Hypnotics Central nervous system depressants

Q66 Hypnotic doses of diazepam may cause hyperventilation in patients with severe chronic obstructive pulmonary disease. Diazepam causes central nervous system depression. 

Buspirone is as effective as the benzodiazepines in the treatment of general anxiety. However, the full anxiolytic effect of buspirone takes several weeks to develop, whereas the anxiolytic effect of the benzodiazepines is maximal after a few days of therapy. In therapeutic doses, buspirone has little or no sedative effect and lacks the muscle relaxant and anticonvulsant properties of the benzodiazepines. In addition, buspirone does not potentiate the central nervous system depression caused by sedative-hypnotic drugs or by alcohol, and it does not prevent the symptoms associated with benzodiazepine withdrawal. 

A significant advantage of the benzodiazepines over other central nervous system depressants (e.g., the barbiturates) is that they possess a much greater separation between the dose that produces sleep and the dose that produces death. This increased margin of safety has been one of the major reasons benzodiazepines have largely replaced the barbiturates and other types of sedative-hypnotics in the treatment of anxiety and insomnia. In addition, benzodiazepine aclministration is associated with few side effects. 

When used with other sedative-hypnotics or alcohol, the benzodiazepines will produce additive central nervous system depression. 

Most of the sedative-hypnotics are capable of inhibiting the development and spread of epileptiform activity in the central nervous system. Some selectivity exists in that some members of the group can exert anticonvulsant effects without marked central nervous system depression (although psychomotor function may be impaired). Several benzodiazepines—including clonazepam, nitrazepam, lorazepam, and diazepam—are sufficiently selective to be clinically useful in the management of seizure states (see Chapter 24 Antiseizure Drugs). Of the barbiturates, phenobarbital and metharbital (converted to phenobarbital in the body) are effective in the treatment of generalized tonic-clonic seizures. 

Buspirone causes less psychomotor impairment than diazepam and does not affect driving skills. The drug does not potentiate the central nervous system depressant effects of conventional sedative-hypnotic drugs, ethanol, or tricyclic antidepressants, and elderly patients do not appear to be more sensitive to its actions. Tachycardia, palpitations, nervousness, gastrointestinal distress, and paresthesias may occur more frequently than with benzodiazepines. Buspirone also causes a dose-dependent pupillary constriction. Blood pressure may be elevated in patients receiving MAO inhibitors. A number of buspirone analogs have been developed (eg, ipsapirone, gepirone, tandospirone) and are under study. 

Like other sedative-hypnotic drugs, alcohol is a central nervous system depressant. At high blood concentrations, it induces coma, respiratory depression, and death. 

Pharmacodynamic alcohol interactions are also of great clinical significance. Additive central nervous system depression with other sedative-hypnotics is most important. Alcohol also potentiates the pharmacologic effects of many nonsedative drugs, including vasodilators and oral hypoglycemic agents. There is some evidence that alcohol also enhances the antiplatelet action of aspirin. 

SAFETY PROFILE Poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes. Human systemic effects by ingestion pulmonary consolidation. Used as a central nervous system depressant, hypnotic, and sedative. When heated to decomposition it emits toxic fumes of NOx. See also BARBITURATES. 

Barbiturates are central nervous system depressants used as hypnotic drugs and anesthetics. They are all derivatives of barbituric acid (R=R =H), which has no sedative properties. It is called an acid because the carbonyl groups render the imide hydrogens acidic ... 

Methaqualone is a central nervous system depressant similar to other sedative-hypnotics that cause enhanced gamma-aminobutyric acid activity. 

Introduction During 1966, several new types of chemical structures were reported to have central nervous system depressant activity, and further studies were described of compounds previously classified in this area. The problem of defining further the type of activity to predict whether a given depressant will be of clinical application as an antipsychotic, anti-anxiety agent, sedative, hypnotic, anti-convulsant or anesthetic continues to occupy the attention of many investigators. 

Alcohol is a central nervous system depressant that shares many pharmacologic properties with the nonbenzodiazepine sedative hypnotics. 

Subsequently, Chan reported on twenty-four cases of overdose of a product containing valerian dry extract 75 mg, hyoscine hydrobromide 0.25 mg, and cyproheptadine hydrochloride 2 mg. Six patients developed vomiting, and fifteen underwent gastric lavage. Co-ingestants included alcohol (n = 10), cold products n = 3), hypnotics (n = 2), unknown drugs (n = 2), and gasoline (n = 1). Symptoms were mainly central nervous system depression and anticholin-... 

Central nervous system depressants Hypnotics and sedatives Barbiturates in pharmaceutical preparations Ion-exchange Zipax SAX Alkaline (0.01M sodium borate/ 0.03M sodium nitrate) or acid (0.01M acid) mobile phases... 

Vida JA. Central nervous system depressants sedative-hypnotics. In Foye WO, Lemke TL, Williams DA, eds., Principles of Medicinal Chemistry, 4th Ed. Baltimore Williams Wilkinson, 1995 154-180. 

Vida JA. In Foye WO, ed. Central Nervous System Depressants Sedative-Hypnotics. Principles of Medicinal Chemistry, 2nd Ed. Philadelphia Lea Febiger, 1981. pp 173-188. 

Central nervous system depressants are medications that suppress the transmission of information throughout the central nervous system. There are seven broad classifications of central nervous system depressants. These are sedative-hypnotics, general and local anesthetics (discussed later in this chapter), analgesics, narcotic analgesics (Chapter 16), anticonvulsants, antipsychotics, and antidepressants (discussed later in this chapter)... 

Sedative-h5 notics are commonly referred to as sedatives and are the mildest form of central nervous system depressant. Sedative-hypnotics are given in low... 

A. Benzodiazepines will potentiate the central nervous system-depressant effects of opioids, ethanol, and other sedative-hypnotic and depressant drugs. 

A. Dantrolene may have additive central nervous system-depressant effects with sedative and hypnotic drugs. 

Hydromorphone should be used with caution if other central nervous system depressants are given concomitantly. These drugs are other opioids, general anesthetics, phenothiazine, tricyclic antidepressants, sedative-hypnotics, and other central nervous system depressants (including ethanol). 

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