07 Cns Depressants Upd

Sedatives
Drugs that have an inhibitory effect on the CNS to the degree that they reduce:
Nervousness
Excitability
Irritability
without causing sleep

Hypnotics
Calm or soothe the CNS to the point that they cause sleep

Sedative-Hypnotics—dose dependent:
At low doses, calm or soothe the CNS without inducing sleep
At high doses, calm or soothe the CNS
to the point of causing sleep

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

Four categories:
Ultrashort
mephobexital, thiamylal, thiopental
Short
pentobarbital, secobarbital
Intermediate
aprobarbital, butabarbital
Long
phenobarbital

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

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.

Drug Effects
Low doses: Sedative effects
High doses: Hypnotic effects (also lowers respiratory rate)
Notorious enzyme inducers

Therapeutic Uses
Hypnotics
Sedatives
Anticonvulsants
Surgical procedures

Side Effects
Body System Effects
CNS Drowsiness, lethargy, vertigo mental depression, coma
Respiratory Respiratory depression, apnea, bronchospasms, cough

Side Effects
Body System Effects
GI Nausea, vomiting, diarrhea
Other Agranulocytosis, vasodilation, hypotension, Stevens-Johnson syndrome

Toxicology
Overdose frequently leads to respiratory depression, and subsequently, respiratory arrest.
Can be therapeutic:
Anesthesia induction
Uncontrollable seizures: “phenobarbital coma”

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

Most frequently prescribed sedative-hypnotics
Most commonly prescribed drug classes
Favorable side effects
Efficacy
Safety

Classified as either:
Sedative-hypnotic or Anxiolytic
(Medication that relieves anxiety)

Sedative-Hypnotic Type
Long-Acting:
flurazepam (Dalmane), quazepam (Doral)
Short-Acting:
estazolam (Prosom), temazepam (Restoril),
triazolam (Halcion)

Anxiolytic Type
alprazolam (Xanax)
chloridiazepoxide (Librium)
diazepam (Valium)
lorazepam (Ativan)
midazolam (Versed)
zolpidem (Ambien) and zaleplon (Sonata)
(nonbenzodiazepine hypnotic agents, share characteristics)

Mechanism of Action
Depress CNS activity
Affect hypothalamic, thalamic, and limbic systems of the brain
Benzodiazepine receptors

Drug Effects
Calming effect on the CNS
Useful in controlling agitation and anxiety

Therapeutic Uses
Sedation
Sleep induction
Skeletal muscle relaxation
Anxiety relief
Treatment of alcohol withdrawal
Agitation
Depression
Epilepsy
Balanced anesthesia

Side Effects
Mild and infrequent
Headache Drowsiness Dizziness Vertigo Lethargy Paradoxical excitement (nervousness) “Hangover effect”

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.

Give 15 to 30 minutes before bedtime for maximum effectiveness in inducing sleep.
Most benzodiazepines (except flurazepam) cause REM rebound and a tired feeling the next day; use with caution in the elderly.
Patients should be instructed to avoid alcohol and other CNS depressants.

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.

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

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

http://bicolnurses.blogspot.com	1153
http://www.slideshare.net	13
http://bicolnurses.blogspot.in	5
http://www.bicolnurses.blogspot.com	3
http://bicolnurses.blogspot.ca	3
http://bicolnurses.blogspot.de	2
http://static.slidesharecdn.com	1
http://translate.googleusercontent.com	1
http://bicolnurses.blogspot.pt	1
http://bicolnurses.blogspot.mx	1
http://bicolnurses.blogspot.ae	1

07 Cns Depressants Upd

by Nurse Uragon on May 13, 2008

Accessibility

Categories

Upload Details

Usage Rights

11 Embeds 1,184

Statistics

07 Cns Depressants Upd Presentation Transcript