Pharm test 2 Flashcards
Why might we use antitussives with caution for therapy?
They are narcotics
Explain the order of administration for Syrup of Ipecac and Activated Charcoal and the rationale that supports it.
- syrup of ipecac should be administered first.
- wait ~20 minutes since it has to pass through into the small intestine to act as an irritant
- animal vomits
- administer activated charcoal now to adsorb any remaining toxin left
Explain the term “up-regulation” as it pertains to β – blocking drugs used to heart disease, and the implications and concerns for the administration of these types of drugs?
Indicates that the body has responded to receptor activity being blocked so receptors have been taken up by the drug and therefore the body responds by producing more receptors needing an alteration increase in drug dose
The concern is that if the medication were to be stopped suddenly, all of the receptors – original ones AND now the additional ones will function and the result would be an extreme tachycardia event.
For the two emetics, Xylazine and Apomorphine, which species do they work best in?
Xylazine = Better in cats because they have more alpha 2 receptors
Apomorphine = Dogs because they have more dopamine receptors
What are receptors of the Sympathetic –> Adrenergic system
Alpha 1
Alpha 2
Beta 1
Beta 2
What are neurotransmitters of the Sympathetic –> Adrenergic system
Epinephrine
Norepinephrine
Dopamine
What are receptors of the Parasympathetic-> Cholinergic system
Muscarinic
Nicotinic
What are neutrotransmitters of the Parasympathetic-> Cholinergic system
Actylcholine
What do the Cholinergic system do
Slow HR
Increase blood flow to the GI tract
Decreases bronchiole diameter
What does the adrenergic system do
Increase HR and force contraction
Elevated BP
Decreased activity of GI tract
Briefly explain the mechanism of action for hyperosmolar laxatives
Are hypertonic salts that are poorly absorbed but they do create a strong osmotic force which attracts water into the bowel lumen.
Briefly explain the mechanism of action for Locally acting emetics
Iritating the GI tract, distending the stomach, and/or stimulating parasympathetic nerves to send signals to the emetic center in the central nervous system
Briefly explain the mechanism of action for Anti bloat medications
Designed to reduce gas buildup or facilitate the removal of gas from the rumen. Normal rumen and reticulum contractions allow partially digested plant food (the cud) to be regurgitated up the esophagus into the mouth, where it is chewed and swallowed (rumination or “chewing the cud”)
Explain why propranolol, an antiarrhythmic drug, may contribute to dyspnea ( difficult breathing) in animals with respiratory disease.
its antagonist effect means this drug also has the capacity to block stimulation of β2 receptors cause bronchodilation which affects breathing for patients
How does vasoconstriction occur as a consequence of heart failure, and how can it make heart failure worse?
CHF leads to decreased BP which Baroreceptors are BP sensors. When BP decreases the baroreceptors don’t send the signal to the brain to stop SNS from working, so the brain activates the SNS activity leading to vasoconstriction.
Makes it worse because in congenital heart failure, the heart is already weak to begin with. So even though vasoconstriction increases the blood pressure, it makes the heart work much harder to pump the blood.
What are the steps by which the renin-angiotensin system produces vasoconstriction and water retention?
1.Decreases arterial BP due to dehydration, blood loss, shock
2. That causes a decrease in BP with the blood flow to the kidneys and decreases urine filtration
3. Kidneys sense the BP decrease and start to produce renin in the blood
4. Renin convert angiotensinogen into angiotensitin 1
5. Moving Angiotensin 1 throughout the bloodstream and into the lungs comes across ACE
6. ACE enzyme converts Angiotensin 1 into Angiotensin 2 which is now the potent vasodilator
7. Angiotensin 2 stimulates adrenal glands that produce aldosterone which now causes increased reabsorption of sodium making blood volume increase
8. Vasoconstriction and increase blood volume will now raise the arterial blood pressure to normal
What are three possible complications of treatment with a loop diuretic?
Hypokalemia
Metabolic acidosis
Dehydration
Getting prescribed nitroglycerin, what precautions should owners take when treating this drug topically?
Drug can be absorbed through skin including owners, always wear gloves and tell everyone who is around that the cream is put on, as well as application of the patch should be changed with each dose
What unique method may apomorphine be administered?
Why is apomorphine administered this way? What is the aim of this route of administration?
Conjunctival sac
Going in the bloodstream it will take some time to diffuse across the barrier to reach the emetic center so it must achieve high blood concentrations quickly, so the CRTZ can be stimulated to produce emesis
It dissolves quickly and is rapidly absorbed through the mucous membranes, after desired effect the tablet is removed and the residue is flushed away
Why does enalapril cause vasodilation in animals with heart failure but have little effect in normal animals?
This drug is an ACE inhibitor that have a marked beneficial effect in animals with congestive heart failure
Normal animals show little response to these drugs because they have not activated the renin-angiotensin system, so there is no ACE present to inhibit with an ACE inhibitor
you overhear the veterinarian telling the owner of a cat with cardiomyopathy to administer aspirin. However, you remember that aspirin must be used with caution in cats. Is the doctor wrong to recommend aspirin for this cat?
Aspirin can be used in cats, but it must be used at doses that are lower than those used in dogs. The drug is designed to decrease the stickiness of platelets and therefore reduce natural clot formation often associated with feline cardiomyopathy.
Usually a 48 hr dose interval so the cat can metabolize and eliminate the drug
How does furosemide lessen the nosebleeds that racehorses experience during exertion?
What drug can be used?
Salix® –> Furosemide
Shifts fluid volume from the pulmonary circulation to the systemic circulation there by minimizing the pressure and reducing any hemorrhage.
When animals vomit, they become dehydrated from the loss of fluid in the vomitus and because they are not ingesting food or water. Why should an extremely dehydrated animal not receive a phenothiazine tranquillizer as an antiemetic before its dehydration is corrected with intravenous fluids?
Phenothiazines block alpha receptors, blocking the α1 receptor can block the body’s attempt to raise dropping blood pressure by blocking the vasoconstriction needed to do so. For this reason, animals hypotensive low BP should have the hypotensive state corrected before phenothiazine antiemetic therapy is initiated to prevent further decreases in blood pressure
What is the difference between a ruminatorics and an antibloat medication?
Which category does neostigmine belong to? What about docusate sodium succinate (DSS)?
- Prokinetic drug Stimulate an atonic rumen Not working properly that stimulate the parasympathetic nervous system to increase the motility of the GI tract.
- Anti-bloat is to free gas or frothy bloat
- Neostigmine is a ruminator drug that combines with the enzyme acetylcholinesterase and prevents it from breaking down the parasympathetic nervous system neurotransmitter acetylcholine.
- DSS is an anti-bloat medication
