1. Drugs Affecting the Central Nervous System

2. CNS Depressants: Benzodiazepines
A commonly prescribed drug class
Favorable drug effect profiles, efficacy, and safety

3. Benzodiazepines Classified as either: Sedative-hypnotic
Anxiolytic (medication that relieves anxiety)

4. Benzodiazepines: Sedative-Hypnotic Types
Long-acting
estazolam ,lorazepam
Short-acting
temazepam ,alprazolam

5. Benzodiazepines: Mechanism of Action
Depress CNS activity
Affect hypothalamic, thalamic, and limbic systems of the brain

6. Benzodiazepines: Drug Effects
Calming effect on the CNS
Useful in controlling agitation and anxiety
Reduce excessive sensory stimulation, inducing sleep

7. Side effects
Findout…

8. Benzodiazepines: Indications
Sedation
Sleep induction
Skeletal muscle relaxation
Anxiety relief
Treatment of alcohol withdrawal

9. Sedative-Hypnotics: Barbiturates
First introduced in 1903; were the standard drugs for insomnia and sedation
Habit forming; low therapeutic index
Only a handful commonly used today due in part to the safety and efficacy of benzodiazepines

10. Therapeutic Index
Dosage range within which a drug is effective but above which it is rapidly toxic
Barbiturates have a very narrow therapeutic index

11. Barbiturates: Mechanism of Action
Site of action
Brainstem (reticular formation)
By inhibiting GABA, nerve impulses traveling in the cerebral cortex are also inhibited

12. Barbiturates: Drug Effects
Low doses: sedative effects
High doses: hypnotic effects (also lower respiratory rate)
Notorious enzyme inducers
Stimulate liver enzymes that cause metabolism or breakdown of many drugs
Result in shortened duration of action

13. Barbiturates: Indications
Hypnotics
Sedatives
Anticonvulsants
Anesthesia for surgical procedures

14. Barbiturates: Adverse Effects
Body System Adverse Effects
CNS Drowsiness, lethargy, vertigo, mental depression, others
Respiratory Respiratory depression, apnea, bronchospasms, cough

15. Barbiturates: Toxicity and Overdose
Overdose frequently leads to respiratory depression and subsequent respiratory arrest
Overdose produces CNS depression (sleep to coma and death)

16. phenobarbital secobarbital
Common Barbiturates
phenobarbital
secobarbital

17. CNS Depressants: Nursing Implications
Before beginning therapy, obtain 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

18. Nursing Implications
Give hypnotics 30 to 60 minutes before bedtime for maximum effectiveness in inducing sleep (depends on drug’s onset)
Instruct patients to avoid alcohol and other CNS depressants

19. Nursing Implications (cont’d)
Check with physician before taking any other medications, including over-the-counter medications
Rebound insomnia may occur for a few nights after a 3- to 4-week regimen has been discontinued

20. Nursing Implications (cont’d)
Safety is important
Keep side rails up, or use bed alarms
Do not permit smoking
Assist patient with ambulation (especially the elderly)
Keep call light within reach
Monitor for adverse effects