Which drug is given intramuscularly for anaphylaxis?

• A. Adrenaline
• B. Glucagon
• C. Suture scissors
• D. Torque ratchet

Answer: (A)

Adrenaline given intramuscularly is the first-line treatment for anaphylaxis because it acts quickly on multiple body systems to counter the life-threatening features of the reaction. By stimulating alpha-1 receptors, it causes vasoconstriction that raises blood pressure and reduces swelling in the airways. Stimulating beta-2 receptors relaxes bronchial smooth muscle, improving breathing, while beta-1 effects on the heart help maintain cardiac output. The intramuscular route in the thigh provides rapid absorption with a favorable safety profile for initial management, reserving IV administration for more controlled settings if needed. Dosing is typically 0.3–0.5 mg of a 1:1000 solution for adults, with repetition if symptoms persist; children receive a weight-based dose up to about 0.3 mg per dose. Glucagon has other indications such as hypoglycemia or certain overdoses, and the remaining options are not drugs used to treat anaphylaxis.