Which medications in the drug class H2 Receptor Antagonists are used in the treatment of Anaphylaxis?

Updated: May 16, 2018
  • Author: S Shahzad Mustafa, MD; Chief Editor: Michael A Kaliner, MD  more...
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Answer

H2 Receptor Antagonists

These agents block effects of released histamine at H2 receptors, thereby treating vasodilation, possibly some cardiac effects, and glandular hypersecretion. H2 blockers with H1 blockers have additive benefit over H1 blockers alone in treating anaphylaxis. Ranitidine (Zantac) probably preferred over cimetidine (Tagamet) in anaphylaxis in light of the risk for hypotension with rapidly infused cimetidine and the multiple, complex drug interactions with cimetidine. Famotidine (Pepcid) IV is another good alternative.

Cimetidine (Tagamet)

Many H2 blockers are available. Cimetidine is the prototype drug; other agents have much less evidence of effectiveness in anaphylaxis.

Ranitidine (Zantac)

Ranitidine is an H2 antagonist, which, when combined with an H1 type, may be useful in treating allergic reactions that do not respond to H1 antagonists alone.

Famotidine (Pepcid)

H2 antagonist that when combined with an H1 type, may be useful in treating allergic reactions that do not respond to H1 antagonists alone.


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