Test 2 RT Flashcards
Tell me about the hearts pump system.
The heart is a 2 pump system. The small pump on the right side of the heart pumps blood to the lungs and back to the heart and the larger stronger pump on the left pumps blood throughout the remainder of the body. Also it is a closed system.
What is the passage of blood in the heart starting from the body?
From the BODY through the superior vena cava to the RIGHT ATRIUM to RIGHT VENTRICLE to the LUNGS via the pulmonary arteries then back into the heart to the LEFT ATRIUM then the LEFT VENTRICLE to the body from the aorta
What is are the muscular cells of the heart called?
Myocardial
What is afterload?
Pressure that the ventricles must create to eject the blood out of themselves into the aorta or pulminary artery
What happens if an animal has hypertension?
Arteries are smaller
Harder to push blood into the vessels
Little pressure and more force
What are examples of sodium channel blocker antiarrhythmic drugs?
Lidocaine, Quinidine, Procainamide
LQP
Talk to me about Lidocaine
Lidocaine selectively decreases firing of ectopic focus cells without significantly depressing the function of the normal conduction system.
Cats should be given this at lower dosages as they are more sensitive to the side effects
What trade name works similar to lidocaine but can be given orally?
mexiletine
Talk to me about Quinidine and Procainamide
They control both ventricular ectopic foci and atrial flutter or fibrillation, Injectable procainamide may be seen in small animals occasionally.
Quinidine may be seen in use to control artial fibrillation in horses
What are antiarrhythmic beta blockers?
drugs that block beta 1 sympathetic nervous system receptors on the heart leading the parasympathetic nervous system effects to dominate
They basically calm down the heart from beating too fast.
overtime we will see upregulation where the animal becomes resistant to the effects of the drug
Examples of antiarrhythmic beta blockers.
Propranolol - non selective
Atenolol - hypertension, feline cardiomyopathy
Carvedilol - general
Metoprolol - cardiomyopathy in cast
Esmolol - short acting
PACME
Pacmen
What two antiarrhythmic beta blockers are used to treat cardiomyopathy in cats?
Atenolol and Metoprolol
What are example of calcium channel blockers?
What are they used to treat?
What is the problem with them?
Verapamil and Diltiazem.
Treatment of supracenticular tachycardia, atrial fibrillation and atrial flutter
The problem is they decrease the strength of heart muscle contraction
VD view to see calcium channel blockers
What do positive inotropes do?
They increase the strength of contraction of a weakened heart.
What is an example of a vasoldilator and positive inotropic drug? What is its purpose?
Pimobendan: Vetmedin
it increases calcium binging with the contractile elements resulting in a more effective contraction of cardiac muscle cell
What is the purpose of vasodilators?
These drugs are used to relieve some of the cardiac workload
o Opening constricted sphincters
o Decreasing resistance to flow
o Making it easier for the heart to pump blood through vessels
Also most of them work by blocking the renin-angiotensin-aldosterone system
What are the three classification of Vasodilators?
Arterial, Venous, and Mixed
What are examples of Arterial Vasodilators and what do they do?
Amlodipine
- hypertension in dogs and cat (secondary to kidney disease)
Hyralazine
- mitral valve disease
What are examples of Venous Vasodilators and what do they do?
Nitroglycerin
- primarily relaxes blood vessels on the venous side of circulation. It treats pulmonary edema secondary to heart failure
- wear gloves with this one
Ignore my brain
Venous is venomous so wear gloves with nitroglycerin
What are example of Mixed Vasodilators and what do they do?
Nitroprusside
- short term use to help stabalize dogs and cats
- potent
Ace inhibitors such as Enacard (enalapril), Fortekor (Benazepril), Prilium
List three ace inhibitors and their trade names
Enalapril - trade name: Enacard
Benazepril - trade name: Fortekor
tradename prilium
either end or start with pril?
What is an ARB?
Angiotension Receptor Blocker
example is Semintra (what buddy takes)
- used to used to treat arterial hypertension and reduce proteinuria in cats
its used for hypertension in cats
Discuss vasoconstriction.
Vasoconstriction is a protective mechanism. It happens in a small part of the circulatory system aka the arterioles (small arteries which are located between the arteries and the capillaries).
The arterioles contain one or two layers of smooth muscle that can squeeze the vessels
What is the trade name for Acetylaicylic Acid?
Aspirin
What is the trade name for Acetylaicylic Acid? What does it do?
Aspirin
It inhibits the formation of prostaglandins and thromboxanes
It also reduced the aggregation of platelets
Use with caution with cats (48-hour dose interval to allow for metabolization
What do diuretics promote and reduce?
