Burn wound itch control using H1 and H2 antagonists.

This study investigated the use of a combination of H1 and H2 antagonists and topical medications to control burn wound itch. Graeco-Latin square assignment provided an oral combination of 1) cetirizine and cimetidine or 2) diphenhydramine and placebo in four divided doses. The study protocol lasted 16 days divided into 4-day intervals, scoring itch before the initial dose of medication and at 1-hour, 6-hour, and 12-hour intervals after the first medication. A significant difference between mean itch scores across the four times was observed (Wilks' Lambda F = 26.52, df = 3, P <.0005). A three-way nested repeated measures interaction effect (Wilks' Lambda F = 9.85, df = 9, P <.0005) was observed representing a significantly different pattern on days 1 to 4 of the study compared with the remaining days. Controlling for the effect of topical medications, the cetirizine/cimetidine combination demonstrated a dramatic improvement at 1 and 6 hours, and a moderate improvement at 12 hours after initial medication for the day when compared with the diphenhydramine/placebo combination.