CASE REPORT   

Gazzetta Medica Italiana - Archivio per le Scienze Mediche 2020 November;179(11):638-40

DOI: 10.23736/S0393-3660.19.04227-X

Copyright © 2019 EDIZIONI MINERVA MEDICA

lingua: Inglese

A case of ketamine poisoning

Giuseppe DIPAOLA, Luigi CASTORANI ✉

Ketamine is a molecule of synthetic origin, produced in 1962 by Calvin Stevens and patented in Belgium in 1963. It has anesthetic and analgesic properties. It is widely used in the veterinary field and as an anesthetic in humans, mainly for pediatric use. In the illicit market it is in the form of liquid, capsules and crystalline powder. The analgesic, anesthetic and memory effects of ketamine are mainly due to the non-competitive antagonism on the NMDA receptor (N-methyl-D-aspartate). A dose-dependent inhibition of the re-uptake of norepinephrine, dopamine and serotonin neurotransmitters is documented, with a consequent increase in monoaminergic neurotransmission in the brain. Ketamine, in its pharmacological action, also involves opioid receptors, determining its analgesic effect. In recreation, ketamine in powder form is mainly taken by inhalation or injected after having brought it into solution. It is also taken orally, rectally and through smoking. Ketamine is a dissociative anesthetic that induces a loss of response not only to pain stimuli, but also to the surrounding environment, and generates a feeling of dissociation of the mind from the body (“out-of-body experience”). In hospital medical use, analgesia is obtained with doses lower than 1 mg / kg intravenously and with doses of 100-300 mg orally. Anesthesia is obtained with intramuscular doses of 6.5-13 mg / kg; analgesia with 0.2-0.75 mg / kg intravenous. Typically, in recreational use the doses are: 75-125 mg (intramuscular or subcutaneous); 60-250 mg (intranasal); 50-100 mg (intravenous); 200-300 mg (oral). Ketamine rapidly develops tolerance so as to lead to a gradual increase in doses to achieve the desired effects, with unknown toxicological implications. The recreational use of ketamine can also develop psychological dependence. Ketamine, unlike other anesthetics, stimulates the cardiovascular system producing changes in heart rate (tachycardia) and blood pressure. It is a weak depressor of the respiratory system and at recreational doses it hardly produces respiratory insufficiency, even if it cannot be completely excluded. In the field of recreational low-dose use, ketamine involves attention, learning and memory disorders; at high doses it produces hallucinatory state, similar to the dream state, at even higher doses it can lead to delirium and amnesia. The reported dissociative effect is known in the medical field as Near-Death Experience or Out-of-Body Experience. For this reason, ketamine is often referred to as an “entheogenic” substance. The signs and symptoms of ketamine overdose include hypertension, tachycardia, headache, nausea, vomiting, drowsiness and, in severe cases, temporary loss of consciousness, respiratory failure or cardiac arrest. Today it is possible to access numerous Internet sites that allow you to get to ketamine and other drug retailer sites. In this case report we describe an acute ketamine intoxication in a 26-year-old male, his clinical effects and in particular his dreamlike activity.

KEY WORDS: Ketamine; Illicit drugs; Poisoning