Hypnotic drug dependence

Assessment of the patient receiving a sedative or hypnotic drug depends on die reason for administration and whether the drug is given routinely or as needed. 

Adverse reactions associated with administration of the miscellaneous sedatives and hypnotics vary depending on the drug used. Common adverse reactions include dizziness, drowsiness, headache, and nausea Other adverse reactions that may be seen with the administration of miscellaneous sedatives and hypnotics are listed in the Summary Drug Table Miscellaneous Sedatives and Hypnotics. 

Sedation is an intermediate degree of CNS depression, while hypnosis is a degree of CNS depression similar to natural sleep. From the chemical point of view, soporific, sedative, and hypnotic drugs are classified as barbiturates, benzodiazepine hypnotics, and so on. Except for a few rare exceptions, any one of these compounds can be used for acquiring a sedative effect or state of sleep. Presently, the less toxic benzodiazepines are edging out the class of barbiturates more and more because of the possibility of chronic dependence associated with the use of barbiturates. Drugs of both classes are primarily CNS depressants, and a few of their effects, if not all, are evidently linked to action on the GABA-receptor complex. 

Most anxiolytic and sedative-hypnotic drugs produce dose-dependent depression of central nervous system function. The ideal anxiolytic drug should calm the patient without causing too much daytime sedation and drowsiness and without producing physical or psycho-... 

Withdrawal from long-term high-dose use of alcohol or sedative-hypnotic drugs can be life threatening if physical dependence is present. Benzodiazepines, such as chlordiazepoxide Librium) and diazepam Valium), are sometimes used to lessen the intensity of the withdrawal symptoms when alcohol or sedative-hypnotic drug use is discontinued. Benzodiazepines are also employed to help relieve the anxiety and other behavioral symptoms that may occur during rehabilitation. 

Buspirone causes less psychomotor impairment than benzodiazepines and does not affect driving skills. The drug does not potentiate effects of conventional sedative-hypnotic drugs, ethanol, or tricyclic antidepressants, and elderly patients do not appear to be more sensitive to its actions. Nonspecific chest pain, tachycardia, palpitations, dizziness, nervousness, tinnitus, gastrointestinal distress, and paresthesias and a dose-dependent pupillary constriction may occur. Blood pressure may be significantly elevated in patients receiving MAO inhibitors. 

Metabolic transformation to more water-soluble metabolites is necessary for clearance of sedative-hypnotics from the body. The microsomal drug-metabolizing enzyme systems of the liver are most important in this regard, so elimination half-life of these drugs depends mainly on the rate of their metabolic transformation. 

Finally, very rapid onset benzodiazepines have been widely reported as a means of "date rape," by using a small tasteless dose of the drug to make the victim incapable of protecting herself (or himself). This produces intoxication but not dependence. The drug most commonly used in this situation has been flunitrazepam (Rohypnol, "roofies," not available in the USA) and more recently GHB. The amnesia-producing effects of the benzodiazepines (see Chapter 22 Sedative-Hypnotic Drugs) make the victim unable to describe the events after she or he has recovered. 

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