Over taking phenergan be away for someone who has a drug problem away for them to get messed up on?

Phenergan is an antihistamine that relieves symptoms of allergies. It is also used to treat allergic reactions to blood transfusions and with other medications, anaphylactic shock (severe allergic reaction).
Phenergan is also used as a sedative and is prescribed to prevent and control nausea and vomiting before and after surgery and to prevent and treat motion sickness. It is also used, with other medications, for pain after surgery.

Phenergan (promethazine) when taken alone does not have an addictive effect. However there are combination products on the market which contain narcotic cough supressants such as codeine. The syrup combinations are quick to work and can, because of the addictive nature of narcotics, become addictive. It can be dangerous for someone to take these if they have a history of drug abuse.

Check to see what type of Phenergan product your friend is using and become more concerned if it contains codeine.
Phenergan alone, taken with other drugs of abuse could potentiate the drowsiness or light headedness side effects.

See: http://www.drugs.com/pdr/phenergan.html