H2-antihistamines for the treatment of anaphylaxis with and without shock: a systematic review

Wheezing

“…68 Antihistamine use in acute allergic reactions has not been effectively studied. 69,70 A small trial 71 in patients with acute allergic syndromes found some benefit in cutaneous symptoms but lacked sufficient power to detect an effect on anaphylaxis or bronchospasm.…”

Recognition, Treatment, and Prevention of Anaphylaxis

“…[12][13][14][15][20][21][22] However, the quality of evidence is presently insufficient to permit recommendations concerning their use. [9][10][11][35][36][37] Antihistamines Skidgel and colleagues 38 provide a detailed review of H 1 and H 2 antihistamine pharmacology. Antihistamines act much more slowly than epinephrine; they have minimal favorable influence on blood pressure and they should not be administered alone for anaphylaxis treatment.…”

“…[8][9][10][11] Pending a stronger evidence base for the treatment of anaphylaxis, practice parameters and consensus emergency management guidelines afford the best clinical guidance. [12][13][14][15] However, physicians and other health care professionals may not follow them.…”

Kounis syndrome: a narrative review

“…100 Although most guidelines advocate the use of anti-histamines and glucocorticoids, no robust studies confirming the effectiveness of these treatments exist. 95,101 However, in those with type I variant and milder grades of anaphylaxis, hydrocortisone (1-2 mg/kg/day) and H 1 plus H 2 -antihistamines (diphenhydramine 1-2 mg/kg and ranitidine 1 mg/kg) may be adequate treatment. 102 Refractory anaphylaxis should be managed with a continuous infusion of vasopressors rather than IV boluses, but only by those experienced with their use.…”