Ketamine psychedelic effects

Bowdle TA, Radant AD, Crowley DS, et al Psychedelic effects of ketamine in healthy volunteers relationship to steady-state plasmaconcentrations. Anesthesiology 88 82-88, 1988. 

The chemical structure of ketamine is similar to that of the potent psychedelic PCP (Figure 6.2). Not surprisingly, ketamine produces many psychedelic effects that are similar to those produced by PCP. However, ketamine s effects are much shorter in duration—a trip on ketamine may last only 30-60 minutes, whereas a trip on PCP may last several hours. The onset of ketamine s actions is quite rapid (i.e., within minutes), especially if snorted or injected intravenously. 

Figure 6.2 The chemical structure of ketamine (top) is related to the psychedelic PCP (bottom). Both chemicals produce strong hallucinations and psychedelic effects. However, while the effects of ketamine may only last an hour, the effects of PCP can last several hours after the drug is taken.

Physical effects of high doses of ketamine include decreased respiration and heart rate, increased blood pressure, and the possibility of vomiting and convulsions. These can lead to cardiac and respiratory arrest, coma, and death. The risk of ketamine overdose is much greater when it is mixed with other drugs such as alcohol, Ecstasy, caffeine, or cocaine. Overdoses of ketamine have been reported when people boost the drug (take another dose before the first dose wears off) to prolong its psychedelic effects. 

Ketamine is often taken with other drugs, such as cocaine, marijuana, alcohol, and Ecstasy, which greatly increases the risk for overdose. Ketamine tends to be taken by people with a history of experimenting with numerous other drugs. Ketamine is also occasionally taken by physicians and veterinarians, who have easy access to the drug and want to experiment with its psychedelic effects. 

The effects of a ketamine high usually last an hour, but they can last for 4 to 6 hours, and 24 to 48 hours are generally required before the user will feel completely normal again. Effects of chronic use of ketamine may take from several months to 2 years to disappear completely. Low doses (25 to 100 mg) produce psychedelic effects quickly. Large doses can produce vomiting and convulsions and may lead to hypoxia of the brain and muscles 1 g can cause death. Flashbacks may even occur 1 year after use. Long-term effects include tolerance and possible physical and/or psychological dependence. 

Research is needed to improve the delivery of drugs in children, either to enhance compliance via the route of choice or to identify alternative routes where the normal route of administration is unavailable or associated with severe side effects. The efficacy of administering ketamine and midazolam orally, rectally and intravenously to children receiving invasive procedures has been compared (Ozdemir et al., 2004). It was found that the alternatives routes were equally effective. The use of other routes may mitigate the usual prolonged sedation and psychedelic effects of intravenous administration of ketamine/midazolam in children. 

EXTENSIONS AND COMMENTARY There is a thread of disconnection and of inconsistent reference that pervades most of the reports that I have received concerning the use of DOPR. The word that comes to mind is hypnogogic. There is a drifting into that place that lies between a not-quite-awake and a not-quite-asleep state seems to characterize this compound. There is no question but that it is very potent, and that it is very long-lived. But there is a nagging suggestion of the out-of-body, out-of-center character that is the hallmark of the anesthetic and delusional drugs such as scopolamine or ketamine. With them, the psychedelic effects become clouded with touches of amnesia. 

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