Promethazine (Phenergan)
Purpose of Medication and Method of Action
Promethazine is a phenothiazine which is very active as an antinauseant and antimotion sickness drug. It is also a strong antihistamine however its sedation side effects limit its usefulness for that purpose.
Side Effects
Drowsiness, blurred vision, dry mouth, dizziness.
Drug Interactions
Use with caution when taken with other drugs which also have sedation (sleepiness) as a side effect. The result of taking the two drugs together can be additive, i.e. more drowsiness than with each drug taken individually. Patients taking drugs to lower blood pressure may find those effects increased while taking promethazine - a period of rest before changing from a lying to standing position is advised.
Cautions and Contraindications
Caution should be exercised when driving or operating machinery while on promethazine.
Usual Dose
The usual dose is 25 mg taken before bedtime. When used for nausea it can be given as frequently as every 6 hours.
Patient Medication Information
These information sheets do not list all known side effects of the medications, only the most common side effects. For a complete list of side effects please contact your local pharmacy or the actual drug manufacturing company.