Efficacy of antihistamine pretreatment in the prevention of adverse reactions to Hymenoptera immunotherapy: a prospective, randomized, placebo-controlled trial.
BACKGROUND
Some clinical studies suggest that a combination of an H1- and H2-antagonist may be effective in the prophylaxis of allergic reactions.


OBJECTIVE
The efficacy of pretreatment with an H1/H2-antagonist combination, H1-antagonist alone, or placebo in the prophylaxis of local and systemic adverse reactions to specific immunotherapy with Hymenoptera venom was compared.


METHODS
In a prospective, randomized, double-blind, placebo-controlled study, 121 patients with Hymenoptera venom allergy were treated with rush immunotherapy and pretreatment with one of the following: 120 mg of terfenadine plus 300 mg of ranitidine, 120 mg of terfenadine alone, or placebo. The incidence of unwanted systemic adverse and local reactions was recorded for up to 50 weeks.


RESULTS
In seven patients (6%), six in the placebo group and one in the terfenadine group, systemic side effects required cessation of therapy (p = 0.005). Subjective symptoms occurred in four patients (10%) in the terfenadine plus ranitidine group and in three patients (7%) in the terfenadine group. Regarding local reactions, significantly fewer patients treated with a combination of terfenadine and ranitidine and with terfenadine alone as compared with placebo had severe local symptoms of erythema (29%, 29%, and 49%), edema (24%, 18%, and 41%), and pruritus (13%, 11%, and 31%) at week 1 (p < 0.05). This therapeutic benefit was limited to the first 4 weeks of treatment. Treatment with a combination of terfenadine and ranitidine was not superior to treatment with terfenadine alone.


CONCLUSIONS
Pretreatment with H1-antihistamines with or without H2-antihistamines significantly reduced local and systemic adverse reactions to immunotherapy with Hymenoptera venom and may therefore be helpful in the management of immunotherapy.
Brockow
K
K
Department of Dermatology and Allergy Biederstein, Technical University Munich, München, Germany.
Kiehn
M
M
Riethmüller
C
C
Vieluf
D
D
Berger
J
J
Ring
J
J
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001180:Arthropod Venoms / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D003888:Desensitization, Immunologic / Q000009:adverse effects*; D004359:Drug Therapy, Combination; D004487:Edema / Q000139:chemically induced / Q000517:prevention & control; D004890:Erythema / Q000139:chemically induced / Q000517:prevention & control; D005260:Female; D006634:Histamine H1 Antagonists / Q000627:therapeutic use*; D006635:Histamine H2 Antagonists / Q000627:therapeutic use*; D006801:Humans; D006927:Hymenoptera / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D011446:Prospective Studies; D011537:Pruritus / Q000139:chemically induced / Q000517:prevention & control; D011899:Ranitidine / Q000627:therapeutic use*; D016593:Terfenadine / Q000627:therapeutic use*
D001180:Arthropod Venoms; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D010919:Placebos; D016593:Terfenadine; D011899:Ranitidine