epinefrineautoinjector

An epinephrine autoinjector, often called an epinephrine auto-injector, is a compact medical device that delivers a measured dose of epinephrine into the thigh during an anaphylactic reaction. It is designed for rapid self-administration or administration by a bystander when medical care may be delayed.

Mechanism and use: Epinephrine acts on several receptors to counteract anaphylaxis. It causes vasoconstriction, which reduces swelling and raises blood pressure; it relaxes airway smooth muscle to improve breathing; and it limits the release of inflammatory mediators. The autoinjector is the first-line treatment for suspected anaphylaxis in individuals known to be at risk or who exhibit symptoms such as throat swelling, breathing difficulties, widespread hives, vomiting, or dizziness.

Dosing and administration: Autoinjectors are available in two common dose strengths, typically 0.15 mg for some children and 0.30 mg for adults or larger children. The device is used intramuscularly in the mid-outer thigh, and it may be administered through clothing if necessary. The safety cap is removed, the device is pressed firmly against the thigh for several seconds, and then the device is removed. After use, emergency services should be contacted and the person should be taken to a medical facility for evaluation; a second dose may be required in some cases. The device should be kept on the patient at all times and replaced after use or upon expiration.

Storage, safety, and guidance: Store at room temperature away from extreme heat or cold and check expiration dates regularly. Possible side effects include rapid heartbeat, nervousness, tremor, headache, or nausea. Epinephrine is generally used in suspected anaphylaxis even if adverse effects are a concern, but it is contraindicated in those with a known true allergy only if no anaphylaxis is present.

Regulatory status: Epinephrine autoinjectors are prescription devices in many countries, with multiple brands and generic options available.