This patient is likely suffering from an opioid overdose, which can be due to heroin, methadone, or prescription opiate medication like oxycodone. Opioid intoxication will commonly give pinpoint pupils and depressed respirations. Cocaine overdose will result in chest pain, arrhythmias, and signs of sympathetic stimulation (tachycardia, increased respiratory rate, dilated pupils, and hypertension). PCP intoxication is characterized by rage, violent outbursts and nystagmus. Ketamine is a hallucinogenic when used recreationally and is characterized by altered mental status.