Amnesia-inducing drugs

Amnesia-inducing drugs cause a significant decrease in the step-through latency at T2. 

Though some differences between CNS depressant drugs do exist, as a group the effects induced are very similar. They cause a state of intoxication, with signs and symptoms of euphoria, mental confusion, loss of motor coordination, blurred vision, slurred speech, nausea, vomiting, impaired judgment, decreased attention span, and amnesia. The drugs also decrease blood pressure, heart rate, and respiration. 

Prevented the amnesia induced not only by 5-HT4 receptor antagonists, but also by antimuscarinic drugs and exposure to a hypoxic environment. 61... 

It has been known for many years that antimuscarinic drugs like hyoscine, which enter the brain, cause amnesia when used clinically, e.g. pre-operatively, to reduce bronchial secretions. In experimental studies in both humans and animals they disrupt both the acquisition and the performance of learned behaviour. Anti-cholinestrase drugs have the opposite effect. It is by no means certain, however, that the memory defects induced by antimuscarinics are identical to those seen in AzD. 

Benzodiazepines have the capacity to produce a calming effect and to cause anterograde amnesia, in which the patient cannot recall events that took place for some time after the drug was administered. Benzodiazepine-induced sedation and amnesia are deemed useful in the preparation of patients for anesthesia, surgery, and other frightening or unpleasant medical and dental procedures and diagnostic tests. Midazolam is a frequently used anesthetic benzodiazepine (see Chapter 25). 

The physiologic state induced by general anesthetics typically includes analgesia, amnesia, loss of consciousness, inhibition of sensory and autonomic reflexes, and skeletal muscle relaxation. The extent to which any individual anesthetic agent can produce these effects depends on the specific drug, the dosage, and the clinical situation. 

The most widely studied aspect of cognition with respect to benzodiazepines is memory.12 163 One of the most reliable effects of benzodiazepines is to impair recall of information presented after drug administration (anterograde amnesia). In contrast, information presented before administration of benzodiazepines is not affected. The memory decrement produced by benzodiazepines is a function of task difficulty, such that little or no impairment is observed for immediate recall of a few items, whereas more complex or delayed memory tests reveal profound impairment.12 The benzodiazepine antagonist flumazenil has been used to block the sedative effects of benzodiazepines, but the amnestic effect was not affected, suggesting that benzodiazepine-induced amnesia is independent of sedation.122,164 It has also been demonstrated that some benzodiazepines selec-... 

Anterograde amnesia is another problem sometimes associated with sedative-hypnotic use.39 The patient may have trouble recalling details of events that occurred for a certain period of time before the drug was taken. Although usually a minor problem, this can become serious if the drug-induced amnesia exacerbates an already existing memory problem, as might occur in some elderly patients. 

In a placebo-controlled study of the effects of midazolam 0.5 mg/kg as a premedicant in 40 children aged 4-6 years having myringotomy, midazolam caused significant amnesia on a cued recall task (43). In addition, free recall for post-drug events was also impaired by midazolam, suggesting that benzodiazepine-induced amnesia occurs even for highly salient information. 

After ingesting street drugs sold as PCP , THC , and methadone , three young men developed schizophreniform psychoses, analgesia, anesthesia, and amnesia (14). Except for the unusually long duration (2-4 weeks), these reactions resembled phencyclidine-induced psychoses. 

A more recently recognized problem is that benzodiazepines may interfere with the storage of memories, a phenomenon called anterograde amnesia. Thus, when an individual is awakened by a phone call from sleep induced by benzodiazepines, he or she may fail to remember the phone conversation. The drug may be present in... 

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