The use of some synthetic cannabis can cause some disturbing side-effects, police say. (file image) Photo: AFP The synthetic 4F-MDMB-BICA was earlier linked to one fatality and a person being admitted to hospital in a serious condition. The police and the Ministry of Health are urging people to be wary of the drug and call 111 immediately if they see someone who appears to be having an adverse reaction after taking synthetic cannabis. They say harmful effects can include fast heartbeat, nausea or vomiting, seizures and temporary paralysis. The ministry's group manager addiction Richard Taylor said both agencies were taking a health approach to drug harm, working with local communities to reduce drug harm.