Central Nervous System Depressants Copyright 2002 1998 Elsevier

CNS Depressants Sedatives • Drugs that have an inhibitory effect on the CNS to

CNS Depressants Hypnotics • Calm or soothe CNS to the point that they cause

CNS Depressants Sedative-Hypnotics—dose dependent: • At low doses, calm or soothe CNS without inducing

Sedative-Hypnotics: Barbiturates • First introduced in 1903, standard agents for insomnia and sedation •

Sedative-Hypnotics: Barbiturates Four categories: • Ultrashort – mephobexital, thiamylal, thiopental • Short – pentobarbital,

Sedative-Hypnotics: Barbiturates have a very narrow therapeutic index. Therapeutic Index • Dosage range within

Sedative-Hypnotics: Barbiturates Mechanism of Action • Site of action: – Brain stem (reticular formation)

Sedative-Hypnotics: Barbiturates Drug Effects • Low doses: Sedative effects • High doses: Hypnotic effects

Sedative-Hypnotics: Barbiturates Therapeutic Uses • Hypnotics • Sedatives • Anticonvulsants • Surgical procedures Copyright

Sedative-Hypnotics: Barbiturates Side Effects Body System Effects CNS Drowsiness, lethargy, vertigo depression, coma Respiratory

Sedative-Hypnotics: Barbiturates Side Effects Body System GI Effects Nausea, vomiting, diarrhea Other Agranulocytosis, vasodilation,

Sedative-Hypnotics: Barbiturates Toxicology • Overdose frequently leads to respiratory depression, and subsequently, respiratory arrest.

Sedative-Hypnotics: Barbiturates Drug Interactions • Additive effects: – ETOH, antihistamines, benzodiazepines, narcotics, tranquilizers •

CNS Depressants: Benzodiazepines Most frequently prescribed sedative-hypnotics • Most commonly prescribed drug classes •

CNS Depressants: Benzodiazepines Classified as either: • Sedative-hypnotic or Anxiolytic (Medication that relieves anxiety)

CNS Depressants: Benzodiazepines Sedative-Hypnotic Type • Long-Acting: – flurazepam (Dalmane), quazepam (Doral) • Short-Acting:

CNS Depressants: Benzodiazepines Anxiolytic Type • alprazolam (Xanax) • chloridiazepoxide (Librium) • diazepam (Valium)

CNS Depressants: Benzodiazepines Mechanism of Action • Depress CNS activity • Affect hypothalamic, and

CNS Depressants: Benzodiazepines Drug Effects • Calming effect on the CNS • Useful in

CNS Depressants: Benzodiazepines Therapeutic Uses • Sedation • Sleep induction • Skeletal muscle relaxation

CNS Depressants: Benzodiazepines Side Effects • Mild and infrequent Headache Drowsiness Dizziness Vertigo Lethargy

CNS Depressants: Nursing Implications • Before beginning therapy, perform a thorough history regarding allergies,

CNS Depressants: Nursing Implications • Give 15 to 30 minutes before bedtime for maximum

CNS Depressants: Nursing Implications • Check with physician before taking any other medications, including

CNS Depressants: Nursing Implications • Safety is important – Keep side rails up –

CNS Depressants: Nursing Implications • Monitor for therapeutic effects – Increased ability to sleep

