Drug Reactions

Question 1

After anaphylaxis has been ruled out and all potential offending drugs are stopped, a patient with urticaria should be treated with. . .

Answer 1

• For mild cases of urticaria only:
  
  • H1 blockers (diphenylhydramine or cetirizine)
• For severe cases of urticaria or if angioedema is present:
  
  • intravenous glucocorticoids (e.g., methylprednisolone), H1 blockers (e.g., diphenhy-dramine or cetirizine), and H2 blockers (e.g., cimetidine)

The H1 and H2 blockers decrease urticaria and angioedema while corticosteroids combat delayed recurrence (especially of angioedema). If signs of anaphylaxis (hypotension, respiratory compromise) develop, intramuscular epinephrine is indicated.