Chapter 27 Central Nervous System Sedatives and Hypnotics

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Sedatives and Hypnotics Classifications  Barbiturates  Benzodiazepines  Nonbarbiturates  Miscellaneous

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Barbiturates Act on the reticular formation area  Reduce nerve impulses to the cerebral cortex  Inhibit nerve impulse transmission by potentiating an inhibitory amino acid known as gamma-aminobutyric acid (GABA) Effects are dose related

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Effect of Barbiturates In low doses act as sedatives In higher doses act as hypnotics

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Barbiturates: Side Effects Barbiturates raise the seizure threshold  Reduce seizures  Used for treatment of status epilepticus, tetanus, and drug-induced convulsions  A select few are used as prophylaxis for epileptic seizures. (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Barbiturates: Side Effects Main side effects  Excessive central nervous system depression  Drowsiness, lethargy, dizziness, hangover  Hypersensitivity reactions  Paradoxical restlessness or excitement  Depression of the REM sleep cycle (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Barbiturates: Rebound Phenomenon When barbiturates are discontinued, a rebound phenomenon can occur  Increase in REM sleep  Dreams often become nightmares

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Benzodiazepines Affect the hypothalamic, thalamic, and limbic systems of the brain and depress the CNS Receptors resemble the GABA receptors (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Benzodiazepines Useful hypnotic agents Have a calming effect on the CNS Control agitation and anxiety Relaxes skeletal muscle Does not affect the REM sleep cycle Used in the treatment of alcohol withdrawal (continues) (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Benzodiazepines An overdose results in somnolence, confusion, coma, and diminished reflexes  Treatment is syrup of Ipecac  Activated charcoal with gastric lavage  Treatment is flumazenil (Romazicon)  Reverses the sedative effects of benzodiazepines (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Alcohol A potent CNS depressant Used to assist a person in relaxing and becoming more social

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Other Sedatives Zolpidem tartrate (Ambien)  A nonbarbiturate, nonbenzodiazepine hypnotic agent  Produces an effect similar to the benzodiazepines, but without producing muscle relaxation  Used frequently in the elderly