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CNS Depressants Sedatives • Drugs that have an inhibitory effect on the CNS to the degree that they reduce: – Nervousness – Excitability – Irritability – without causing sleep Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants Sedative-Hypnotics—dose dependent: • At low doses, calm or soothe CNS without inducing sleep • At high doses, calm or soothe CNS • to the point of causing sleep Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates • First introduced in 1903, standard agents for insomnia and sedation • Habit-forming • Only a handful commonly used today due in part to the safety and efficacy of: BENZODIAZEPINES Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates Four categories: • Ultrashort – mephobexital, thiamylal, thiopental • Short – pentobarbital, secobarbital • Intermediate – aprobarbital, butabarbital • Long – phenobarbital Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates have a very narrow therapeutic index. Therapeutic Index • Dosage range within which the drug is effective but above which is rapidly toxic. Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates Mechanism of Action • Site of action: – Brain stem (reticular formation) – Cerebral cortex • By inhibiting GABA, nerve impulses traveling in the cerebral cortex are also inhibited. Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates Drug Effects • Low doses: Sedative effects • High doses: Hypnotic effects (also lowers respiratory rate) Notorious enzyme inducers Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates Side Effects Body System Effects CNS Drowsiness, lethargy, vertigo depression, coma Respiratory depression, apnea, bronchospasms, cough Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. mental

Sedative-Hypnotics: Barbiturates Side Effects Body System GI Effects Nausea, vomiting, diarrhea Other Agranulocytosis, vasodilation, hypotension, Johnson syndrome Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Stevens-

Sedative-Hypnotics: Barbiturates Toxicology • Overdose frequently leads to respiratory depression, and subsequently, respiratory arrest. • Can be therapeutic: – Anesthesia induction – Uncontrollable seizures: “phenobarbital coma” Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Sedative-Hypnotics: Barbiturates Drug Interactions • Additive effects: – ETOH, antihistamines, benzodiazepines, narcotics, tranquilizers • Inhibited metabolism: – MAOIs will prolong effects of barbiturates • Increased metabolism: – Reduces anticoagulant response, leading to possible clot formation Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Benzodiazepines Most frequently prescribed sedative-hypnotics • Most commonly prescribed drug classes • Favorable side effects • Efficacy • Safety Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Benzodiazepines Sedative-Hypnotic Type • Long-Acting: – flurazepam (Dalmane), quazepam (Doral) • Short-Acting: – estazolam (Prosom), temazepam (Restoril), – triazolam (Halcion) Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Benzodiazepines Anxiolytic Type • alprazolam (Xanax) • chloridiazepoxide (Librium) • diazepam (Valium) • lorazepam (Ativan) • midazolam (Versed) zolpidem (Ambien) and zaleplon (Sonata) (nonbenzodiazepine hypnotic agents, share characteristics) Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Benzodiazepines Mechanism of Action • Depress CNS activity • Affect hypothalamic, and limbic systems of the brain • Benzodiazepine receptors Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Benzodiazepines Therapeutic Uses • Sedation • Sleep induction • Skeletal muscle relaxation • Anxiety relief • Treatment of alcohol withdrawal • Agitation • Depression • Epilepsy • Balanced anesthesia Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Benzodiazepines Side Effects • Mild and infrequent Headache Drowsiness Dizziness Vertigo Lethargy Paradoxical excitement (nervousness) “Hangover effect” Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Nursing Implications • Before beginning therapy, perform a thorough history regarding allergies, use of other medications, health history, and medical history. • Obtain baseline vital signs and I & O, including supine and erect BPs. • Assess for potential disorders or conditions that may be contraindications, and for potential drug interactions. Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Nursing Implications • Give 15 to 30 minutes before bedtime for maximum effectiveness in inducing sleep. • Most benzodiazepines (except flurazepam) cause REM rebound a tired feeling the next day; use with caution in the elderly. • Patients should be instructed to avoid alcohol and other CNS depressants. Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Nursing Implications • Check with physician before taking any other medications, including OTC medications. • It may take 2 to 3 weeks to notice improved sleep when taking barbiturates. • Abruptly stopping these medications, especially barbiturates, may cause rebound insomnia. Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Nursing Implications • Safety is important – Keep side rails up – Do not permit smoking – Assist patient with ambulation (especially the elderly) – Keep call light within reach • Monitor for side effects Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

CNS Depressants: Nursing Implications • Monitor for therapeutic effects – Increased ability to sleep at night – Fewer awakenings – Shorter sleep induction time – Few side effects, such as hangover effects – Improved sense of well-being because of improved sleep Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.