Bidirectional nystagmus is a unique finding of phencyclidine and ketamine toxicity.
Myocardial ischemia and cerebral vascular accidents are potential significant morbidities of cocaine toxicity.
There is greater morbidity associated with synthetic marijuana toxicity than for conventional marijuana; potential adverse effects include seizures, renal injury, and myocardial infarction.
Synthetic cathinone toxicity presents with the sympathomimetic toxidrome.
Recreational drugs are substances used for nonmedical purposes to enhance one’s personal experience or enjoyment. A wide range of substances are available and this chapter focuses on well-known drugs including phencyclidine, ketamine, and cocaine as well as newer “designer drugs” including synthetic marijuana and cathinone products. Other recreational drugs that are often abused in the pediatric population but are beyond the scope of this chapter include solvents, hallucinogenic mushrooms, lysergic acid diethylamide (LSD), ecstasy, and dextromethorphan.
PHENCYCLIDINE AND KETAMINE
Phencyclidine (PCP) first came to the market as a surgical anesthetic and sedative in the 1950s as Sernyl by Parke Davis Pharmaceutical Company. However, it was removed from the market due to adverse side effects such as hallucinations. In the late 1960s, PCP made its return to commercial use as a veterinary tranquilizer. It was first reported as an illicit drug used for recreational purposes in San Francisco, where it was called the “Peace Pill.” The Controlled Substance Analogue Enforcement Act of 1986 made PCP and its derivatives illegal. The drug has various street names such as “angel dust,” “hog,” “horse tranquilizer,” “crystal joint,” and “illy.”1 Marijuana cigarettes (“joints”) can be dipped in a liquid form of PCP colloquially known as “wet,” “embalming fluid,” or “formaldehyde.”2,3
Ketamine is a legal analogue of PCP used in humans for sedation and anesthesia. Ketamine is also a drug of abuse. Adolescents often use it at raves and nightclubs for the hallucinatory, out-of-body experiences it provides. It has various street names such as “Special K,” “K,” “KitKat,” and “Vitamin K.” It has a relatively short duration of action of 15 to 45 minutes, and is one-tenth as potent as PCP. Because of its abuse potential, ketamine is in the Controlled Substance Act of 1999. There have been reports of a newer designer drugs and ketamine analogues, such as methoxetamine. It is likely that additional ketamine and PCP analogues will be developed as further “legal” highs are sought.4
PHARMACOLOGY AND PATHOPHYSIOLOGY
Phencyclidine is classically categorized as a dissociative anesthetic because when anesthetized, the patient is conscious yet experiences a feeling of dissociation from themselves—the “out-of-body” experience. After ingestion, PCP absorption occurs in the upper intestine. The drug has an enterogastric circulation; it is secreted by the stomach and then absorbed in the small intestine. Because the drug recirculates in this way, it produces cyclical effects.5 It interacts at many receptor sites, but its primary mechanism of action is N-methyl-d-aspartic acid (NMDA)-type glutamate receptor antagonism.