Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Sominex
Introduction
Sominex is the antihistamine Diphenhydramine in the United States, and is sold over the counter (OTC). Promethazine hydrochloride is the antihistamine ingredient in the UK version of Sominex, and is also sold OTC.