Diuretics promote the reduction of preload through the process known as ‘diuresis’
They reduce the harmful effects of pulmonary edema, ascites, and increased cardiac work
What are Ancillary drugs?
Bronchodilators
These drugs increase the size of lung passageways to allow more efficient oxygenation of blood
What are the type of renal / urinary drugs?
Diuretics, blood pressure lowering, urinary incontinence and urolith treatment
What do Diuretic do?
They will increase urine formation (volume of urine) and promote water loss from tissues, as well as decrease edema and lower blood pressure
or
Diuretics are drugs used to remove excess extracellular fluid by increasing urine flow and sodium excretion and by reducing hypertension
How do diuretics work in the kidneys.
Diuretics block the reabsorption of sodium and chloride ions while making urine. The sodium then has nowhere to go but out of the kidneys and into the urinary bladder. This will promote water to follow the sodium
When you eat something salty you need water to wash it down
What are the clinical effects of Diuretics?
Increased volume of urine excreted by kidneys & promote release of water from the tissues
Lower fluid volume in tissues – decreasing edema and lower blood pressure
Reduce udder edema in cattle & promote voiding to enhance toxin removalT
What are the types of Diuretics
Loop, osmotic, Thiazide and Thiazide-like, potassium-sparing, carbonic anhydrase inhibitor, and methyzanthines
What diuretic is the most potent?
Loop diuretics
What do loop diuretics do?
Prevent the reabsorption of sodium and chloride from the Loop of Henle
This retention of sodium in the forming urine osmotically retains water in the urine – preventing water reabsorption back into the body and results in a water loss as urine
How does loop diuretic not result in sodium loss?
Because sodium is so important to the body, the distal convoluted tubule has an active transport mechanism by which sodium is reabsorbed and potassium is excreted in exchange for the sodium
Common loop diuretics examples
Furosemide: LASIX®
- exercise induced pulmonary hemorrhage
- Pulmonary edema , CHF , hypertension
How do Osmotic Diuretics work?
Retains water in the renal tubules by its physical presence
It is freely filtered into the Bowman’s capsule BUT POORLY reabsorbed from the renal tubule …this provides a solute that ‘osmotically’ retains water in the renal tubular lumen.
Sodium , Chloride , Potassium , Water: are excreted
DIURESIS BEGINS WITHIN 15-30 MINUTES AND LASTS 3-4 HOURS BECAUSE IT IS HYPEROSMOLAR IT CAUSES WATER TO MOVE OUT OF CELLS AND INTO THE VASCULAR SPACE THIS CAN CAUSE A CIRCULATORY OVERLOAD and IT SHOULD NOT BE USED IN PATIENTS WITH HEART FAILURE.
SOMETIMES USED TO PROMOTE THE RENAL ELIMINATION OF TOXINS
Example of Osmotic Diuretics
Mannitol which increases renal medullary blood flow and decreases intracranial intraocular pressure
Discuss Thiazide Diuretics
Acts directly on the distal convoluted tubule to block sodium reabsorption (and promote chloride ion excretion)
Long term thiazide use causes excessive potassium excretion leading to Hypokalemia and Cardiac dysfunction
Examples Hydrodiuril
Discuss potassium sparing diuretics
The site of action is in the distal convoluted tubule and collecting ducts to, promote sodium-ion excretion (and water excretion), and retain potassium (therefore hyperkalemia possible)
Sometimes referred to as aldosterone antagonists
Example Aldacton (Spironolactone)
What is an acetazolamide? What does it promote?
Carbonic anhydrase inhibitor
Promote the excretion of sodium, potassium, bicarbonate and water
decrease the production of aqueous humor therefore reduce intraocular pressure= used for Glaucoma
What is used to treat ‘spinal cord bladders’ where there has been damage to the nerves which control relaxation of the urinary bladder outflow sphincters? Can you name an example?
cholinergic agents
Bethanechol
What is used to treat urinary incontinence?
Anticholinergins
What are anticholinergics?
they promote urine retention in the bladder. These drugs block the binding of actycholine to its receptor sites and therby cause muscle relaxation
Examples:
Propantheline (Pro-Banthine® -human label)
Butyl hyoscine (Buscopan®)
DICYCLOMINE
Buscopan is also an antispasmodic
Whats an example of an estrogen treatment hormone responsive urinary incontinence seen mainly in female spayed dogs?
diethylstilbestrol
as a woman i want to DIE thanks to my estrogen
List the respiratory mechanisms
Nasal cavity and cilia
reflexes
mucociliary clearance
What are the categories of respiratory drugs?
