Anaphylaxis

Q: All of the following drugs can compound anaphylaxis reaction except? 

A) Beta-blockers (BB)
B) Angiotensin-converting enzyme inhibitors (ACE-I)
C) Acetaminophen
D) Tricyclic antidepressants (TCA)
E) Cocaine


Answer: C

Anaphylaxis is relatively hard to treat in patients who are on beta-adrenergic blockers as they cause unopposed alpha-adrenergic effects, hypertension, and reduced bronchodilator response to the beta-adrenergic effects when epinephrine is administrated (choice A).

ACE-I can potentially interfere with endogenous compensatory responses (choice B).

TCA can potentially increase in adverse effects of epinephrine because of prevention of epinephrine uptake at adrenergic receptors (choice D).

Cocaine potentiates the epinephrine's effects, especially cardiovascular effects, by preventing its reuptake into adrenergic neurons (choice E). 

Acetaminophen has no direct effect on anaphylaxis.


#Allergy
#pharmacology


Reference:

Simons FER. Anaphylaxis, killer allergy: Long-term management in the community. J Allergy Clin Immunol 2006; 117:367.