Final Flashcards
Term for hormone like substances that are synthesized and fxn in a localized area.
Autacoids
What are the 2 biogenic amines?
histamine and serotonin
What autacoids are polypeptides?
angiotensin and kinins
Term for histamine release caused by things other than IgE?
anaphylactoid
What are the 3 main causes of histamine release?
local injury, immune mediated, drugs, etc
What is the role of the H1 receptor?
smooth muscle contraction, vascular dilation and permeability, sedation
What is the role of the H2 receptor?
gastric acid and pepsin secretion, vasodilation
What is the “triple response” of histamine intradermally?
redness, flare, wheal
What is the MOA of first and second generation anti-histamines?
reversible competitive inhibitors of histamine
What are the other receptors first generation antihistamines act on?
antimuscarinic, alpha adrenergic
What is a potent antagonist of serotonin?
cyproheptadine
What generation of anti histamines penetrate BBB?
first gen
What is the primary and secondary tx of systemic anaphylaxis?
primary - epinephrine
secondary - antihistamines
What are the 4 H2 receptor antagonists (systemic antacids)?
cimetidine, ranitidine, famotidine, nizatidine
What H2 antagonist is a potent CYP450 inducer?
cimetidine
What drug stabalizess membrane and prevents release of histamine from mast cells?
cromolyn sodium
What 2 cells store pre-made histamine in the body?
mast cells - tissue
basophils - blood
What 2 tissues continually synthesize histamine?
GI tract (enterochromaffin like cells of stomach)
CNS (axons)
(both are non mast cell pool)
Where is serotonin produced and stored in the body?
GI tract - enterochromaffin cells (90%)
CNS
Blood - stored in platelets
What are the physio effects of serotonin in muscles?
contracts non vascular smooth muscle (uterine, gastric, intestinal, bronchial)
What are the 5 effects of serotonin in the body?
- contract non vascular smooth muscle
- Emesis (via CRTZ)
- stimulates nerve endings
- regulates behavior
- local vasoconstriction and hemostasis
What serotonin antagonist is an appetite stimulant in cats only?
cyproheptadine
What serotonin agonist is used in tx of gastric empyting disorders and other motility disorders?
cisapride
What are the 3 5-HT3 receptor antagonists that are used for cancer chemo induced emesis?
ondansetron, dolasetron, ganesetron
What are examples of selevtive serotonin reuptake inhibitors?
fluoxetine, paroxetine, sertraline, fluvoxamine, nefazodone
What are the MOA of TCAs like clomipramine, amitriptyline, desipramine, doxepin, imipramine?
block reuptake of norepinephrine and serotonin
What are the 2 common mechanisms of ectopic dysrhythmias?
reentry phenomenon
enhanced automaticity
What are examples of selevtive serotonin reuptake inhibitors?
fluoxetine, paroxetine, sertraline, fluvoxamine, nefazodone
What are the MOA of TCAs like clomipramine, amitriptyline, desipramine, doxepin, imipramine?
block reuptake of norepinephrine and serotonin
What are the 2 common mechanisms of ectopic dysrhythmias?
reentry phenomenon (piece is damaged) enhanced automaticity
What is the goal of treating supraventricular arrythmias?
control conduction velocity through AV node
What is the goal of tx ventricular arrythmias?
decrease excitability
What is the goal of tx of re-entry arrythmias?
decrease conduction velocity or prolong refractory period
What is the goal of tx of all arrythmias?
decrease excitability by sympathetic outflow, correct electrolytes
What are the 4 classes of antidysrhythmic drugs and their MOA?
class 1 - NA channel blocker Class 2 - beta blocker class 3 - K channel blocker class 4 - calcium channel blocker
What is the main usage of quinidine in VM? What else does it treat?
atrial fibrillation in horses
txs acute and chronic supraventricular dysrhythmias
What are the two class 1a antiarrythmic drugs?
Procainamide and quinidine
What are the 3 different subclasses of class 1 antiarrythmic drugs? What effect do they have on refractory period?
