Final answer:
Epinephrine is used in emergencies to treat severe allergic reactions known as anaphylaxis, and it is also administered during cardiac arrest to help restore heart rhythm.
Step-by-step explanation:
Epinephrine, also known as adrenaline, is a critical medication used in two major emergencies: severe allergic reactions (anaphylaxis) and cardiac arrest. In the case of anaphylaxis, which can be potentially fatal within 20 to 30 minutes if untreated, epinephrine is used to increase blood pressure and relax bronchial smooth muscle, counteracting the life-threatening drop in blood pressure and respiratory distress caused by systemic mast cell degranulation when an allergen is encountered.
Epinephrine injections are commonly administered via EpiPens®, which are auto-injectable syringes designed for easy use, allowing individuals with severe allergies to rapidly stop a life-threatening anaphylactic response to an allergen by self-administering the drug. The second emergency where epinephrine is used is during cardiac arrest to help restore heart rhythm.