Final answer:
Intramuscular epinephrine should be administered at the first signs of anaphylaxis, which include severe drop in blood pressure, respiratory distress, and swelling of the tongue and throat, to rapidly counteract the life-threatening symptoms.
Step-by-step explanation:
When to Administer Intramuscular Epinephrine for Anaphylaxis
Anaphylaxis is a systemic and potentially life-threatening type I hypersensitivity reaction that can be fatal if not treated promptly. When an individual experiences symptoms such as a severe drop in blood pressure, respiratory distress, or swelling of the tongue and throat, it indicates a need for immediate treatment with intramuscular epinephrine, commonly delivered via an auto-injector like an EpiPen®. Epinephrine works quickly to constrict blood vessels, thereby increasing blood pressure, relax smooth muscles in the lungs to facilitate breathing, modulate heart rate, and reduce swelling. Patients with known severe allergies are advised to carry epinephrine injectors with them at all times, especially when outside the immediate reach of medical facilities. The auto-injector can be used even through clothing and should be administered at the first sign of anaphylaxis for rapid intervention.