1a - lengthen AP and refractory period
1b - shorten AP and refractory period
1c - decrease rate of phase 0 depolarization
What are the 2 class 1b antiarrythmic drugs?
lidocaine, mexiletine
What arrythmias does lidocaine treat?
acute control of ventricular dysrhythmias
What drug can be used long term is and called “oral lidocaine”?
mexiletine
What beta blocker is non-selective?
propranolol
What are the 3 clinical inications of beta blockers as anti-arrythmics?
rate control of supraventricular and ventricular tachyarrythmias
excessive sympathetic tone (hyperthyroid)
anti-hypertension
What is the half life order of the 3 beta blockers?
atenolol>propranolol>esmolol
What are the 3 adverse effects of beta blockers?
exacerbation of HF or nodal dysfunction
bronchoconstriction
prevention of glycogenolysis (not good in diabetes)
What is the MOA of class III antiarrythmic drugs?
decrease proportion of cardiac cycle where muscle is excitable (prolong cardiac depolarization and refractory period of muscle)
What anti-arrythmic drug has a wide spectrum of activity on refractory supra and ventricular tachydysrhytmias?
amiodarone
What is sotalol used for?
sustained ventricular tachycardia, ventricular or atrial fibrillation (non selective B blocker at lower doses)
What are the 2 adverse effects of sotalol?
mild negative inotrophy (caution CHF)
exacerbate nodal dysfunction (beta blocker)
What is the MOA of class IV anti arrythmic drugs?
inhibit L type calcium channels - decrease slow inward current
What drug is used to control hypertrophic cardiomyopathy in cats and supraventricular tachyarrythmias?
diltazem
What 2 drugs are Class IV anti arrythmic drugs?
diltiazem
verpamil (more potent)
What are the 3 drugs used for acute tx of VPCs or V tachs?
lidocaine
procainamide
esmolol
What are the 4 drugs used for acute tx of supraventricular arrythmias?
procainamide
diltiazem
esmolol
lidocaine?
What are the 2 drugs used for acute tx of combined supraventricular and ventricular tachydysrhtymias?
procainamide
esmolol
What is the preferred cox2/cox1 ratio for an NSAID?
less than 1 = more specific for cox2
What are the 5 main pharmacological actions of NSAIDs?
antipyretic
anti-inflammatory
analgesic (NOT severe visceral pain and broken bones)
anti-platelets
What 2 NSAIDs have improved absorption when given with food?
tepoxalin and deracoxib
Are NSAIDs weak acids or bases?
weak acids (well absorbed from stomach)
What is the Vd of NSAIDs?
small –> binds to albumin (caution in dehydrated animals)
What are the 7 shared SE of NSAIDs?
GI ulceration protein losing enteropathy CNS despression Sodium and fluid retention renal damage increase bleeding time hepatotoxicty
What 4 drug classes do NSAIDs interact with?
Fursomide (diminishes CV effects)
ACE inhibitors
Fluoroquinolones (seizures)
Antacids (interefere with absorption)
What are the 3 therapeutic uses of NSAIDs?
musculoskeletal disorders
spetic and endotoxic shock
pain and inflammation
What is the difference of effect of acetaminophen versus other NSAIDs?
no anti-inflammatory and antiplatelet activities
What does acetominophen toxicity cause in cats? dogs?
cats - heinz body anemia
dogs - hepatotoxicity
What is the antidote of acetominophen?
N-acetylcysteine
What NSAID is used for soft tissue problems in horses?
naproxen
What NSAID is used for musculoskeltal disorders, visceral pain, and inflammation in horses and also helps in cattle with respiratory dz and endotoxemia?
flunixin meglumine
What is the most commonly used NSAID and is approved for dogs and horses but banned in food animals?
phenylbutazone ( should be avoided in dogs - better drugs)
What drug do some consider the NSAID of choice for cats?
ketoprofen
What are the 2 bad side effects of meloxicam in cats?
acute renal failure and death
What drug inhibits both cyclooxygenases and 5-lipoxygenase enzyme activities?
tepoxalin
What species is etodolac approved for?
dogs only (do not use in cats!)
What NSAID is approved to be used topically in horses and also as a opthalmic drug?
diclofenac sodium
What NSAID is both antiinflammatory and antitumor (indirect)? Used for transitional cell carcinomas of the bladder.
piroxicam
What human approved NSAID is being used in cats for feline asthma and in dogs fo atopic dermatitis?
zafilukast
What NSAID doesnt inhibit COX, but instead traps superoxide radicals?
orgotein
What are the two uses for orgotein?
horses - soft tissue inflammation
dogs - spondylitic syndromes or vertebral dz
What NSAID can penetrate all biological membranes and is a solvent?
DMSO, dimethyl sulfoxide
What do glucosamine and chondroitin sulfate work synergistically to do?
inhibit cartilage breakdown
What are the 4 effects of hyaluronic acid intra articulary?
joint lube, shock absorbtion, anti inflammatory, nutrition for cartilage
What effects do glucocorticoids have on water balance?
inhibit ADH, increase ECF and GFR
What effects do glucocorticoids have on the CV system?
