Cyclizine is an antihistamine drug used to treat nausea, vomiting and dizziness associated with motion sickness, vertigo and post-operatively following administration of general anaesthesia and opioids. Some people using methadone recreationally combine cyclizine with their methadone dose, a combination that is known to produce strong psychoactive effects. It has also been used recreationally for its anticholinergic effects to induce hallucinations.