Opioids such as fentanyl , morphine , heroin and methadone the notable exception being demerolpethidineproducts containing nicotine such as cigarettes , chewing tobacco or gum . Imidazolines such as clonidine , naphazoline , oxymetazoline and t e t r a hydrozolineAntipsychotics , including risperdal , haloperidol , thorazine , olanzapine , quetiapine and othersCholinergic agents such as acetylcholineOndansetron an antiemetic known by its brand name ZofranSome cancer chemotherapy drugs , including camptothecin derivativesMirtazapine , a noradrenergic and specific serotonergic antidepressant NaSSASome MAO Inhibitors . Pilocarpine eye drops and all other parasympathomimeticsIn some rare cases , when exposed to mustard gas . OrganophosphatesA complete list of drugs and narcotics which constrict your pupils , rest of the reasons are due to a variety of medical symptomscomplications .