Epinephrine Flashcards
What is the drug classification of Epi?
Endogenous catecholamine
- nonselective adrenergic agonist stimulating alpha (1&2) and beta (1&2) receptors
- receptor selectivity is dose dependent
What are the uses/indications of Epinephrine?
- bronchospasm/ bronchial asthma
- Hypersensitivity rxn (allergic rxn)
- open-angle glaucoma
- Cardiac arrest, asystole
- Electromechanical dissociation
- V.Fib unresponsive to initial defibrillation
- Infusion to increase myocardial contractility
- also added to LAs to decrease systemic absorption and prolong DOA of the anesthetic
What is the MOA of Epi (hint: tell me by the dosages used, which receptors are being activated)?
- Beta 2: 1-2mcg/min IV (redistribution of BF to skeletal muscle)
- Beta 1: 4-5mcg/min IV
- Alpha and Beta: 10-20mcg/min IV (vasoconstriction
What is Epi the most potent activator of?
Alpha receptors!!!!!!!!
What are the routes of Epi?
SQ or IV
What is the onset of SQ and IV Epi?
SQ: 5-10 minutes
IV: 1-2 minutes
What is the DOA of Epi?
5-10 minutes
What is the standard bolus dose of Epi for resuscitation?
10mcg/kg IV (can start with 2-8mcg/kg)
-with single bolus dose CV effects dissipate after 1-5min
What are the CV effects of Epi?
- major role is BP regulation
- a1: Vasoconstriction-> Increase BP, CVP, Cardiac work, SVR
- a2: negative feedback-> decrease BP
- B1: increased contractility, HR, CO
- B2: Peripheral vasodilation-> decrease BP
- skin, mucosa, hepatic, renal (a1)
- B2- skeletal muscle
With moderate epi doses SBP tends to __________(B1, A1), and DBP tends to _________ (B2) and MAP _______ _____ _______
- increase
- decrease
- stay the same
What are the cerebral effects of epi?
at clinically relevant doses, MINIMAL effects on vasoconstriction of arterioles in: Cerebral, Coronary, and Pulmonary vasculature
What are the ocular effects of Epi?
- accommodation for far vision (a1-mydriasis)
- regulation of IOP (a1, a2: increase humoral flow; B1: increase production of aqueous humor)
What are the respiratory effects of Epi?
BRONCHODILATION
- dilates smooth muscles of bronchial tree (B2)
- Decreased release of vasoactive mediators (histamine) in bronchial vasculature (B2)
- Reduce mucosal secretion (decongestion) (a1)
What are the GI effects of Epi?
A2: decreased digestive secretions
a, B2: decreased peristalsis, direct smooth muscle relaxation
a1: decreased splanchnic BF (drastically reduced even if BP relatively normal)
What are the GU effects of Epi?
a1-renal BF decreased; contraction of urethral sphincter B1- increased renin release from kidney B2- relaxation- decreases UO a1-facilitates ejaculation B2- relaxation: inhibits labor!
