Final answer:
Epinephrine is a vasopressor that may be used for an anaphylactic reaction or a cardiac arrest. It constricts blood vessels and increases heart rate to counteract the effects of anaphylaxis.
Step-by-step explanation:
The vasopressor that may be used for an anaphylactic reaction or a cardiac arrest is Epinephrine. Epinephrine is a hormone and neurotransmitter that constricts blood vessels and increases heart rate.
It is commonly used in emergencies to raise blood pressure and counteract the effects of anaphylaxis. For example, when someone experiences an anaphylactic reaction to an allergen, an epinephrine injection can help alleviate symptoms by constricting blood vessels and opening airways, preventing severe drop in blood pressure.