Phentolamine
 - Pharmacology. Phentolamine is a competitive presynaptic and postsynaptic alpha-adrenergic receptor blocker that produces peripheral vasodilation. By acting on both venous and arterial vessels, it decreases total peripheral resistance and venous return. It also may stimulate beta-adrenergic receptors, causing cardiac stimulation. Phentolamine has a rapid onset of action (usually 2 minutes) and a short duration of effect (approximately 15–20 minutes). 
 
 - Indications 
 
 - Hypertensive crisis associated with stimulant drug overdose (eg, amphetamines, cocaine, or ephedrine). Also an adjunct for cocaine-induced acute coronary syndrome to reverse coronary artery vasoconstriction. 
 
 - Hypertensive crisis resulting from interaction between monoamine oxidase inhibitors and tyramine or other sympathomimetic amines.   - Full access? Get Clinical Tree    
 
 
 
 
	 

