BMA Concise Guide to Medicine & Drugs

Epinephrine (Adrenaline)

Brand names Anapen, EpiPen, Minijet

Used in the following combined preparation Several local anaesthetics (e.g. Xylocaine)

QUICK REFERENCE

Drug group Drug for cardiac resuscitation and anaphylaxis

Overdose danger rating High

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Epinephrine is a neurotransmitter that is produced in the centre (medulla) of the adrenal glands, hence its original name, adrenaline. Synthetic epinephrine has been made since 1900. The drug is given in an emergency to stimulate heart activity and raise low blood pressure. It also narrows blood vessels in the skin and intestine.

Epinephrine is injected to counteract cardiac arrest, or to relieve severe allergic reactions (anaphylaxis) to drugs, food, or insect stings. For patients who are at risk of anaphylaxis, it is provided as a pre-filled syringe for immediate self-injection into a muscle at the start of an attack.

Because it constricts blood vessels, epinephrine is used in preparations of local anaesthetics to slow the dispersal, and thereby prolong the effect, of the anaesthetic.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Injection.

Frequency and timing of doses As directed; by itself, the drug is for use in emergencies.

Dosage range As directed.

Onset of effect Within 5 minutes.

Duration of action Up to 4 hours.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Not applicable. By itself, the drug is used for one-off emergencies.

Stopping the drug Not applicable. By itself, the drug is used for one-off emergencies.

OVERDOSE ACTION

Seek immediate medical advice in all cases. Take emergency action if palpitations, breathing difficulties, or loss of consciousness occur.

POSSIBLE ADVERSE EFFECTS

The principal adverse effects of epinephrine are related to its stimulant action on the heart and central nervous system. Dry mouth, nervousness, restlessness, nausea, vomiting, cold hands and feet, palpitations, headache, and blurred vision are common. As epinephrine by itself is used in emergencies, medical help should always be sought after its use.

INTERACTIONS

General note Epinephrine may interact with a wide variety of drugs, including monoamine oxidase inhibitors (MAOIs); tricyclic antidepressants such as amitriptyline; some beta blockers, such as propranolol; and antidiabetic drugs. However, because epinephrine is usually used only to treat life-threatening medical emergencies, possible drug interactions are usually of secondary importance.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have a heart problem.

· You have an overactive thyroid gland.

· You have high blood pressure.

· You are taking other medications, especially a beta blocker.

Pregnancy Discuss with your doctor. Although the drug may cause defects in the fetus and prolong labour, epinephrine by itself is used only for medical emergencies and its use may be life-saving.

Breast-feeding Adverse effects on the baby are unlikely. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 Increased likelihood of adverse effects. Reduced dose may therefore be necessary.

Driving and hazardous work Not applicable. By itself, the drug is used for one-off emergencies.

Alcohol No known problems.

Surgery and general anaesthetics Epinephrine may interact with some general anaesthetics. If you have used or been treated with epinephrine within the past 24 hours, discuss this with your doctor or dentist before surgery.

PROLONGED USE

Epinephrine is not normally used long term.