Background: Hypersensitivity reactions are exemplified by appearance of cutaneous manifestations and may be accompanied by gastrointestinal symptoms. These reactions occur upon exposure to an immunogen. Antihistamines of the HI type are the mainstays of therapy. Recent evidence points to the emerging role of H2-antagonists in the treatment of allergic reactions.

Objective: This study aims to compare the efficacy of administering an intravenous combination of the "conventional" dipl|Enhydramine (50mg) and hydrocortisone (200mg) with an intravenous combination of diphenhydramine (50mg) and famotidine (20mg) in the treatment of allergic reactions.

Study Design: This is a prospective, randomized, single-blind, non-placebo controlled experimental therapeutic trial.

Setting: The Emergency Department of the Makati Medical Center.

Study Population: All male and female patients aged 15-60 years old with symptoms of allergic reactions presenting to the Emergency Department within 24 hours from symptom onset. Subject selection was done by non-probability or convenience sampling.

Intervention: Patients were divided into two treatment groups after simple randomization and given either of the drug combinations under study. Patients were blinded as to what treatment was administered. Patients were evaluated at 15-minute intervals from the time of drug administration for a maximum of two hours.

Outcome Measures: The outcome measures used to compare the efficacy of the treatment given were the 10-mm Visual Analogue scale and a devised 10-point Erythema-, Rash- and Angioedema Scale. Data collected were statistically analyzed using the t-test, Chi-square test, Mann Whitney U test and Analysis of Variance.

Results: Patients in the diphenhydramine-famotidine group had a markedly earlier and faster resolution of the symptoms of erythema and rashes accompanied by a significant decrease in the VAS scores as compared to the diphenhydramine-hydrocortisone group. Patients in the hydrocortisone group had better response in terms of angioedema. Patients belonging to the famotidine group were discharged 15 minutes earlier on the average as compared to patients in the other treatment group.

Conclusion: An intravenous combination of diphenhydramine and famotidine is generally more effective for the treatment of hypersensitivity reactions in the emergency room setting. (Author)
Objectives
To compare the efficacy of administering an intravenous combination of the "conventional" diphenhydramine (50mg) and hydrocortisone (200mg) with an intravenous combination of diphenhydramine (50mg) and famotidine (20mg) in the treatment of allergic reactions.

Makati Medical Center Proceedings, 2004 (18) pages 21-31