Epinephrine Auto-Injectors

What is epinephrine?

Epinephrine is a drug used most often in emergency situations for animals (e.g., anaphylaxis, cardiopulmonary resuscitation/CPR). 

Automatic injection devices for epinephrine (EpiPen®, EpiPen® Jr) are used off-label in pets to treat anaphylactic (allergic) reactions that occur away from the veterinary hospital.

Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How is epinephrine given with an auto-injector?

• Epinephrine comes as a liquid solution in an auto-injector. The dose of epinephrine in the auto-injector is pre-measured for one injection into the muscle (IM). Your veterinarian may also provide pre-measured syringes of epinephrine to be used like an EpiPen.
• Follow your veterinarian’s directions and give this medication exactly as prescribed. 
• Keep this medication easily accessible. Consider attaching it to the leash, crate, or something that always travels with the animal.
• Speed up absorption by gently massaging the site of the shot.
• When handling an epinephrine auto-injector, do not remove the blue safety release until ready to use and never place your hand or fingers over the orange tip, as this is where the needle comes out of the cartridge. If you accidentally inject yourself, contact your physician immediately. 

This medication should take effect immediately and improvement in clinical signs should follow.

What if I miss giving my pet the medication?

Epinephrine is reserved for use in emergency situations. If you do not have epinephrine available and your pet starts having an allergic reaction, contact your veterinarian or emergency animal services immediately.

Are there any potential side effects?

It is recommended to contact your veterinarian after giving this drug for follow-up instructions. Epinephrine may cause the following side effects:

• increased heart rate
• nervousness, restlessness, and excitement
• nausea and vomiting
• increased blood pressure
• repeated injections to the same area of tissue may cause damage to the tissue

Are there any risk factors for this medication?

There are no absolute contraindications in life-threatening situations. Epinephrine should be USED WITH CAUTION in pets:

• with diabetes
• with high blood pressure
• with an abnormal heart rhythm
• with a low circulating blood volume
• that are pregnant, nursing, or giving birth

Are there any drug interactions I should be aware of?

Certain medications may interact with epinephrine and so it is important to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is using before starting any new treatment.

Several medications should be used with caution when given with epinephrine, including:

• alpha-2-adrenergic agonists (e.g., detomidine, dexmedetomidine, medetomidine, xylazine) 
• alpha-adrenergic antagonists (e.g., phenoxybenzamine, phentolamine, prazosin)
• antihistamines
• beta-adrenergic antagonists (e.g., atenolol, propranolol, sotalol)
• bronchodilators (e.g., albuterol, terbutaline)
• digoxin
• isoproterenol
• levothyroxine
• monoamine oxidase inhibitors (e.g., amitraz, selegiline)
• nitrates (e.g., nitroglycerin)
• oxytocin
• phenothaizines (e.g., acepromazine)
• phenylpropanolamine
• reserpine
• tricyclic antidepressants (e.g., amitriptyline, clomipramine)

Is any monitoring needed with this medication?

Be sure to follow up with your veterinarian after giving epinephrine and follow their instructions for monitoring.

How do I store epinephrine auto-injectors?

• Store auto-injectors at about 25°C. 
• The auto-injectors should not be stored in the refrigerator or a glove box. 
• The auto-injectors should not be exposed to extreme heat or cold. 
• The epinephrine should be inspected periodically for particulate matter and discoloration. If any is noted, then throw the epinephrine away.
• Keep away from children and other animals.
• Check expiration date and refill before expiration date.

Ask your veterinarian for specific disposal instructions. Do not flush medicines down the sink or toilet unless instructed to do so.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet's weight and symptoms.