What is phenylephrine?

(α1) selective direct-acting, synthetic adrenergic drug that binds primarily to α receptors and favors α1 receptors over α2 receptors (α1> > α2 ) not a catechol derivative -not a substrate for COMT is a vasoconstrictor that raises both systolic and diastolic blood pressures no effect on the heart itself but rather induces reflex bradycardia when given parenterally (Phenylephrine 10 mg/ml Injection) treatment of hypotensive states e.g. circulatory failure, during spinal anaesthesia Local often used topically on the nasal mucous membranes and in ophthalmic solutions for mydriasis Phenylephrine acts as a nasal decongestant and produces prolonged vasoconstriction Large doses can cause hypertensive headache and cardiac irregularities