CNS depressants and muscle relaxers Flashcards
Sedatives
- drugs that have an inhibitory effect on the CNS
- Nervousness, excitability, irritability
Hypnotics
- cause sleep
- much more potent effect on CNS than sedatives
- a sedative can become a hypnotic if given in a large enough dose
Benzodiazepines
- sedative-hypnotic
- anxiolytic
- depress CNS activity (sedation(
- control agitation and anxiety
- induce skeletal muscle relaxation
- induce sleep
-treatment of acute seizure disorders - treatment of alcohol withdrawal
- useful in providing balanced anesthesia
- used in moderate sedation
Benxodiazepines (contradindications)
drug allergy
narrow-angle galucome
- pregnancy
Benzodiazepines (adverse effects)
-headaches
- drowsiness
- dizziness
- cognitive impairment
-vertigo
-lethargy
- fall risk for older adults
- “hangover”effect
Benzodiazepines (toxicity and overdose)
-somnolence
- confusion
-coma
-diminished reflexes
-can cauase hypotension and respiratory depression if taken with other CNS depressants
-treatment of overdose:flumazenil is antidote
Benzodiazepines (interactions)
-azole antifungals, verpamil, diltiazem, protease inhibitors, macrolide antibiotics, grapefruit juice (inhibits p-450 enzymes)
- CNS depressants (alcohol, opioids)
- rifampin
- herbal interaction (kava and valerian: increases CNS depression)
- Opioids (black box warning for Benzo + Opioids)
Kava (Herbal products)
-used to relieve anxiety, stress, and restlessness and to promote sleep
- may cause temporary skin discoloration (extended continued intake) and visual disturbances
- potential interactions with alcohol, barbiturates, and psychoactive drugs
- contraindicated in liver disease, alcoholism, and other conditions
- the patient should not operate heavy machinery during use
Valerian (Herbal prodcut)
-used to relieve anxiety, restlessness, and sleep disorders
- may cause CNS depression, hepatotoxicity, nausea, vomiting, anorexia, restlessness, insomnia
- many interactions, including CNS depressants, MAOIs, phenytoin, warfarin and alcohol
- contraindicated in cardiac and liver disease
- patients should not operate heavy machinery during use
Diazepam (valium)
- benzodiazepine
- first benzo clinically available
- antianxiety, procedural sedation, anesthesia adjunct
-oral, injectable rectal
Midazolam (versed)
- benzodiazepine
- used most commonly preoperatively and for moderate sedation
- causes amnesia, sedation, and anxiolysis
- injectable and oral (for children)
Temazepam (Restoril)
-intermiedate acting benzo
- used for sleep - induces sleep within 20-40 minutes, instruct patients to take it about 1 hour prior to going to bed
Eszopiclone (Lunestra)
- first hypnotic to be FDA-approved for long-term use
- provides 8 hours of sleep
- Patients should not take this medication if they will not be able to get 8 hours of sleep
Zolpidem (Ambien)
- short-acting hypnotic
- lower incidence of daytime sleepiness than benzodiazepines
Adverse Effects: somnambulation
Ramelteon (Rozerem)
-strucutrally similar to the hormone melatonin
- not a controlled substance
- indicated for patients who have difficulty with sleep onset rather than sleep maintenance
Suvorexant (Belsomra)
- orexin-receptor antagonist
- 12 hours half-life
- adverse effects: drowsiness, HA, dizziness, diarrhea, dry mouth, cough, increased serum cholesterol
Barbiturates
-1st introduced in 1903-used to be the standard drug for insomnia and sedation
- habit forming and has a low therapeutic index
- used for seizure control, anesthesia induction, and sedation
- end in -ITAL (phenobarbital, pentobarbital, amobarbital, etc)
Barbiturates (Contraindications)
-drug allergy
- pregnancy
- significant respiratory difficulties
- severe kidney or liver disease
- caution in older adults (fall risk)
Barbiturates (drug interactions)
- stimulate the action of enzymes in the liver that are responsible for drug breakdown causing many drugs to be broken down more quickly
- additive effects with alcohol, antihistamines, benzos, opioids
Pentobarbital (Nembutal and phenobarbital
- prototypical barbiturates
- long-acting
- prevention of seizures, rarely used as a sedative, not recommended as a hypnotic
OTC hypnotics
- often contain antihistamines
- Doxylamine (Unisom) and diphenhydramine (Sominex) acetaminophen/diphenhydramine
- use with alcohol can cause respiratory depression or arrest
Muscle Relaxants
- relieve pain by reducing skeletal muscle spasms
- decrease muscle spasticity for disorders such as multiple sclerosis and cerebral palsy
- can cause CNS depression
Muscle Relaxants (Adverse effects)
- euphoria
-lightheadedness
-dizziness - drowsiness
- fatigue
- muscle weakness
Muscle relaxants (interactions/common names)
- any CNS depressants cause interaction: benzo, alcohol
- Common names:
Baclofen (Lioresal)
Cyclobenzaprine (Flexeril)
Dantrolene (Dantrium)
Metaxalone (Skelaxin(
Tizanidine (Zanaflex)
Carisoprodol (Soma)
Chlorozoaxazone (Paraflex)
Methocarbamol (Robaxin)
Nursing Implications
- instruct the patient to not take other CNS depressants
- use caution while driving
- may be habit forming, rebound insomnia may continue for a few nights after discontinued
- assist with ambulation
-monitor for adverse effects and therapeutic effects
