In the adult severe asthma (2nd bundle), what is the IM epinephrine dose?

• A. 0.1 mg IM
• B. 0.05 mg IM
• C. 0.5 mg IM
• D. 1.0 mg IM

Answer: (C)

The question tests choosing an effective IM epinephrine dose for an adult with a severe asthma attack when rapid bronchodilation is needed. The recommended amount is 0.5 mg given intramuscularly using a 1:1000 concentration. This dose provides strong bronchodilation by stimulating beta-2 receptors in the airways and helps reduce airway edema through alpha-adrenergic effects, which is crucial when inhaled therapies aren’t enough.

Smaller doses like 0.05 mg or 0.1 mg are too low to produce meaningful bronchodilation in a severe attack, while 1.0 mg would raise the risk of significant cardiovascular side effects such as tachycardia and hypertension. Therefore, 0.5 mg IM is the best choice for effective, safe immediate management in this scenario.