Muscle Relaxants and Anesthesia/ Bones and Joints- (WK3- CH11,12,13/ CH22-27) Flashcards
What are the primary mechanisms of aciton of central antispasm drugs ?
most of them are relatively unknown
- flexeril is said to increase serotonin in brainstem and thus inhibit skeletal muscle
- carisoprodil is said to affect GABA-A receptors thus producing sedation similar to diazepam
What is the MOA of diazepam ?
increases the central inhibitory effects of GABA and increases that GABA-induced inhibition at the synapse.
- attaches to GABA receptors and prevents Cl channels from functioning; thus limiting excitability of tissues
What are the main adverse effects of valium/diazepam ?
may produce sedation, and a general reduction in psychomotor ability; can produce tolerance and physical dependence; sudden withdrawal can cause seizures, anxiety, agitation, tachycardia, and death.
What is the MOA of baclofen ?
-baclofen is synthetic GABA, and stimulates the effects of GABBA on GABBA-B receptors; has an inhibitory effect on alpha motor neuron activity within the spinal cord, occurs by inhibiting excitatory neurons that synapse with the alpha motor neuron and by directly affecting the alpha motor neuron.
can be administered intrathecally
What are the signs and symptoms of a baclofen overdose and withdrawal ?
OD: decreased respiration; decreased cardiac function; stupor, coma
withdrawal: fever, confusion, hallucinations, seizures
What is the MOA of dantrelene sodium and adverse effects ?
-direct muscle relaxant, inhibits release of Ca++ from skeletal muscle sarcoplasmic reticulum.
-adverse effects include muscle weakness, may cause severe hepato-toxcity.
What is the MOA of alpha-2 agonists ( Tizanidine ) ?
- acts by selectively binding to alpha 2 receptors in the CNS, binding to spinal cord inter-neurons that excite muscle tissue. stimulation of alpha 2 receptors inhibits the firing of interneurons that relay information to alpha motor neurons.
What are the adverse effects of alpha-2 agonists/ Tizanidine ?
sedation, dizziness, dry mouth
-may be a better alternative to diazepam and oral baclofen
What is the MOA of botulinum toxin ? adverse effects ?
-muscle paralytic that acts by inhibiting ACh release at skeletal NMJ
- overdose symptoms include drooping eyes, dysphagia, dysphonia, muscle weakness, and respiratory distress; since botox is a toxin
osteoporosis is primarly found in:
post-menopausal women of white and asian race
Define osteogenesis imperfecta:
-the abnormal formation of type I collagen caused by a genetic disorder leading to bone bowing and multiple fractures
Intrathecal administration of baclofen typically refers to drug delivery into:
the subarachnoid space
Muscle relaxant effects of botulinum toxin appear to diminish or wear off after several months because:
a new presynaptic terminal sprouts from the axon that was originally affected by the toxin
What are the three different kinds of fractures ?
sudden impact/trauma, stress or fatigue fracture, pathological fracture
What are the three phases of healing in order ?
Inflammation, Reparative, Remodeling
