What are the two general types of musculoskeletal relaxants?
centrally acting skeletal muscle relaxants and direct acting skeletal muscle relaxants
How do centrally acting skeletal muscle relaxants work?
they depress the CNS like sedatives, have no direct action on the muscles, enhance GABA inhibitory effects in the cord
What two things can muscle relaxants be used to treat?
chronic debilitating disorders (e.g. MS, strokes, cerebral palsy, etc), spasms from muscle injury
What are some chronic debilitating disorders that muscle relaxants can be used to treat?
MS, strokes, cerebral palsy, head injuries
What are the common side effects of all muscle relaxants? What two systems do they generally affect?
drowsiness, dizziness, lightheadedness, N/V/D, abdominal distress. CNS and GI side effects.
Why would a person on a muscle relaxant have GI side effects?
because the muscle relaxant will "sedate" the muscles
What two types of muscle relaxants can cause anticholingergic side effects?
Cyclobenzaprine and orphenadrine (Norflex)
What is the most effective centrally acting muscle relaxant? Why it that?
Baclofen (Lioresal). it is VERY similar to GABA
Baclofen (Lioresal) relieves muscle spasms in _____ and _____ _____ _____.
MS and spinal cord lesions
What is an example of a muscle relaxant that is direct acting? What is it used to treat spasms in?
Dantrolene (Dantrium). spinal cord injury, stroke, MS, CP
How does Dantrolene (Dantrium), a direct acting muscle relaxant, work?
decreases calcium release from the sarcoplasmic reticulum in muscle cells
What is a muscle relaxant used to manage spasticity in spinal cord injury and MS?
What can Diazepam (Valium) be used to treat? What is its therapeutic class?
anxiolytic and anticonvulsant. relieves muscle spasms in paraplegia and CP.
What are two muscle relaxants that are used for acute/severe/short-term treatment? Are they centrally acting or direct acting?
Cyclobenzaprine HCl (Flexeril), Methocarbamol (Robaxin). centrally-acting
What are depolarizing muscle relaxants used in adjunct to? What are they also referred to as? What do they induce? What are they NOT used for? What are some examples of drugs that fall into this category?
anesthesia. neuromuscular blockers. skeletal muscle relaxation. NOT used for spasticity. Pavulon, Vecuronium, Succinylcholine.
What is a unique route for Baclofen? What is this used for and when especially would it be used? What is a special consideration for this though that the patient must meet?
baclofen pump, intrathecal (into CSF). used with spasticity or dystonia when the patient is having excessive problems with daily cares, bathing and/or pain. the patient must have a big enough body to hold the pump which is placed in their abdominal SQ tissue.
What are the two types of CNS depressants? What is the difference between them? What does the classification one way or the other depend on?
sedatives and hypnotics. a sedative will relax the person but a hypnotic will put them to sleep. the degree to which the drug inhibits transmission of nerve impulses to the CNS.
Central nervous system depressants work to potentiate what neurotransmitter?
the inhibitory neurotransmitter, GABA
What are sedatives also called? What three things do they help to reduce? What do they NOT cause? What can they become if the dose is too high?
anxiolytics. nervousness, excitability, irritability. don't cause sleep. hypnotic
What are the three main groups of central nervous system depressants?
barbituates, benzodiazepines and miscellaneous
What are side effects/adverse reactions common in ALL central nervous system depressants?
hangover, REM rebound (hypnotics), dependence, tolerance, excessive depression, respiratory depression, hypersensitivity
What is the REM rebound that may occur with hypnotics?
vivid dreaming when the hypnotic is stopped after prolonged use
What does the tolerance associated with sedatives and hypnotics mean for dosing?
the dose must be increased over time to obtain the desired effect
What is an example of an ultra-short barbituate? What is it used for?
thiopental (Pentothal). general anesthesia
What are some examples of short-acting barbituates? (2) What are they used for?
Pentobarbital (Nembutal), Secobarbital (Seconal). used to induce sleep
What are some examples of intermediate-acting barbituates? (3) What are they used for?
Amobarbital (Amytal), Aprobarbital (Alurate), Butabarbital (Butisol). used to sustain sleep
What is an example of a long-acting barbituate? What is it used for?
phenobarbital (Luminal). seizures
What class of controlled substance are barbituates? What are some characteristics of this class?
Class II. high abuse potential but still accepted medical use. few are used today. habit forming and have a low therapeutic index.
What controlled substance class are benzodiazepines? What are some characteristics of this class?
class IV. less abuse potential than class III. accepted medical use. limited physical and psychological dependency.
What selected benzodiazepines are used for sleep, or as hypnotics?
Flurazepam (Dalmane), Temazepam (Restoril), Triazolam (Halcion).
While benzodiazepines are very safe if taken alone, what are some of their drug-drug interactions?
alcohol, antidepressants, narcotics
What is a benzodiazepine that is used for procedures? What purpose does it serve? What types of procedures is it used with?
Midazolam (Versed). anxiolytic and to cause amnesia. those that require conscious sedation.