Muscle Relaxants and AEDs Flashcards
What are the anti-tremorogenic and sedating drugs
Methocarbamol
Guaifenasin
Dantrolene
What re the antiepilieptic drugs
Diazepam and midazolam Phenobarbital Bromide Levetricetam Zonisamide
What is the site of action of dantrolene?
Peripheral -muscle cells
What is the site of action of guaifensin?
Central -> spinal cord
What is the site of action of methocarbamol
Central -> spinal cord
What is the MOA of dantrolene?
Peripherally acting muscle relaxant -> acts on the muscle cell
T/F: dantrolene crosses the BBB
F
What is the drug of choice for treatment of malignant hyperthermia (hypermetabolic syndrome)
Dantrolene
What is hypermetabolic syndrome
Idiosyncratic drug reaction
Hyper metabolic rxn on skeletal muscle -> rhabdomyolysis
Life threatening hyperthermia, hyperkalemia, and cell death
Multiple organ dysfunction syndrome (MODS)
Often fatal
__________ are very toxic to dogs and can lead to malignant hyperthermia
Hops
What are the clinical uses of dantrolene
Malignant hyperthermia
Tetanus –> cause muscle relaxation
What is the MOA of methocarbamol?
Blockade of nerve impulse transmission in the spinal cord
Cross the BBB
What is the main clinical use of methocarbamol?
Reduce muscle spasm (approved in cat, dog, and horse)
- > tetanus
- > intoxication (tremorogenic)
Treatment of acute inflammatory or traumatic conditions (eg intervertebral disk disease )
Functional urethral obstruction/urinary retention (less common use)
What is the half life of methocarbamol
Relatively short (1-2hrs) Shorter when given IV
How is methocarbamol administered
Oral or IV
Irritating if administered IM/SQ -> not recommended
Strychnine, metaldehyde, pyrethrin(cat) and some toxic molds are treated with ____________ to reduce treorogenic toxins
Methocarbamol
What are the side effects of methocarbamol ?
Sedation, salivation, weakness, lethargy, and ataxia
Caution using injectable form with renal disease
Avoid extravasation and administer IV slowly
What is the MOA of Guaifensin
Centrally-acting muscle relaxant and expectorant (break up a cough)
Blocks nerve impulse transmission in spinal cord, brain stem and subcortical areas of the brain -> cross BBB
What is the onset and duration of guaifensin
Rapid onset and short duration (10-20min)
What are the clinical uses of guaifensin ?
Intubation -> relax pharyngeal and laryngeal muscles
Procedural sedation in horse and cattle
-> Guaifensin + Xylazine + ketamine (triple drip)
What are precautions to using guaifensin
High concentration causes hemolysis
Cattle more sensitive than horse
______________ drug is contraindicated in horse receiving guaifensin
Physostigmine
________ is a clinical manifestation of abnormal electrical activity in the brain (uncontrolled firing of neurons)
Seizure
_________ is a chronic syndrome of seizures occurring intermittently over months to years
Epilepsy
__________________ is ‘true epilespy’ and is genetic
Idiopathic
______________ epilepsy has intracranial vs extra-cranial causes
Acquired/symptomatic
________________ seizures is when more than one seizure occurs within a 24hr period with recovery inbetween
Cluster
____________________ is when you have repeated seizures without full recovery between them or a single seizure that lasts > 5mins
Status epilepticus (SE)
_____________ drugs prevent or treat seizures
Anticonvulsants
_______________ drugs generally refers to maintenance management of epileptic seizures
Antiepileptic drugs (AED)
_____________ seizures do not respond to therapeutic doses of AEDs
Refractory
_______________ seizures occur at periodic intervals during treatment course with AEDs
Breakthough
What are the types of seizures
Generalized
- convulse
- non-convulsive (absent)
Partial
- simple (lateralizing motor activity, no loss of consciousness)
- complex (altered motor activity and consciousness)
What is the major excitatory neurotransmitter in the brain?
Glutamate -> depolarization
-interact with NMDA, AMPA and kainate receptors
What is the major inhibitory neurotransmitter in the brain
GABA (hyperpolarization)
-interact with GABA receptor (Gprotein coupled)