Adrenaline is the drug of choice for first-line treatment of anaphylaxis because it works quickly to reverse the symptoms of an anaphylactic reaction.
When adrenaline is injected into the muscle of the thigh it acts quickly to constrict blood vessels, which helps to stop swelling around the face and lips, and relaxes the lungs, which improves breathing. Adrenaline also stimulates the heart, and helps raise lowered blood pressure.
The sooner the injection is given the better and you should seek professional medical assistance immediately after using your Adrenaline. You should be prepared to administer a second Adrenaline after 5 -15 minutes if there is no improvement or if original symptoms return.