Chapter 12 CNS Depressants and Muscle Relaxants Flashcards
sedatives
drugs with calming effect, depress the CNS, reduce nervousness, excitability , and irritability WITHOUT causing sleep
hypnotics
drugs with calming effect, depress the CNS, DO cause sleep, and more potent to the CNS
REM sleep
last third of sleep
non REM sleep
first third to half, 4 stages from drifting to very deep sleep
how many cycles of sleep per night on average?
5 cycles
benzodiazepines
- sedative hypnotics or axiolytics
-short, intermediate, and long acting types
benzodiazepines mechanism of action
depress CNS activity, effects on hypothalamus, thalamus, and limbic system
benzodiazepines indications
sedation, relief of anxiety, sleep induction (insomnia), skeletal muscle relaxation, treatment of acute seizure disorders, treatment of alcohol withdrawal
benzodiazepines counterindications
drug allergy, narrow angle glaucoma, pregnancy
benzodiazepines adverse effects
-harmful in a high dose or mixed with alcohol
-headache, drowsiness, paradoxical excitedness/nervousness, dizziness, cognitive impairment
-high fall risk!
-daytime sleepiness and sometimes withdrawal
benzodiazepines toxicity
-confusion, diminished reflexes, unresponsiveness
-can cause death if combined with barbiturates and alcohol
-don’t use with grapefruit
benzodiazepine drug examples
“Pams”
-Diazepam
-Midazolam - makes people forget what’s going on
-Temazepam- induces sleep in 30 to 40 mins, take before bedtime
nonbenzodiazepine drug examples
-Eszopiclone- long term use
-Ramelteon- similar to melatonin, used to help fall asleep
-Zolpidem- prevents daytime sleepiness
barbiturates
- very old drugs (1903)
-used for insomnia and inducing sedation
-rarely used today
barbiturates mechanism of action
-CNS depressants that act on brainstem in reticular formation
-reduce nerve impulses traveling to cerebral cortex, potentiate GABA receptors
-raise seizure threshold
barbiturates indications
-no longer recommended for insomnia
-anesthesia for short procedures, seizure control, reduction of intracranial pressure
barbiturates contraindications
known allergy, pregnancy, respiratory difficulties, severe kidney and liver disease
barbiturates adverse effects
drowsiness, lethargy, dizziness, hangover
barbiturates toxicity
-maintain airway, assisted ventilation, O2 administration, support BP
-alkalization of urine
barbiturate drug examples
-Pentobarbital - shorter, pre op
-Phenobarbital- longer acting, seizure prevention
-both reduce intracranial pressure
over the counter hypnotics
-often contain antihistamines
-Doxylamine
-Diphenhydramine
-often added to analgesics like Tylenol PM
muscle relaxants
acts on CNS to relieve pain with skeletal muscle spasms
muscle relaxants mechanism of action
-most beneficial effects are from their sedative effects rather than direct muscle relaxation
-Dantrolene acts directly on excitation / contraction of muscle fibers, all others work on the level of CNS
-decreased response of muscle to stimuli, relaxes striated muscles, weakens skeletal muscles, decreased force of muscle contraction
muscle relaxer indications
relied of painful musculoskeletal condition, chronic conditions associated with muscle spasticity