+ chrono and inotropic, sensitize to catecholamines
What 3 things does the “steroid” base of the glucocorticoid determine?
potency of antiinflammatory and mineralcorticoids
duraction of action at specific site
What is the potency hierarhy of “soft” glucocorticoids?
fluticasone>belcomethasone == budesonide
Term for alkaloids derived from opium including morphine and codeine.
opiates
Term for all naturally occuring and synthetic compounds that act on opiod receptors.
opiods
What are the 3 opiod receptors?
mu, kappa,, delta
What are the effects of the MOP receptor?
analgesia, sedation, euphoria, resp depression, g.i. stimulation, physical dependence
What are the effects of the KOP receptor?
antitussive, spinal analgesia, sedation, miosis, g.i. stimulation, increased appetite
What are the effects of the DOP receptor?
analgesia, emotion, increased appetite
What is the general MOA of opiod receptors?
inhibit release of excitatory transmitters from small diameter primary afferent fibers (C and fine myelinated A fibers)
Whare are Mu receptors located?
peripheral and supraspinal
Where are Kappa receptors located?
spinal
Where are delta receptors located?
spinal and supraspinal
What is the origin of endogenous opiod peptides?
cleavage of POMC
What are the three endogenous opiods?
B-endorphin, met-enkephalin, Dynorphin A
What pain pathways do opiods activate/inhibit?
activate descending pathways that inhibit primary afferents presynaptically and inhibit STT cells postsynaptically
What is the MOA of opiods?
Gi and Gq –> inhibit adenyl cyclase –> hyperpolarization
What effect do opiods have on GABA receptors?
inhibit GABA which allows dopamine to have positive effect on inhibitory neurons
What opiod receptor is responsible for dysphoria?
KOP
What two opiod receptors have GI effects that include induction of emesis and constipation?
MOP and KOP
What opiod receptor has “ceiling effect” on respiratory depression and doesnt cause death?
KOP
What are the non lethal side effects of opiods?
emesis, constipation, inhibition of gastric, pancreatic, and biliary excretion, urinary retention, hypotension, changes in pupillary diameter, changes in body temp, increased intracranial pressure
What species do opiods cause hypothermia?
rabbits and dogs (others -> hyperthermia)
What species do opiods reduce the pupillary size?
miosis - dogs, humans, rabbits
others - mydraisis
How is tolerance developed in opiods?
inhibits AC –> AC expression increases –>cesation leads to high cAMP levels
What is the prototype of a full mu receptor agonist? partial mu receptor agonist?
full - morphine
partial agonist - codeine
What is the prototype drug of a opiod mixed agonist-antagonist? antagonist only?
mixed - butorphanol
antagonist - naloxone
What are the MOAs of tramadol?
weak partial MOP agonist but also interacts with KOP and DOP receptors
also weak inhibitor of NE and 5-HT uptake
What is the cause of the wide variation of effects of tramadol?
active metabolite M1 –> individual varied production
What are the 4 clinical analgesic applications of opiods?
analgesia, neuroleptanalgesia, spinal analgesia, preanesthetic
What are the 4 clinical uses of opiods that do not have to do with pain?
antitussives, emetics, antispasmodics, immobilization
Term for when a opiod antagonist wears off before agonist.
renarcotization
Which opiod receptor is most susceptible to antagonism?
MOP
What schedule drug is morphine?
2
What schedule drug is hydrocodone?
3
What schedule drug is propoxyphene? diphenoxylate?
prop- 4
diphen - 5
What is the difference between a gas and a vapor?
gas - at proper temp and pressure
vapor - gaseous state of material below boiling point
What is vapor pressure?
pressure = force/area
What is STP?
standard temp pressure?
0 degrees C, 760 mmHg
How does partial pressure differ from volume %?
partial pressure = # of molecules
volume % = number of molecules as it relates to total number of molecule present
Will the partial pressure of a gas be higher or lower at high altitude compared to sea level?
same but volume % will be higher (less molecules at higher altitudes)
What is daltons law?
mixture of gases exerts same pressure if it were alone (additive)
Term for the temperature above which a substance cannot be liquefied?
critical temp
What are partition coefficients?
related to solubility of an agent in different media
What are biological properties of an ideal anesthetic agent?
low blood:gas solubility high oil:gas solubility minimal SE no biotransformation non toxic
What are the 3 inflow factors for anesthesia?
increase minute ventilation
oxygen flow rates
inspired anesthetic concentration (turn up vaporizer)
What are the 3 outflow factors for anesthesia?
solubility
cardiac output
alveolar to venous anesthetic gradient
How can the inspired anesthetic concentration be increased?
splitting ratio - increasing concentration in circuit increases alveolar partial pressure
Will a high or low B:G partition give longer induction times?
the higher the B:G = long induction
What is the hierarchy of B:G partitions?
