a adrenoceptor blockers (e.g. phenoxy-benzamine 0.7mg/kg orally four times a day, ace-promazine 0.02-0.04 mg/kg i.m. or orally four times a day) in combination with bethanechol decreases urethral sphincter tone in horses with bladder paresis (Schott 1998). In theory, partial relaxation of the urethral sphincter could improve bladder emptying at lower intravesicular... 

After completion of determination of the control dose-response curve, the receptor preparation is treated to reduce the number of active receptors. There are numerous methods to do this a common method is through chemical alkylation. For the example shown, the tissue is treated with phenoxy-benzamine 10 pM for 12 min. After treatment, the tissue is washed for 60 min with fresh physiological salt solution. It should be noted that there are specific protocols for these treatments unique for different receptors. 

Those agents that interact with calcium channels but have another primary site of action include agents acting on sodium channels (local anesthetics and phenytoin), catecholamine receptors (benextramine, nicergoline, phenoxy-benzamine, phenothiazines, pimozide, propranolol, and yohimbine derivatives), benzodiazepine receptors (diazepam and flurazepam), opiate receptors (loperamide and flu-peramide), and cyclic nucleotide phosphodiesterases (amrinone, cromoglycate, and papaverine), as well as barbiturates, cyproheptadine, indomethacin, and reserpine. 

A traveler to your city visits you with a request for a renewal of his prescription for phenoxy-benzamine. While preparing to telephone his physician, you recall that phenoxybenzamine is used in the treatment of all of the following EXCEPT (A) Carcinoid... 

Phenoxy- benzamine (Dibenzyline) a1, a2 Irreversible alkylation of alpha receptor. Vasodilation (a1). Blocks sympathetic outflow from the brain and feedback inhibition of norepinephrine release at [Pg.22]

Other drugs used are phentolamine and phenoxy-benzamine, alpha-lytic drugs that produce relaxation of the smooth muscle of the arterial wall and of... 

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