And amnesia

Ethanol is classified for medical purposes as a central nervous system (CNS) depressant. Its effects—that is, being drunk—resemble the human response to anesthetics. There is an initial excitability and increase in sociable behavior, but this results from depression of inhibition rather than from stimulation. At a blood alcohol concentration of 0.1% to 0.3%, motor coordination is affected, accompanied by loss of balance, slurred speech, and amnesia. When blood alcohol concentration rises to 0.3% to 0.4%, nausea and loss of consciousness occur. Above 0.6%, spontaneous respiration and cardiovascular regulation are affected, ultimately leading to death. The LD50 of ethanol is 10.6 g/kg (Chapter 1 Focus On). 

FIGURE 31.15 Variation of percent heat shrinkage and amnesia rating with radiation doses of low-density polyethylene/ethylene-vinyl acetate (LDPE/EVA) film from 50 50 blend without ditrimethylol propane tetra-crylate (DTMPTA). (From Chattopadhyay, S., Chaki, T.K., and Bhowmick, A.K., Radiat. Phys. Chem., 59, 501, 2000. With permission.)... 

Benzodiazepines, especially lorazepam, are used to prevent and treat CINV.5,10 Lorazepam is thought to prevent input from the cerebral cortex and limbic system from reaching the central vomiting center in the brain stem.10 Sedation and amnesia are common side effects. Respiratory depression can occur with high doses or when other central depressants such as alcohol are combined with benzodiazepines. 

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). 

Snodgrass J, Corwin J Pragmatics of recognition memory application to dementia and amnesia. J Exp Psychol Gen 117 34-50, 1988 Snyder F The dynamic aspects of sleep disturbances in relation to mental illness. Biol Psychiatry 1 119-130, 1969... 

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. 

It may be used to produce light sedation and amnesia for unpleasant procedures by intravenous injection. It has also been used for induction and to supplement nitrous oxide anaesthesia. The benzodiazepines are further discussed in chapter Sedative and hypnotics in detail. 

Adverse effects include drowsiness, dizziness, agitation and amnesia. 

In the doses usually used, atropine has minimal stimulant effects on the CNS, especially the parasympathetic medullary centers, and a slower, longer-lasting sedative effect on the brain. Scopolamine has more marked central effects, producing drowsiness when given in recommended dosages and amnesia in sensitive individuals. In toxic doses, scopolamine, and to a lesser degree atropine, can cause excitement, agitation, hallucinations, and coma. 

For sedation and amnesia before and during medical and surgical procedures... 

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. 

GHB was first synthesized in 1960 and introduced as a general anesthetic. Because of its narrow safety margin and its addictive potential, it is not available in the USA for this purpose at present. Before causing sedation and coma, GHB causes euphoria, enhanced sensory perceptions, a feeling of social closeness, and amnesia. These properties have made it a popular "club drug" that goes by colorful street names such as "liquid ecstasy,"... 

Several other formal features of Huxley s trance condition are of interest with respect to the analogy we have drawn with REM sleep dreaming. We first consider the relaxed posture, indicating a step on the path to cataplexy. In full-blown cataplexy, the assumption of a flaccid posture is associated with the inability to move on command and is thus similar to the active motor paralysis of REM sleep dreams. Anesthesia and amnesia were both present in Huxley s trance, although they tended to be selective, and when Huxley attempted to make them global, his trance deepened. Time distortion, a distinctive component of the orientational instability of dreams, was a robust aspect of Huxley s altered state. 

The most serious side effects of efavirenz are psychiatric symptoms, rash and nervous symptoms. The psychiatric symptoms include suicide thoughts, depression, paranoia, manic disorders and aggressive behavior the rashes include macu-lopapular skin eruptions and life-threatening Stevens-Johnson syndrome has also been reported. The neurological symptoms are difficulty in concentration, insomnia, dizziness, confusion, agitation, hallucinations and amnesia. Additional side effect may include an increase in cholesterol and hepatic transaminase levels. 

Benzodiazepines Decrease anxiety and tension provide sedation and amnesia Chlordiazepoxide Diazepam Lorazepam IM 50-100 mg 1 hour before surgery IM or IV 5-10 mg prior to surgery IM 0.05 mg/kg body weight (4 mg maximum] 2 hours before surgery IV 0.044-0.05 mg/kg body weight (4 mg maximum] 15 to 20 minutes before surgery... 

Atropine To prevent excess salivation and bradycardia Scopolamine hi obstetrics, to produce sedation and amnesia Cardiology Atropine ... 

Lorazepam (Ativan, and others) is used as an adjunct to antiemetic regimens, particularly in patients with anticipatory vomiting. Alprazolam (Xanax) has also been used as an adjunct. Benzodiazepines can cause somnolence and amnesia lasting for several hours, which may be beneficial. 

Flunitrazepam (Rohypnol), also known as roofies, is a benzodiazepine with physiological effects similar to diazepam (Valium), although it is about 10 times more potent. The drug produces sedative-hypnotic effects that include muscle relaxation and amnesia it can also produce physical and psychological dependence. It is illegal and not approved for use in the United States. 

Adjunctive use of potent opioids (eg, fentanyl and related compounds) contributes cardiovascular stability, enhanced sedation, and profound analgesia. Other intravenous agents such as the benzodiazepines (eg, midazolam, diazepam) have slower onset and recovery features and are rarely used for induction of anesthesia. However, preanesthetic administration of benzodiazepines can be used to provide a basal level of sedation and amnesia when used in conjunction with other anesthetic agents. 

Many benzodiazepines have potent hypnotic activity and are useful in the treatment of insomnia. Examples include flurazepam (Dalmane, A.93), midazolam (Versed, A.94), temazepam (Restoril, A.95), and triazolam (Halcion, A.96) (Figure A.28). Flunitrazepam (Rohypnol, A.97) is a particularly notorious sedative. Often called roofie or the date rape drug, flunitrazepam causes sedation and amnesia. Because of flunitrazepam s tendency to be abused, almost all nations tightly regulate the drug s availability. 

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