Flashcards in Review Questions Exam 3 Deck (36):
_________ is a common source of theobromine poisoning.
This drug is used to stimulate post anesthesia respiration
T or F : Methyxanthines act by stimulating adenosine receptors
_______ is the region of the brain that acts as a relay center
Dopaminergic cell bodies are located in ______ and ______ regions of the brain
ventral tegumental area, substantia nigra
What is the class of behavior modifying drugs that works by enhancing GABAnergic neurotransmission?
______ is an anxiolytic that is non sedating and works by activating 5-HT 1A and D2 receptor
What class of drugs works by selectively inhibiting 5-HT re-uptake? What is the therapeutic advantages associated with long term use of the drug?
Serotonin Selective Reuptake Inhibitors (SSRIs).
Therapeutic advantages associated with long term use of the drug includes
not cardio toxic, non sedating, do not impari learning,
side effects uncommon
TCAs work by _____. List the side effects associated with long term use of the drug.
block reuptake of NE and 5-HT to a lesser degree, produces desensitization of α-2 adrenergic receptors and 5-HT autoreceptors resulting in elevated extrasynaptic levels of 5-HT and NE, and also serves as blockade of muscarinic receptors responsible for its anticholinergic side effects
________ class of drugs work by inhibiting MAO. List the therapeutic uses of the drug.
Define a Tranquilizer? Do they (Phenothiazine and Butyrophenone) posses inherent analgesic effects?
NO they do not have any analgesic effects
Tranquilizer - neuroleptic, anxiety reduced w/o loss of consciousness, depresses teh hypothalamus and reticualr formation function
Are the adverse effects of Phenothiazine reversible?
NO reveral agent
What are butyrophenones most commonly used for?
sedative, pre anesthesia, potent antiemtic
What is the mechanism of action of Phenothiazines?
blockade of post synaptic dopaminergic receptors- D2 antagonist, results in vasodialtion
Describe the mechanisms underlying cardiovascular side effects of phenothiazines?
Pheno- main effect is alpha 1 antagonist resulting in peripheral vasodialtion
baroreceptors interpret this as hypovolemia; reflex tachycardia resutls
AVOID in hypovolemic animals
Can phenothiazines be administered to animals undergoing skin testing?
it can, but you shouldn't , act as H1 histaminergic antagonist
What are the effects of phenothiazines on seizures?
blockage of RAS, decreased spontaneous motor fx, dampens motor function
List the therapeutic uses of phenothiazines
tranquilization- calms the animal and facilitates physical exam/diagnostic procedures
used as pre-anesthetic in general anesthesia, allows dose reduction and amelioration of adverse effects associated with some agents
antiemetic effect in dogs but not cats
Which lasts longer for xylazine: the analgesia or sedation?
What is the net result of alpha 2 adrenergic receptor activation?
Decrease in sympathetic outflow resulting in decreased circulating levels of catecholamines
The sedative effects associated with xylazine are related to activation of adrenergic receptors in__________ located in _____________.
locus coeruleus, pons and lower brain stem
Provide the rank order of species responsiveness in regards to xylazine’s sedative effects
RMT > cats and dogs > pigs (least)
The skeletal muscle relaxation effects of xylazine are related to inhibition of ___________.
interneuronal transmission in the spinal cord
Describe the cardiovascular effects of xylazine
bi-phasic response with phase 2 being further perpetrated by central sedative effects and reduced sympathetic tone.
Phase 1: activation of peripheral alpha 2 receptors accounts for the rapid increase in systemic vascular resistance which is clinically identified as an increase in arterial BP - transient process= short duration
Phase 2: Hypertension induces a reflex-baroreceptor mediated physiologic bradycardia, associated with bradyarrythmias and decreased CO.
Xylazine produces emesis most frequently in this species
Name a potent alpha 2 agonist you studied in class that can cause ataxia in horses?
Medetomidine in high doses
Can Xylazine be given to cattle in the last trimester?
NO should not because increases the risk of premature parturition
oxytocin like effect
Define a seizure and its four components
seizure- rapid synchronous, uncontrolled spread of electrical activity; rhythmic firing of if a group of neurons
Prodrome- behavioral changes, that occur days, or hours before
Aura- event characterized by sensory and psycho-sensory symptoms in humans "something is wrong"
Ictus- seizure event
Post-ictal phase- behavior changes, that occur days/hours after
An adverse effect that is most common to benzodiazepine anticonvulsants in cats is_________
What are the two major medical emergencies related to seizure disorders?
Identify the type of seizure where structural lesions in the brain may be a predisposing factor for seizure development
List the characteristics of a simple and complex partial seizure
simple- no loss of consciousness, abnormal firing, focus located in the motor portion of cerebral hemisphere
complex- altered consciousness, exhibit repetitive behaviors, abnormal behavior (staring into space, maniac dogs) temporal lobe, likely to evolve into generalized seizure
What is the other name for generalized seizures and list its characteristics?
grand mal seizure
most common in animals; brain regions diffusely affected-> more damage
abrupt loss of consciousness
What is the mechanism of action of phenytoin?
prolongs the refractory period of voltage gated sodium gated channels
stabilizes the membrane
List the names of drugs that elicit their anti-convulsant effects by potentiating GABA neurotransmission