Anesthetic abuse

KETAMINE An anesthetic abused for its mind-altering effects that is popular as an illicit club drug. It is sometimes used to facilitate sexual assault, or date rape. 

Zagelbaum BM, Donnenfeld ED, Perry HD, Buxton J, Buxton D, Hersh PS. Corneal ulcer caused by combined intravenous and anesthetic abuse of cocaine. Am J Ophthalmol 1993 116(2) 241-2. 

The fact that there are so many different compounds abused as inhalants brings up question of how all of these compounds act on the brain. Do they all act in the same way The answer to this question will be discussed in Chapter 4. It has been argued by some researchers that inhalant abuse should be regrouped as solvent abuse, volatile anesthetic abuse, and nitrite abuse, since the populations that abuse these substances are different." Solvents are primarily abused by teenagers, anesthetics are generally abused by older professionals who have access to them, and nitrites are abused by populations older than teenagers. In the case of nitrites, as will be discussed later, the way the chemical acts upon the body appears to be quite different as well. In this book, the differences between these subgroups of inhalants will be discussed when useful. 

If topical anesthetic abuse is suspected, discontinuation is critical. A broad-spectrum topical antibiotic such as 0.5% moxifloxacin three times daily is used to protect the disrupted corneal epithelium from secondary infection as the tissue heals. Topical NSAIDs, such as 0.1% diclofenac sodium solution or 0.5% ketorolac solution, and a therapeutic soft contact lens help to reduce pain. Cycloplegic and topical steroids are indicated if an anterior chamber reaction is present.Toxic keratitis can heal without permanent vision loss within days after discontinuing the use of the anesthetic but may result in permanent scarring, vascularization, and visual loss. Surgical treatment, such as a penetrating keratoplasty, may be necessary. 

Varga JH, Rubinfeld RS, Wolf TC, et al. Topical anesthetic abuse ring keratitis report of four cases. Cornea 1997 16 424-429. 

Topical anesthetic abuse, mostly unintentional, remains a persistent cause of keratitis and epithelial defects, leading to continuing ocular pain, visual impairment, and at worst enucleation (SEDA-21,134) (SEDA-22,140) (327). Mechanisms include direct toxicity of the local anesthetic or preservative and immunological causes. 

Rosenwasser GO, Holland S, Pflngfelder SC, Lngo M, Heidemann DG, Cnlbertson WW, Kattan H. Topical anesthetic abuse. Ophthalmology 1990 97(8) 967-72. 

Sugar A. Topical anesthetic abuse after radial keratotomy. J Cataract Refract Surg 1998 24(ll) 1535-7. 

Zipeprol [34758-83-3] (58) is another European antitussive with a wide range of pharmacological effects, including antispasmodic, antihistaminic, and local anesthetic activities (85,86). It has been reported that zipeprol has been abused in Italy because high doses cause hallucinations (87). Spontaneous withdrawal symptoms similar to those of opiates have been observed withdrawal symptoms can also be precipitated by naloxone. Zipeprol can be... 

Other anesthetics susceptible to abuse, such as ether and chloroform, have received far less attention, because they are considered to be less commonly abused substances. Nonetheless, when inhaled, ether and chloroform are also rapidly absorbed and distributed in the central nervous system (CNS), inducing a rapid euphoria. Ether and chloroform inhalation is facilitated by the fact that they have a low boiling point (i.e., approximately 34°C) (Delteil et al. 1974). 

Toluene, volatile nitrites, and anesthetics, like other substances of abuse such as cocaine, nicotine, and heroin, are characterized by rapid absorption, rapid entry into the brain, high bioavailability, a short half-life, and a rapid rate of metabolism and clearance (Gerasimov et al. 2002 Pontieri et al. 1996, 1998). Because these pharmacokinetic parameters are associated with the ability of addictive substances to induce positive reinforcing effects, it appears that the pharmacokinetic features of inhalants contribute to their high abuse liability among susceptible individuals. 

Inhalation of other general anesthetics susceptible to abuse, such as ether and chloroform, appears to be limited to health professionals who have easy access to these compounds and who tend to use these dtugs in isolation. Recreational and social use of these substances has been somewhat limited by their high flammability and by frequent and intense undesirable adverse effects at moderate doses. It has been suggested that the abuse of ether or chloroform alone is a rare phenomenon (Delteil et al. 1974 Deniker et al. 1972), occurring usually in the context of dependence on othet substances, particularly alcohol (Krenz et al. 2003). 

Is the development of ultrashort-acting (less abused) PCP derivatives that are good anesthetics and analgesics with very little respiratory depression possible ... 

Phencyclidine (PCP), a dissociative anesthetic agent, which is subject to abuse, produces behavioral effects in man that frequently resemble schizophrenia (Luisada 1978). Manifestations of persistent psychopathology frequently remain after the acute effects of PCP have diminished. With PCP, subjects may display autistic and delusional thinking typical of schizophrenics (Luby et al. 1959). A more striking link between schizophrenia and PCP comes from observations of cases in which PCP was given to hospitalized schizophrenics (Luisada 1978). After receiving PCP, these patients showed extreme exacerbation of their psychoses the reaction persisted for up to 6 weeks. By contrast, LSD produced no more severe effects in schizophrenics than in normal subjects. 

Dextromethorphan hydrobromide is the D-isomer of levorphanol. It lacks CNS activity but acts at the cough center in the medulla to produce an antitussive effect. It is half as potent as codeine as an antitussive. Anecdotal reports of abuse exist, but studies of abuse potential are lacking. It has few side effects but does potentiate the activity of monoamine oxidase inhibitors, leading to hypotension and infrequently coma. Dextromethorphan is often combined in lozenges with the local anesthetic benzocaine, which blocks pain from throat irritation due to coughing. 

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