> Does anyone know of any H2 blocker other than cimetidine having been > shown effective for allergic rxns? The only H2 blocker our hospital carries is > famotidine (Pepcid) - po and parenteral for iv push. Any anectdotals? The greatest experience is with the use of cimetidine because it has been around the longest. But famotidine has been used sucessfully for anaphylactoid reactions (1) and urticaria (4), ranitidine and famotidine for cutaneous reactions to food allergies (2), raniditdine for chronic urticaria (3) etc. Offhand I don't see why one could not use any H2 blocker for this indication. Some studies have found H2s to be useful as single agents, others only in combination with H1 blockers and a few to offer to additional advantage to the use of H1 alone. H. Louzon MD (1) Vidovich RR, Heiselman DE, Hudock D Treatment of urokinase-related anaphylactoid reaction with intravenous famotidine. Ann Pharmacother 1992 Jun;26(6):782-3 OBJECTIVE: We describe our experience with an anaphylactoid reaction to urokinase and the treatment used. We also discuss the use of histamine H1- and H2-blockers in combination for the treatment of allergic anaphylactoid reactions. DESIGN: Case report. SETTING: Hospital. PARTICIPANTS: Observation of a patient who had a pulmonary embolism. INTERVENTION: During the use of urokinase, in treatment of a pulmonary embolism, the patient developed an anaphylactoid reaction that did not respond to diphenhydramine or hydrocortisone. Famotidine was administered. RESULTS: Abatement of urticaria and normalization of vital signs were obtained soon after famotidine was given. Completion of thrombolysis took place. CONCLUSIONS: Further investigation of the use of H1- and H2-blocking agents in the presence of anaphylactoid reactions to thrombolytic agents should be performed. Consideration of intravenous famotidine for the treatment of anaphylactoid-type reactions to urokinase is suggested. (2) Ciprandi G, Scordamaglia A, Ruffoni S, Pizzorno G, Ferrini O, Canonica GW Terfenadine (single or associated) treatment of adverse reactions to foods. Allergol Immunopathol (Madr) 1987 Jul-Aug;15(4):201-3 Six groups of patients (total 105), affected by cutaneous signs and symptoms related to food ingestion were studied with regards to the clinical efficacy of some pharmacologic treatments: blind placebo, terfenadine alone, terfenadine associated with pirenzepine or rosaprostol or ranitidine or famotidine. Pharmacologic treatment by terfenadine alone showed poor clinical results, similar to placebo, while the associations of terfenadine with both cytoprotective drugs and anti-H2 receptor antagonists revealed significant clinical improvement which is more evident in those patients treated with cytoprotective drugs combination than those who were treated with anti-H2 antagonists. (3) Paul E, Bodeker RH Treatment of chronic urticaria with terfenadine and ranitidine. A randomized double-blind study in 45 patients. Eur J Clin Pharmacol 1986;31(3):277-80 45 patients with chronic urticaria were randomized to double blind therapy with terfenadine an H1-antihistamine or ranitidine, an H2-antihistamine, or a combination of both drugs. The therapeutic response was assessed by diary scores. The primary effect variable was "itching". The inference-statistical evaluation of the patient scores showed varying therapeutic effects. The Type-I error was p = 0.015. Itching was reported to be significantly lower by patients receiving both drugs than by those who were given terfenadine alone, while ranitidine in monotherapy had no significant effect on itching. A similar trend was seen in assessment of the severity of weals, while the treatment regimens had no influence on swelling. (4) Pontasch MJ, White LJ, Bradford JC Oral agents in the management of urticaria: patient perception of effectiveness and level of satisfaction with treatment. Ann Pharmacother 1993 Jun;27(6):730-1 OBJECTIVE: Orally administered diphenhydramine, famotidine, and cromolyn sodium were compared for their abilities to alleviate symptoms of acute urticaria. DESIGN AND SETTING: This was a prospective, randomized, blind study, implemented in the emergency departments (EDs) of two teaching hospitals, each with an annual average of 40,000 ED patient visits. Patient perception of the effectiveness of treatment was assessed using a visual analog scale. PATIENTS: 33 adult patients presenting to the EDs were entered into the study over a one-year period. Of these, 8 were lost to follow-up and 5 were noncompliant with medications and not included in data analysis. Twenty adult patients, aged 19-78 years, completed the five-day study: 7 received diphenhydramine, 6 received famotidine, and 7 received cromolyn sodium. RESULTS: Patients receiving diphenhydramine reported the greatest satisfaction with treatment: 86 percent (6/7) indicated they would use the medication again. Fifty percent (3/6) in the famotidine group and 43 percent (3/7) in the cromolyn sodium group rated the treatment as worth using again. Patients receiving famotidine reported the greatest occurrence of adverse effects (50 percent, 3/6); the lowest incidence of such effects was seen in the cromolyn sodium group (14 percent, 1/7). Patients receiving diphenhydramine reported adverse effects at a rate of 43 percent (3/7). CONCLUSIONS: Our results suggest that patients receiving diphenhydramine are more satisfied with their treatment than are patients receiving famotidine or cromolyn sodium.