Its primarily a medication as well as hormone Its an emergency drug Its direct sympathomimetics drugs Its 1 st line drug used incardiac arrest At low dose , beta effect (vasodilators ) on vascular system predominant At high dose , alpha effect ( vasoconstrictor ) are strongest
Chemical Structure molecular weight = 183.2 . Epinephrine solution deteriorates rapidly On exposure to air or light, turning pink from oxidation to adrenochrome and brown from the formation of melanin.
Routes IV Intratracheal Continous infusion nebulisation
Metabolism Epinephrine is rapidly inactivated in the body and is degraded by enzymes in the liver and other tissues. The larger portion of injected doses is excreted in the urine as inactivated compounds and the remainder either partly unchanged or conjugated. The drug becomes fixed in the tissues and is inactivated chiefly by enzymatic transformation to metanephrine or normetanephrine either of which is subsequently conjugated and excreted in the urine in the form of sulfates and glucuronides .
Indication Anaphylactic shock Prolonged action of LA Cardiac arrest Bronchospasm Chronic orthostatic hypotension Topically , to stop bleeding Minimal dysfunction of brain
Dose La without adrenaline is 300mg or 4.4 mg/kg With adrenaline is 500mg or 7mg/kg Epineprine dilution of 1: 50000and 1: 100000 are considerably more effective
Epinephrine in lA Advantage Prolongs duration of action of la by keeping them in contact with nerve fibers Limits systemic absorption Decreasing possibility of systemic toxicity cause rate of metabolism will match rate of absorption Decreases bleeding ( improves visualization ) Disadvantage Makes injection more painful Increase chances of local injury and necrosis May raise blood pressure and promote arrhymias
ADR Stinging Alergic lid rxn Systemic hypertension Arrythmia Throbbing headache , Tremor Palpitation T eratogenic effects
Contraindication Severe hypertension Cardiac disease Thyrotoxicosis