Antitussives
Mucolytics, expectorants, decongestants
Stimulants
Antihistamines
Bronchodilators
A Muscular Seal Abandons Babies
What are the protective mechanisms of the respiratory system?
Goblet cells - produce mucus
Nasal cavity and Cillia
Reflexes - cough or sneeze
What are the therapeutic principles of the respiratory system?
Control secretions,
control refleces
maintain normal airflow to alveoli
Describe antitussives.
Vet med only uses centrally acting antitussives such as butorphanol, hydrocodone, codeine, and dextromethorphan
Centrally acting agents suppress coughing by depressing the cough center in the brain
Coughing can be suppressed by an _____ or a _______ if the cough is ________
antitussive or a bronchodilator if the cough is nonproductive
What is Butorphanol Tartrate used as?
For chronic , non-productive coughs. It is also used as a pre-anesthetic and as an analgesic.
Can cause sedation @ high dose and ataxia
What are the two types of coughs?
Larynx and pharync
- sudden
- violent
- retching
Lower trachea and bronchi
- deep
- forceful cough
Tell me about hydrocodone.
trade name: Hycodan
It is an opioid, controlled substance
long term use results in constipation
this drug is a target for diversion
Tell me about codeine
an antitussive opined
It has poor and inconsistent absorption is administered orally
often combines with acetaminphen
Tell me about Dextromethorphan
Trade name Robitussin in humans
It is not a narcotic like the rest
it elevates the cough threshold and suppresses the non productive cough
Warn owners about this product
When should you use a expectorant?
With a productive cough
Whats the purpose of a expectorant?
to increase the fluidity of mucus by generating watery secretions by respiratory tract cells. It increases the amount of fluid moved from the lower respiratory tract to a point where it can be coughed up or spit out
Example of Expectorants
Guaifenesin glyceryl guaiacolate ; Guailaxin
Tell me about Mucolytics
they break up the mucus, decreasing the viscosity therefor cilia should be able to clear
An example is Acetylcysteine, trade name: Mucomyst® , Mucosil-10®
Tell me about decongestants.
stimulate α1-receptors causing vasoconstriction of blood vessels of nasal passages
Relieves congestion by reducing the swelling of the mucous membranes
An example is Phenylpropanolamine with trade name Propagest®️ , Pro-in®️
Tell me about Respiratory Stimulants
Act on the central nervous system to stimulate teh respiratory center of the brain
Example - Doxapram Hydrochloride, trade name: Dopram-V
Tell me about Respiratory Stimulants
Act on the central nervous system to stimulate teh respiratory center of the brain
Example - Doxapram Hydrochloride, trade name: Dopram-V
What are the major types of brochodilators?
Beta 2 Adrenergic Agonists and Methyxanthines
Discuss what Beta 2 Adrenergic Agonists are
they stimulate beta 2 receptors on the smooth muscle fibers of the bronchioles. This relaxation of the muscle produces bronchodilation
Examples include
Albuterol (Ventolin®️)
Clenbuterol (Ventipulmin®️ or Respipulmin Syrup ®️)
Injectable
Granules
Syrup
Terbutaline
Salmeterol (Advair ®️ MDI)
Metaproterenol (Alupent ®️)
What can beta 1 stimulation produce?
tachycardia and an inotropic effect
Discuss Methyxanthines
they are bronchodilation promoters that cause mild cardiac and respiratory stimulation and minor diuresis
Examples: Theophylline and aminophylline
What are the minor drug types of broncodilation?
Anticolinergics and antihistamines
How do anticholinergics work
combine with the acetylcholine receptors on the smooth muscle fibers & prevent the broncho-constricting effects of acetylcholine ; = bronchodilation
They are not widely used for respiratory conditions
Can be used if there is an organophosphate toxicity
Examples
Atropine: Atropine SA, Atropine LA
Glycopyrrolate: Robinul-V®️
Aminopentamide: Centrine®️
Ipratropium bromide
Buscopan in horses
Describe what an antihistamine does
It blocks the effects of histamine which is released from the mast cells in an allergic response
Examples
* Chlorpheniramine (many++)
* Cyproheptadine (Periactin)
* Diphenhydramine (Benadryl)
* Hydroxyzine (Atarax)
* Clemastine (Tavist)
Discuss the Parasympathetic system
Influences of the PNS on GI tract will be to increase all of the following:
* Digestive secretions
* Blood flow to the gi tract
* Gut motility
* Smooth muscle tone
What is Gastrin?
