Dosing regimen for injectable cetirizine

Abstract

Described herein is a method of administering injectable cetirizine or levocetirizine to treat acute urticaria, with or without concomitant angioedema, without life-threatening airway swelling by intravenously injecting a human patient within minutes to hours of developing acute urticaria in an emergency department or clinic with a therapeutically effective amount of an injectable cetirizine or levocetirizine composition. In the method, the injectable cetirizine or levocetirizine is the only treatment administered in the emergency department or clinic. The method can include determining, by the patient, a patient rated pruritus severity score at a 1 hour assessment, and optionally at a 2 hours assessment, and a physician discharging the human patient after 1.7±0.9 hours in the emergency department or clinic, wherein the human patient has a patient rated pruritus severity score reduction of at least 1 unit and baseline sedation at the time of discharge.