Final answer:
The drug that should be given to counteract the effects of anaphylaxis is epinephrine.
Step-by-step explanation:
The drug that should be given to counteract the effects of anaphylaxis is epinephrine. In cases of anaphylaxis, epinephrine is used to control the immune reaction and prevent life-threatening symptoms. Epinephrine constricts blood vessels, relaxes smooth muscles in the lungs, modulates heart rate, and reduces swelling that may block the airways.