Lecture 2 (Rheum)-Exam 1 Flashcards
Extended-Release Products:
* Who is it reserved for?
* What does it decrease?
* Allow for what?
* What is there a high risk of?
- Reserved for patients with severe chronic pain – usually cancer patients
- Decreased dosing frequency
- Allow for more even steady state with less peaks and troughs
- High risk for overdose of accidently ingested or breach of extended-release mechanism (e.g., crushing, cutting, chewing)
What is a muscle spasm vs muscle spasiticity?
Muscle Spasm
* Sudden / involuntary
* Secondary to fatigue or injury
Muscle Spasticity
* Sustained contraction
* Decreased dexterity from the CNS
* Multiple sclerosis
* Cerebral palsy
* Stroke
* Spinal cord damage
What are approved muscle relaxants for muscle spasms?
- Carisoprodol (Soma)
- Chlorzoxazone (Parafon)
- Cyclobenzaprine (Flexeril)
- Metaxalone (Skelaxin)
- Methocarbamol (Robaxin)
- Orphenadrine (Norflex)
- Tizanidine (Zanaflex)
- Diazepam (Valium)
What are approved muscle relaxants for muscle spasticity?
- Baclofen
- Dantrolene
- Tizanidine
- Diazepam
How does a muscle contract happen?
Action potentials travel down the UMN from the central nervous system
* Cause release of excitatory neurotransmitters (glutamate, norepinephrine)
* Synapse with the LMN
* Activate muscle contraction
What is the inhibitory interneuron?
Regulates excitation of the LMN
Central inhibition of muscle contraction:
* How does Gaba work?
GABA – inhibitory neurotransmitter
* Binds to GABA receptors
* Causes cell hyperpolarization
* Decrease frequency of cell depolarization
* Decreasing muscle contraction
How does Benzodiazepines (diazepam, et al ) work?
- Bind to GABA A receptors
- Increases of Cl- influx
- Hyperpolarization and decreased excitation
Work on CNS
How does baclofen work?
Binds to GABA B receptors
* Postsynaptic – increased K+ efflux
* Hyperpolarization
-
Presynaptic – decrease release of excitatory neurotransmitters (NE and glutamate)
* Less action potentials
Work on CNS
How does Tizanidine work?
- Alpha-2 agonist
- Binds to alpha-2 receptors on presynaptic neurons of the UMN
- Results in less release of exitatory neurotransmitters
Work on CNS
What are the four anti spasticity agents?
Baclofen, dantrolene, diazepam and tizinidine
What is the MOA of baclofen?
Binds GABAb receptors on:
1. LMN increasing K+ efflux, hyperpolarization, decreased action potential
2. Presynaptic UMN inhibiting release of excitatory NT glutamate and norepinephrine
What is the MOA of Dantolene?
Inhibits ryanodine receptors on the skeletal muscle cells; prevents Ca2+ release from SR preventing contraction
WORKS ON SKELETAL MUSCLE SO MORE PNS
What is the MOA of diazepam (Valium)?
Binds BDZ receptor on inhibitory GABAa receptor on LMN; increasing Cl- influx, hyperpolarization, decreased action potentials
What is the MOA Tizanidine (Zanaflex)?
Alpha-2 receptor agonist; binds to presynaptic UMN inhibiting release of excitatory NT glutamate and norepinephrine
What is unique about Dantrolene (Dantrium)?
Hepatotoxicity with high doses
What are the 6 antispasmodics medicine?
- Carisoprodol (soma)
- Chlorzoxazone (parafon)
- Cyclobenzaprine (flexeril)
- Metaxalone (Skelaxin)
- Methocarbamol (Robaxin)
- Orphenadrine (norflex)
What drug is a schedule IV that is antispasmodics?
Carisoprodol (soma)
What are the side effects of central muscle relaxants?
What are the Unique SE of central muscle relaxants?
- Dizziness/ lightheadedness
- Hypotension
- Arrythmias
What are anticholinergic side effects?
- Fever
- Dry mucous membranes
- Flushing
- Blurred vision
- mydriasis
- Hallucinations
- Sedation
- Tachycardia
How are steroids produced?
* Released when?
* What type of effects?
Endogenous steroids produced in the adrenal gland (MC cortisol)
* Released in response to stress and inflammation
* Anti-inflammatory and immunosuppressive effects