(Science: drug) a cardiac drug used for cardiac arrest from ventricular fibrillation, ventricular tachycardia, asystole, or pulseless electrical activity; extreme hypotension; bradycardia and heart block.
pharmacologic action: 1. Beneficial mainly due to alpha stimulation - increases systemic vascular resistance and improves coronary and cerebral blood flow. 2. Value of beta stimulation is controversial - increases myocardial electrical activity and strength of contraction, but also increases myocardial oxygen requirements and automaticity.