Ephedrine

Used for: 

• Vasopressor used to treat acute hypotension with bradycardia

Mechanism: 

• Sympathomimetic: Promotes the release of endogenous norepinephrine which activates sympathetic receptors

• After endogenous sources are exhausted, ephedrine is no longer effective (tachyphylaxis)

Physiological Effects:

• Increases BP: By inducing systemic vasoconstriction (alpha-1) and increasing heart rate and contractility (beta-1).

• Bronchodilation: Acts on beta-2 receptors

Contraindications:

• Patients with acute hypertension or tachycardia 

• Patients with ischemic heart disease or heart failure (ephedrine increases myocardial oxygen demand)