It is a hormone of the endocrine system that is released from the stomach wall in response to the presence of proteins, distention of the stomach, and increased stimulation by PNS
What are the hormones of the endocrine system
gastrin, secretin and cholecytokinin
What are locally released compounds of the autonomic nervous system?
histamine, serotonin, prostaglandin, and acetylchloine
What is acetyclonine
a neurotransmitter that increases stomach acidity
What is histamine released by?
Basophils and mast cells
What must you keep in mind about bacterial toxins?
toxins produced by certain bacteria in the GI tract can stimulate secretions of electrolytes which will draw fluids from intestinal cells and the animal will get severe diarrhea and dehydration
What are the types of GI Drugs
Emetic
Antiemetic
Antidiarrheal
Laxative, Cathartics, Purgatives
Antacids and Antiulcer
Drugs for rumen health
Miscellaneous
E A A L C P A A R M
How do emetics work?
By stimulating selected receptors which will activate the physiologic mechanisms that will make the animal vomit
What are the major receptors stimulated by emetics
Acetylcholine
Muscarinic cholinergic
Histamine
Dopamine
Serotonin
Alpha Adrenergic
Substance P
What are the five mechanism of receptors of the emetic centre?
- Direct stimulation of emetic centre neurons
- Direct stimulation of CRTZ that signal the emetic centre. Detects substances in the blood and CSP
- Nerve signals from distended or irritated areas in body
- Nerves of inner ear send signals to emetic centre
- Higher centres of the brain, emotional centers aka fear anxiety
Neurons of the emetic center have ____________receptors, and ________ receptors.
alpha (α) adrenergic and seratonin
The emetic center is protected by the blood by the _______________(three words)
Blood Brain Barrier
What is the Chemoreceptor Trigger Zone
It is a specialized area of receptors in the CNS that is capable of detecting toxic substances in the blood and cerebrospinal fluid
Whats an example of a centrally acting emetic typically only in dogs?
Apomorphine because they have more dopamine than cats
What is an example of a centrally acting emetic more effective for cats?
Xylazine becuase they have more alpha 2 receptors than dogs
What are example of locally acting emetics?
3% H2O2
NaCl
Syrup of Ipecac
What is the difference between emetics ansd antiemetics?
emetics promotes vomiting and antiemetics treats vomiting and nausea
What do antemetics do?
They block receptors in the CRTZ, emetic centre, and peripheral receptors that signal the brain
What are Phenothiazines?
Antiemetics that blocks dopamine receptors, H1 receptors, muscarinic receptors in CRTZ and emetic center
Examples
- Acepromazine
- Chlorpromazine
- Prochlorperazine
Phenothiazines should be cautious of ___________ animals.
hypotensive
What is Metoclorpamine?
A centrally acting and peripheral antiemetic that blocks dopamine receptors at regular doses and also serotonin receptors at higher doses
It promotes gastric emptying and increases castric contraction
Prokinetic drug
Ther trade name for this is Reglan
Whare are antihistamines?
Antihistamines are antiemetic drugs that lock H1 receptors on the CRTZ
It decreases the signal from the inner ear vestibular apparatus
Examples
- Benadryl : Diphenhydramine
- Dramamine : Dimenhydrinate
- Phenergan: Promethazine
BPD DDP
What are the four types of antidiarrheals?
Secretory
exudative
motility
osmotic or malabsoption
How do antidiarrheal work?
They work by decreasing secretions from GI tract wall, modifying the intestinal motility and decreasing the underlying problem that is stimulating changes to secretion and motility
How do narcotic work as an antidiarrheal?
They increase intestinal absorption and decrease peristaltic contraction and increase segmental contractions
Is atropine uses as an antidiarrheal often? Why or why not?
No it is not since it have many side effects and a short duration of action
Pepto bismol in the vet world?
Kaeoectate
it coats the intestinal mucosa and decreases inflammation
used in caution with cats
What are protectants
Compounds designed to cover the intestinal wall to form a physical blanket or barrier that protects it
What are the two types of laxitives?
Emollient (lubricants) and Bulk
What are the types of cathartics?
osmotic and irritant
What are nonsystemic antacids that work for constipation?
Calcium and aluminum
What are nonsystemic antacids that work for Diarrhea?
Magnesium
What are systemic antacids?
- Cimetidine : Tagamet™
- Ranitidine : Zantac™
- Famotidine : Pepcid™
- H2 antagonists
What is Omeprazole - Gastroguard
proton pump blocker
Binds to the luminal surface of the parietal cell and inhibits the pump that normally transports hydrogen ions into the stomach lumen
