autoinjektor

An autoinjektor, also known as an auto-injector, is a compact medical device that enables the user to deliver a predefined dose of a medication through the skin with a single, rapid action. Most devices are pre-filled and spring-loaded, designed for self-administration or administration by a bystander in an emergency. The device typically includes a protective cap, a needle shield, a trigger mechanism, and a plunger that drives the needle into the tissue and delivers the dose before it retracts or is shielded.

The most common use is emergency treatment of anaphylaxis with epinephrine. Epinephrine auto-injectors are widely prescribed for people at risk of severe allergic reactions and are intended to be used at the first signs of a reaction. While epinephrine is the best-known application, autoinjectors have been developed for other medications in specific clinical settings, though insulin is usually delivered with insulin pens or syringes rather than a true auto-injector.

Operation is typically straightforward and can be performed with one hand: the device is pressed firmly against the outer thigh until an audible signal confirms administration, held in place for a few seconds, and then discarded in a sharps container. After use, the needle is shielded to reduce the risk of needlestick injuries.

Storage and handling require adherence to temperature and shelf-life guidelines; devices should be checked regularly for expiration and replaced as needed. They are usually prescribed for emergency use and may be subject to regulatory and training requirements in different countries.