Pharmacology of Centrally-Acting Skeletal Muscle Relaxants Flashcards
How do centrally-acting skeletal muscle relaxants decrease symptoms of spasticity?
Decrease the hyperactive reflex arc, interfere with skeletal muscle, enhance the action of inhibitory interneurons
What is the MOA of diazepam?
Binds to GABAa receptors to enhance Cl- channels and cause hyperpolarization
What benzodiazepine is best used in patients with poor liver function?
Oxazepam
What are the disadvantages of benzodiazepines?
Potential for dependence, anterograde amnesia
What drug reverses the actions of benzodiazepines?
Flumazenil
What drug is a benzodiazepine derivate used to treat spasms not responsive to other drugs?
Baclofen
What is the MOA of Baclofen?
Binds GABAb receptors to increase K+ efflux and cause hyperpolarization
What is the MOA of Gabapentin?
Decreases Ca2+ entry to reduce glutamate release
What drug is used to treat patients with ALS?
Riluzole
What is the MOA of Tizanidine?
Binds a2 receptors to inhibit neuronal transmission
Tizanidine is similar to diazepam, with the exception of their ADRs. What ADRs are associated with tizanidine?
Drowsiness, hypotension, dry mouth, asthenia (weakness)
What is the MOA of dantrolene?
Dantrolene is a direct-acting relaxant. It decreases Ca2+ by binding to ryanodine receptors
Malignant hypertension may be treated with which skeletal muscle relaxant?
Dantrolene
What is the MOA of botulinum toxin?
Blocks ACh vesicle release
Drugs treating muscle spasms act primarily where?
At the brainstem
