Epinephrine Uses

Epinephrine is used for emergency treatment of severe allergic reactions in adults and children caused by foods, drugs, insect stings, and other allergens. This drug is also used to dilate (widen) the pupil during intraocular (eye) surgery in adults and children. It is also used to increase blood pressure in adult patients with hypotension (low blood pressure) due to septic shock (a serious widespread infection). Other uses of epinephrine may include cardiopulmonary resuscitation in cardiac arrest and to relax the smooth muscle in the airways during severe asthma exacerbations. 

There may be other uses of epinephrine—your doctor or health system pharmacists can give you further drug information.

Epinephrine Mechanism of Action

Epinephrine acts on both alpha-adrenergic receptors and beta-adrenergic receptors in the sympathetic nervous system. It relaxes the smooth muscle of the airways, making it easier to breathe. It also tightens blood vessels and affects blood flow in various organs. Epinephrine leads to contraction of the dilator muscles in the pupils, thereby dilating or widening the pupils. When given by intravenous injection, epinephrine causes a rapid increase in systolic blood pressure and heart rate. It also stimulates the heart muscle and increases the strength of ventricular contraction. This drug causes constriction (narrowing) of the small blood vessels in the skin and mucosa, which can help reduce swelling and hives associated with allergic reactions. Epinephrine also stimulates glycogenolysis in the liver, which leads to increased blood sugar levels and provides immediate energy.

Epinephrine Doses

The prefilled automatic injection device contains a single fixed dose of epinephrine. EpiPen Auto-Injector contains 0.3 mg epinephrine injection (0.3 mL, 1:1000) for use by people weighing 30 kg (66 pounds) or more. The EpiPen Jr Auto-Injector contains 0.15 mg epinephrine injection (0.3 mL, 1:2000) for use by people weighing 15 to 30 kg (33 - 66 pounds).

You may need to take more than one dose of epinephrine for a severe or persistent life-threatening allergic reaction such as anaphylaxis. More than two sequential epinephrine doses should only be given under direct medical supervision.