Promethazine is an antihistamine used to relieve allergy symptoms, prevent nausea and vomiting, and as a sedative.
The typical dosage varies depending on the condition being treated. For allergy symptoms, one to two tablets (25-50mg) may be taken every 4 to 6 hours as needed, not exceeding the prescribed amount. For motion sickness or nausea, dosage usually starts at 25mg taken before travel or as directed.
Common side effects include drowsiness, dizziness, and dry mouth. Rare but serious side effects may include severe allergic reactions, confusion, or difficulty breathing. Contact your healthcare provider if you experience severe or persistent symptoms.