Christchurch Doctors are warning of a dodgy batch of the drug ecstasy after nine patients turned up at the emergency department on Saturday night.

They all had symptoms and side effects associated with having taken a substance containing MDMA, more commonly known as ecstasy.

Christchurch Hospital's Medical toxicologist Paul Gee says they arrived in an agitated state, with heart symptoms such as a racing heart or chest pain.

"Shortness of breath, panic and some unusual ones such as being unsteady on their feet, grinding teeth and most of them had some degree of agitation or confusion."

He says they want people to be safe and not use that batch of drugs if they have any left.