wk 12-14 quiz Flashcards
List good client communication skills and strategies
clear and concise, respectful, talk slowly, discuss important info without animal, go over entire prescription and demonstrate if necessary
pharmacokinetics
physiological movement of drugs within
the body and includes the mechanisms of drugs moving into, throughout, and out of the body
List the 4 steps of pharmacokinetics
- Absorption
- Distribution
- Metabolism/ Biotransformation
- Excretion
List 4 different mechanisms of drug transport across cell membranes
- Passive diffusion
- Facilitated diffusion
- Active transport
- Pinocytosis/Phagocytosis
passive diffusion
Movement of drug molecules from area of high concentration to an area of low concentration
facilitated diffusion
Uses carrier molecules within the cell membrane to passively carry drug molecules
active transport
Movement of drug molecules with a carrier molecule that pumps the molecule across a concentration gradient
pinocytosis/phagocytosis
Cell drinking/cell eating
List and briefly describe drug characteristics that affect absorption
Solubility
pH
Molecule size
Route of administration
List and briefly describe animal characteristics that affect absorption
Age, Sex, Species
Health status
Metabolism and Genetics
bioavailability
The amount of given drug that is absorbed and reaches circulation
Describe the factors that affect bioavailability
Route of administration
Blood supply to the area the drug was given
Surface area available for absorption
Mechanism of drug absorption
Compare and contrast onset of action, duration of effect, and volumes given for each drug route of administration and how that can affect bioavailability
quicker onset = shorter duration of effect
distribution
Movement of drugs from the bloodstream to the target tissue or site of action
Describe how tissue perfusion affects drug distribution
Amount of blood flow to an area
Higher perfusion = quicker distribution
Lower perfusion = slower distribution
Describe how membrane permeability affects drug distribution
Some larger molecules cannot easily pass through smaller vessels
Describe how protein binding affects drug distribution
If a drug binds to a larger protein in the blood, it may get stuck in the bloodstream and not able to leave the capillaries to be distributed
Define volume of distribution and list factors that can affect this
How well a drug is distributed; Concentration and volume of drug given can affect this; Can be affected by diseases with increased body fluid concentrations (ascites, edema, etc.) May need more drug
List the primary site of Biotransformation and the name of the main enzyme association with this
liver; Cytochrome P450
List the 4 main pathways of biotransformation
Oxidation reactions
Reduction reactions
Hydrolysis
Conjugation
List the ways that drug interactions can occur during biotransformation
Synergistically: Drugs given together will produce a greater individual response than if given separate
Antagonistically: Drugs given together will produce a lessened individual response
Altered absorption
Competition for binding sites
Altered excretion
Altered metabolism
Describe the main factors that affect biotransformation
- plasma protein binding
- storage in tissues and and fat depots
- liver disease
- age of patient
- nutritional status of patient
- species and individual variation
- body temp
- route of administration
List the primary and secondary methods of drug elimination
kidney is primary; liver secondary
List the lesser methods of drug elimination
Milk, saliva, lungs, sweat
Define how drug elimination is related to drug withdrawal times in food animals
Muscle, liver, kidney, milk, egg, etc. samples are taken and analyzed for
drug residues when establishing withdrawal times depending on the use of the animal
List the 4 main factors affecting drug elimination
Hydration status
Age
Health
Blood pressure
MEC
minimum effective concentration; minimum plasma drug level needed for the drug to work
MTC
minimum toxic concentration; plasma drug level where we first see toxic effects
Peak plasma levels
highest concentration of drug in the plasma after it is given
therapeutic range
drug concentration in the animal that produces the desired effect without toxicity
Loading dose
higher initial drug dose given to get the drug concentration up to the therapeutic range in a quicker amount of time
Maintenance dose
dose of drug that maintains the drug in the therapeutic range
Steady State
constant level of drug concentration in the plasma
Half- life
time required for the amount of drug in the body to be reduced by half its original level
ED50
effective dose 50; dose of a drug that causes the defined effect in 50% of animals that take it
LD50
lethal dose 50; dose of a drug that will kill 50% of animals that take it
Margin of safety
the difference between a drugs ed50 and ld50
Affinity
strength of binding between a drug and it’s receptor
Agonist
drug that binds to its receptor and causes an effect
Antagonist
drug that inhibits or blocks the response of a cell when the drug is bound to the receptor
Explain what a peak plasma level is and how the drugs plasma concentration affects this
when drug elimination rate equals absorption rate; increases with extent of absorption
Contrast peak plasma levels in drugs given via different routes of administration
intravenous reaches peak plasma levels fastest
Explain the difference between high and low affinity
A drug with a higher affinity for a receptor can compete with or displace another drug that binds the same receptor but has a lower affinity
