Ephedrine Sulfate (Ephedrine)

Anesthesia Implications

Classification: Mixed Alpha/Beta Adrenergic Agonists
Therapeutic Effects: Vasopressor, bronchodilator
Time to Onset: IV – immediate; IM: 1-2 minutes
Time to Peak: IV: 2-5 minutes; IM: < 10 minutes
Duration: 10-60 minutes

Contraindications

Patients on MAOI therapy – use of ephedrine could lead to a hypertensive crisis

Use caution:
Patients with hypertension, tachycardia, ischemic heart disease, heart failure, depleted catecholamines

Primary Considerations

Effects – increased cardiac output, heart rate, blood pressure, coronary blood flow, skeletal blood flow, uterine blood flow, and bronchodilation.

Low blood pressure, low heart rate – Ephedrine is the ‘go to’ for most patients exhibiting a low blood pressure and low heart rate as it effectively raises both, and avoids the baroreceptor reflex (worsened bradycardia) that phenylephrine can produce.

Effectiveness – Each dose given typically has a reduced effectiveness

Oxidation – ephedrine is subject to oxidation when exposed to light. Do not use ephedrine if the solution is not clear.

increased MAC – increases MAC of volatile anesthetic anesthetics

Potential arrhythmias – when given to patients taking tricyclic antidepressants

IV push dose

Hypotension & Bronchospasm: 2.5-10 mg intial dose, titrated every 5-10 minutes.
MAX dose in 24 hours: 3mg/kg

Common Preparations
Method 1: 50 mg/ml vial.  Draw up 1 ml of ephedrine with 9 ml of crystalloid in a 10 ml syringe.  This dilutes to 5 mg/ml.
Method 2: 50 mg/ml vial.  Draw up the 1 ml of ephedrine from the vial in a 1 ml TB syringe.  Each 0.1 mark represents 5 mg

IM dose

25-50 mg

Method of Action

Ephedrine is a noncatecholamine sympathomimetic. Resistance to metabolism by monoamine oxidase and catechol-O-methyltransferase (COMT) makes ephedrine longer-lasting. Ephedrine works by direct/indirect simulation of alpha and beta adrenergic receptors. Stimulation of beta 2 receptors results in bronchodilation.

Metabolism

Hepatic

Elimination

Renal