Ketamine and phencyclidine (PCP) are chemically related anesthetics. These drugs are often used to adulterate or pass for other hallucinogens such as lysergic acid diethylamide (LSD).
Ketamine is available in liquid or powder form. When used illicitly, the powder form is typically snorted but can be taken orally. The liquid form is taken IV, IM, or subcutaneously. IM and IV ketamine is increasingly being used therapeutically for sedation and pain control.
PCP, once common, is no longer being legally manufactured. It is illegally manufactured and sold on the street under names such as angel dust; it is sometimes sold in combination with herbs, marijuana, and tobacco.
Intoxication, characterized by a giddy euphoria, occurs with lower doses; euphoria is often followed by bursts of anxiety or mood lability.
Overdose causes a withdrawn state of depersonalization and disassociation; when doses are higher still, disassociation can become severe and response to external stimuli is impaired, with combativeness, ataxia, dysarthria, muscular hypertonicity, nystagmus, hyperreflexia, and myoclonic jerks. With very high doses, acidosis, hyperthermia, tachycardia, severe hypertension, seizures, and coma may occur; deaths are unusual.
Acute effects generally fade rapidly and many patients regain normal consciousness in 45 minutes to several hours.
Diagnosis is usually clinical. Ketamine is not detected by routine urine drug screens; gas chromatography and mass spectroscopy testing can be requested when ketamine use must be confirmed.