Autoinjector

An autoinjector is a medical device designed to deliver a single, premeasured dose of a drug through the skin in a rapid, user-friendly manner. Most autoinjectors are compact, disposable, and spring-loaded, containing a prefilled cartridge or syringe. Activation triggers automatic needle insertion and injection, which minimizes handling of sharps and simplifies administration. Safety features commonly include a protective cap, a one-way safety mechanism to prevent accidental discharge, and a shielded needle after use. Some models provide dose counters or audible/visual cues to confirm delivery.

The most widely known application is epinephrine auto-injectors used for the treatment of severe allergic reactions (anaphylaxis). In an emergency, the user presses the device against the outer thigh, holds for several seconds, and removes the device; medical attention is advised promptly afterward. Other auto-injectors exist for different drugs and conditions, including therapies designed for self-administration or caregiver administration, though they are less common than epinephrine devices.

Design and use: autoinjectors contain a preloaded dose and are engineered for straightforward operation, often requiring only a single action to deliver. Training devices and instructional materials are commonly provided to ensure proper use, aiming to reduce user error.

Storage and disposal: autoinjectors are typically stored at appropriate temperatures per drug specifications and kept accessible to individuals at risk. After use, devices should be disposed of according to local regulations in approved sharps containers.

Regulatory and safety: autoinjectors are regulated as medical devices and require labeling, safety warnings, and guidance appropriate to their intended use.