Exam Review: Short Answer Flashcards
What precautions should be taken when working with DMSO (Dimethyl Sulfoxide)
Causes hyperglycaemia which causes water to move out of cells and into vascular space. This causes circulatory overload and should be avoided in patients with heart failure.
Explain the function of COX1 and COX2 enzymes as it relates to inflammation
COX1 is a normal regulatory function of the body whereas COX2 is produced only when activated by inflammatory cells. COX1 produces “good” Prostaglandin and COX2 produces “bad” Prostaglandin. NSAIDS that block both types will cause GI ulcers and other GI symptoms
A drug may exhibit a ceiling effect. What does this mean when it comes to Pharmokinetics of a drug. Give one example.
Ceiling effect is the same as the therapeutic level or MIC. Once a drug reaches this dose, increasing the dose will not increase efficacy, only toxicity. Ketamine is an example. In higher doses it can be an anesthetic and eventually toxic
What is the mechanism by which small doses of an antimicrobial can lead to the development of a resistant strain of bacteria?
Bacterial resistance occurs when the antibiotic therapy is not high enough to kill all of the organisms or the course of treatment is not completed. This results in the last standing, strongest organism to remain alive and passes its immunity onto its offspring. The bacteria is now Colonized and another antibiotic must be used.
Xylazine and Apomorphine are emetics. Which is better for cats? Which for dogs? How is Apomorphine administered (not IV or PO) and why?
Apomorphine works by releasing dopamine as a neurotransmitter and activating the Chemoreceptor Trigger Zone. It works best in dogs because cats have less dopamine receptors. Xylazine stimulates te CRTZ and emetic center. It is used in cats because they have more Alpha-2 receptors.
Apomorphine can be given via the conjunctival sac in the eye, is it easily and quickly absorbed.
How does plasma protein concentration relate to the amount of a drug administered?
The higher the plasma protein concentraton, the easier it will move to the blood and tissue. Less dose is needed.
Explain the first pass effect and how it determines the amount and route of a drug?
Primarily to drugs given PO. They are metabolized in the liver and may be completely absorbed or only partially before going into general circulation. Some drugs such as Valium cant be given PO because they are rendered useless by the liver. It determines the dosage to make up for the amount lost in he liver.
Identify 3 contributing factors to antimicrobial resistance
- Genetic changes that were inherited from previous generations
- acquire resistance as a result of spontaneous mutation
- acquire addition piece of DNA called an r-plasmid
In order, describe the 5 steps a drug undergoes during pharmacokinetic journy in the body
- Absorption: site of adminstration into tissue
- DIstribution: tissue to boodstream to be distributed to target tissues
- Localization in Target Tissue
- Metabolization: broken down in liver
- Elimination: excreted as waste
List 5 catabolic effects of long term use of a Glucorticoid agent due to breakdown of Protein
- Muscle atrophy
- Thinning of skin
- Loss of hair
- Pot belly
- Osteoporosis
What is the effect on T-lymphocyte numbers during Glucocorticoid therapy? This exposes the animal to what type of disease?
It decreases the numbers resulting in risk of infection or cellular damage
Explain upregulation as it relates to Beta-Blockers
Beta Blocking drugs when used longterm cause upregulation which is an increase in the number of receptors on the surface of target cells
