Benzodiazepines emesis

Numerous neurotransmitter receptors are located in the vomiting center, CTZ, and GI tract. Examples of such receptors include cholinergic and histaminic, dopaminergic, opiate, serotonin, neurokinin (NK), and benzodiazepine receptors. Theoretically, chemotherapeutic agents, their metabolites, or other emetic compounds trigger the process of emesis through stimulation of one or more of these receptors. 

Recovery is sufficiently rapid with most intravenous drugs to permit their use for short ambulatory (outpatient) surgical procedures. In the case of propofol, recovery times are similar to those seen with sevoflurane and desflurane. Although most intravenous anesthetics lack antinociceptive (analgesic) properties, their potency is adequate for short superficial surgical procedures when combined with nitrous oxide or local anesthetics, or both. Adjunctive use of potent opioids (eg, fentanyl, sufentanil or remifentanil see Chapter 31) contributes to improved cardiovascular stability, enhanced sedation, and perioperative analgesia. However, opioid compounds also enhance the ventilatory depressant effects of the intravenous agents and increase postoperative emesis. Benzodiazepines (eg, midazolam, diazepam) have a slower onset and slower recovery than the barbiturates or propofol and are rarely used for induction of anesthesia. However, preanesthetic administration of benzodiazepines (eg, midazolam) can be used to provide anxiolysis, sedation, and amnesia when used as part of an inhalational, intravenous, or balanced anesthetic technique. 

Corned answer = B. The anxiolytic properties of benzodiazepines, such as lorazepam, make them the drugs of choice in treating the anxiety and agitation of cocaine withdrawal. Lorazepam also has hypnotic properties. Phenobaibital has hypnotic properties but if s anxiolytic properties are inferior to those of the benzodiazepines. Cocaine itself could countered the agitation of withdrawal but its use would not be proper therapy. Hydroxyzine, an antihistaminic, is effective as an hypnotic and is sometimes used to deal with anxiety especially if emesis is a problem. Fluoxetine is an antidepressant with no immediate effects on anxiety. 

Gastric lavage and activated charcoal are considered to be effective decontamination measures, whereas ipecac-induced emesis should be avoided after massive ingestion, because of the risk of seizures. Aggressive use of benzodiazepine is a reasonable first choice to treat associated involuntary movements, tremor, hyperactivity, and agitation. Chlorpromazine or haloperidol can also be used, especially for serious, life-threatening symptoms, including hypertensive crises and severe hyperthermia, and labetalol or sodium nitroprusside are reasonable choices for rapid stabilization of blood pressure. 

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