CNS, A2 agonists, Opioids Flashcards
What drug is used to treat malignant hyperthermia?
Dantrolene
- inhibits Ca2+ release from SER to cause muslce relaxation, does not generally affect respiratory muscles significantly.
Which species is susceptible to Malignant hyperthermia?
Pigs- Belgian landrace
Dogs- Greyhounds
What triggers Malignant hyperthermia? Name some clinical signs?
Halothane
- rapid sustained rise in body temp
- tachycardia, cyanosis, generalized muscle rigidity, cardiac arrhythmias are common clinical signs
- Acidosis, hyperkalemia, hyperphosphatemia, hypocalcemia from muscle-cell breakdown
- RHABDOMYOLYSIS
- Renal failure, DIC
Name some centrally acting muscle relaxants?
Opioid agonists, Alpha 2 agonists, GABA agonists, General anesthetics.
- Guaifenesin (GG, GGE, Guailaxin)- Equines and cattle
- Methocarbamol (Robaxin-V) (dogs, catas, horses) oral or injectable.
Guaifenesin is used at what percentage and why? What is the target and the duration of onset?
5% for IV infusion Because thrombophlebitis can be seen with over 10% and hemolysis can also be seen with even more than 10%. Cattle are more sensitive to this than horses.
- Depresses the nerve impulse at the internuncial neuron in the spinal cord
- Rapid onset at 2 mins and short duration 10-20 mins
Clinical use of Guaifenesin
Anesthetic protocol to facilitate intubation, smooth anesthetic induction and recovery, and for anesthetic sparing effect
What is in the triple drip?
GG + Alpha 2 agonist + ketamine
Cautions with Guaifenesin?
Contraindicated use of physostigmine. Be cautious with other cholinesterase inhibitors neostigmine and edrophonium
Methocarbamol is not typically used in anesthesia like GG, what is it typically used for?
Reduce muscle spasms.
- Supportive therapy for tremorgenic toxicoses like pyrethrins or strychnine. Urethral obstruction.
Def of Tranquilizer
Neuroleptic, anxiolytic
patient relaxed aware of their surroundings
Sedative definition
Induces a state characterized by CNS depression and drowsiness decreased awareness
Hypnotic def?
SLEEP
Narcotic?
Stupor bordering on general anesthesia. OPIUM.
Local regional anesthesia definition
loss of sensation in a circumscribed body area
General anesthesia definition?
drug induced unconsciousness characterized by controlled, reversible, depression of the CNS and analgesia. sensory, motor and autonomic reflexes are reduced
Typically lipophilic drugs cross the BBB. T/F
True
Ascending reticular activating system is involved in?
Consciousness
Name excitatory receptors that when are suppressed cause depression of the CNS
Glutamate stimulated the NMDA receptor
ACH - neuronal nicotinic receptors
5HT3 seratonin- stimulates 5 HT receptors
Which receptors can be mimicked to depress the CNS?
GABA
Glycine
Surgery requires which of the following?
- Reduced consciousness
- Muscle relaxation
- Analgesia
- All of these?
- Only Muscle relaxation and Analgesia
All of them!
Pheothiazines used primarily for ?
Sedation
Drugs in the Phenothiazine class work on which receptors?
Dopamine receptor antagonists.
antagonism at histamine and muscarinic receptors
Phenothiazines can be given A. IV B. IM C. SQ D. PO E. A and D F. All of them
All of them
Pharmacologic effect of phenothiazine at the
CNS, ANS, Cardio, Resp., Skeletal, Analgesia?
CNS- Sedation, anti-emesis
ANS- Vasodilation => hypotension.
Cardio - Hypotension mostly with Acepromazine, bradycardia, boxers sensitive to Ace
Respiratory- at high doses respiratory depression
Skeletal? Moderate muscle relaxation
Analgesia? NONE IMPORTANT
Acepromazine is a Phenothiazine, but does it provide analgesia? Give me an adverse effect?
NOPE! Just Sedation. Hypotension! Boxers particularly sensitive to the cardio effects of ace. MDR1 ABC1 gene mutation dogs may have longer duration, careful with Stallions and their giant penis (paraphimosis predisposing to penile injury). AGRESSION. Extrapyramidal signs.
What are extrapyramidal signs?
Extrapyramidal system consists of axons that do not pass through the pyramidal system which initiates voluntary, discrete and learned movements. Extrapyramidal system is more responsible for postural antigravity muscle tone to keep you upright. Proximal extensor muscles. So the signs are stiffness, tremor, motor restlessness, tightening of facial muscles and opisthotonos (severe extensor rigidity)
Is Ace contraindicated in patients with seizures?
Nope… matter of opinion.. but it says on the label to not use in seizure patients.
Butyrophenones used as ____________ in human med. Not used in VET MED
antipsychotics
its a phenothiazine
Azaperone is used primarily in which species and for what?
Swine, reduces aggression
BAM is what?
Butorphanol-azaperone-medetomidine used for darting wild ungulates
Haloperidol is used to control feather picking behavior in birds? T/F
True
Benzodiazepines provide reliable sedation when alone in ruminants T/F?
True
But not typical with other species. Good muscle relaxants and anti seizure activity
What is the MOA with Benzodiazepines?
Potentiate GABA receptors
When you say GABA think INHIBITION
Should diazepam be given IM?
Nope cause pain because the 40% propylene glycol.
Which benzodiazepine can be given IM?
Midazolam
Can cats be given oral diazepam? What about injectable?
NOPE. causes hepatic necrosis when given orally, you can still give it injectable
Which benzodiazepines gives the longest duration?
A. alprazolam
B. diazepam
C. Lorazepam
D. A and C
D.
Pharmacologic actions of Benzodiazepines
CNS: Mild sedation, Sedative-hypnotic effects
Good Skeletal muscle relaxation
Anticonvulsant
Aggression and Excitement in dogs,cats, horses, used with opioids, ketamine or tiletamine
Cardio: Minimal cardiac and respiratory effects seen at therapeutic doses, depression at larger doses
NO ANALGESIA
Diazepam is used in anesthetic premed, anticonvulsant and appetite stimulant?
YAsss
Not for chronic anti seizure
good for geriatric patients
given rectally (transmucosal absorption) in emergencies
AVOID ORAL DIAZEPAM IN CATS