Halothane>isoflurane> sevoflurane
Will a high or low cardiac output prolong induction time?
high CO = long induction time
What 3 things affect the elimination of anesthetic via lungs?
increased minute ventilation
increased CO
solubility
(different from outflow factors….alveolar to venous anesthetic gradient instead of ventilation)
Definition of MAC.
amount (%) at 1 atm required to prevent movement in 50% of population
What MAC produces surgical anesthesia?
MACx1.3 to 1.5
What are the MACs of Isoflurane for dog, cat, and horse?
dog - 1.3
cat - 1.6
horse - 1.3
What are the MACs of Sevoflurane for dog, cat, horse?
dog - 2.4
cat - 2.6
horse - 2.3
What are some physio factors that decrease the MAC?
ACIDOSIS, hypoxia, induced hypotension, hypothermia, pregnancy, opiods, acepromazine
What are some physio factors that increase the MAC?
duration of anesthesia, alkalosis, hyperoxia, thyroid, hyperkalemia, naloxone
What are the effects of inhalent anesthetics on the CNS?
decrease in oxygen req
effect on cerebral blood flow autoregulation
What are the SE of inhalents on the CV system?
myocardial depression
vasodilation
sympathomimitis (NO only)
What are the two biggest concerns of side effects in inhalent anesthetics?
hypoventilation and vasodilation
What are the SE of inhalents on the respiratory system?
respiratory acidosis (leads to arrythmias) bronchodilation interfere with hypoxic pulmonary vasocontriction
Which inhalent needs a special vaporizor?
desflurane (boils at room temp)
What is an example of neuroleptanalgesia?
fentanyl + doperidol
What is the Frank Starling Law?
greater volume of blood in heart during diastole = more forceful contraction
What class of diuretics is best for edema, especially pulmonary?
loop diuretics - supplement K
What class of drugs are venodilators?
nitric oxide donors (nitrates)
What class of drugs are arteriolar dilators?
hydralazine, calcium channel blockers
What classes of drugs are mixed vasodilators
alpha 1 antagonist (pure artery dilator?)
ACE inhibitors
What are two important considerations when using nitroglycerin to venodilate?
tolerance
extensive first pass hepatic metabolism –> transdermal cream
What venodilator is helpful in small breed dogs with mitral regurgitation?
isosorbide dinitrate
What venodilator is used in hypertensive crisis and given IV?
nitroprusside
What is the MOA of hydralazine?
increases vasodilatory prostaglandins –> directly dilates arterioles
What is a common SE of hydralazine?
GI upset
What artery dilator is selective for blocking calcium channesl in smooth muscle only?
dihydropyridines (amlodipine, other pines)
What is the main use of amlodipine?
arteriolar vasodilation in hypertensive cats
What receptors does carvedilol act on?
pure alpha 1 antagonist
also B1 and B2 antagonist
What is the use of prazosin in CHF?
alpha 1 antagonist, reduces afterload, mixed dilator, no beta activity
What are the 3 major effects of Angiotensin 2?
direct vasoconstriction, aldosterone release, ADH release
What ACE inhibitor does not reduce GFR and is good to use in cats?
benazepril
What are the 4 ACE inhibitors?
enalapril, captopril, lisinopril (all reduce GFR)
What are the 3 adverce effects of ACE inhibitors?
vomiting or dirrhea, decreased kidney fxn, hyponatremia
What is the MOA of ACE inhibitors and kidney dysfucntion?
angiotensin 2 preferentially constrics efferent arterioles increasing GFR —> ace blocks these
What are the 3 classes of positive inotropes?
digitalis, inodilators (calcium sensitizers, bipyridines), sympathomimetics
What is the MOA of digoxin?
inhibits Na/K atpase that is responsible for membrane potential
What are the 3 indictions for digoxin?
positive inotrope in dilated cardiomyopathy
supraventricular tachyarrhythmias
degenerative valve dz
What is the MOA of positive inotropic drugs?
inhibit myocardial phosphodiesterase –> increase in cAMP and calcium avaailability
What drug increases contractility without increase in O2 consumption? What is MOA?
pimobendan
increases affinity of troponin C for calcium and inhibits PDE3 in vascular smooth muscle –> vasodilation
What positive inotropic drug is used for acute mgmt of heart failure and cardiogenic shock?
dobutamine