Lecture 1

Question 1

Drug

Answer 1

a substance used in the treatment, diagnosis, prevention, or mitigation of disease (Endogenous or xenobioitc)

Question 2

Pharmacology

Answer 2

A science of dealing with the properties of drugs and their effects on living systems. The properties and reactions of drugs especially with relation to their therapeutic value.

Question 3

Pharmacy

Answer 3

A separate and complementary health-care profession concerned with collection, preparation, standardization, and dispensing of drugs. The art or practice of preparing, preserving, compounding, and dispensing drugs. (Pharmacy ≠ pharmacology).

Question 4

Clinical Pharmacology

Answer 4

The branch of pharmacology that deals directly with the effectiveness and safety of the drugs in the clinical setting (patients)

Question 5

Dosage

Answer 5

The amount of drug given (dose), the route of administration, the interval between doses, and the duration of therapy (ex: 5 mg/kg orally every 12 hrs for 5 days)

Question 6

Potency

Answer 6

A relative measurement of biological activity. The amount of drug needed to achieve a specific biological effect. Potency is seldom of medical significance, and it is often confused with efficacy. (example given in class: one of the few times that potency matters would be with tranquilizers and large animals… you want the dose to be more potent so it can fit in a dart and not have to be infused gradually)

Question 7

Efficacy

Answer 7

effectiveness. The ability of a drug to control or cure an illness

Question 8

Excipients and binders

Answer 8

Used to bulk up solid formulations and help the active ingredient stick together.

Question 9

Vehicle

Answer 9

An inert medium or solvent/diluent in which the medically active substance is administered.

Question 10

ADME

Answer 10

The disposition of a drug as described by its absorption, distribution, metabolism, and excretion. i.e. pharmacokinetics

Question 11

Pharmacokinetics

Answer 11

A mathematical description of drug disposition in the body (e.g., half-life, volume of distribution, etc). Relates drug dose to plasma concentration.

Question 12

Pharmacodynamics

Answer 12

Relates the drug concentration to effect. It is what the drug produces physiologically.

Question 13

Tolerance

Answer 13

Responsiveness to drug decreases with continued administration

Question 14

Tachyphylaxis

Answer 14

Rapid development of tolerance
Example: vasodilation from nitroglycerin. 12 hour dose with the drug and then 12 hours without because the body becomes tolerant after 12 hours.

Question 15

Trade name of drug versus official name of a drug

Answer 15

Official name: (nonproprietary; often referred to as the “generic” name; NOT capitalized)
Langston will always give the official name (may give the trade name)
Trade name: (proprietary; proper noun, it is capitalized)
This is the company’s version of that drug – will include a registered or unregistered trademark
EX// o-p-dd; mitotane; Lysodren

Question 16

Adverse reaction: type A versus type B

Answer 16

Type A: an adverse event that can be anticipated based on the known mechanism of the drug. Usually dose-dependent.
Type B: an adverse event that is idiosyncratic (specific to the individual), unpredictable, and often nondose-dependent

Question 17

Therapeutic Index

Answer 17

lethal dose (toxic dose) of 50% of animals divided by the effective dose in 50% of animals (LD50/ED50). This is an index of safety and we use it as a qualitative term. It is more about a margin of safety rather than an absolute number. We want a drug with a high therapeutic index or high margin of safety.

Question 18

Extra‐label drug use

Answer 18

the use of a drug in species, route, dosage, or indication other than indicated on the label. Such use is allowed only by veterinarians and only according to the guidelines of the Animal Medicinal Drug Use Clarification Act (AMDUCA).

Question 19

Clinical Trial

Answer 19

a study to establish the safety and efficacy of a drug compared to a placebo or an established treatment.

Question 20

Placebo and Placebo Effect

Answer 20

Placebo: a substance or treatment with no active therapeutic effect given deceive the recipient into thinking that it is an active treatment
Placebo effect: a beneficial health outcome resulting from a person’s anticipation that an intervention will help them

Question 21

Suspension

Answer 21

colloids with a liquid continuous phase and solid dispersed phase. Water insoluble drugs may be given as a suspension

Question 22

Solution

Answer 22

The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent)

Question 23

Agonist

Answer 23

a substance binding to a receptor that induces a physiologic action

Question 24

Antagonist

Answer 24

a substance binding to a receptor that blocks the action of an agonist
A physiologic antagonist has an opposing effect at a different receptor. For example histamine (decreases blood pressure) and epinephrine (increases blood pressure)
A pharmacologic antagonist blocks the effect on the same receptor, these are drugs.

Question 25

Competitive antagonists

Answer 25

agonists and antagonists don’t permanently bind to a receptor so they are constantly binding and releasing. This means they must constantly compete with the other for the receptor. The magnitude of the effect of the agonist/antagonist is due to the amount of drug present and the drug’s affinity for the receptor.

Question 26

Noncompetitive antagonists

Answer 26

permanently bind to the receptor (new receptor must be created; rare)

Question 27

Dose-Response Curve

Answer 27

a curve that determines how much drug (x-axis) causes a particular effect or side effect in the body (y-axis). It also allows you to compare agonists and antagonists to the original drugs.

Question 28

peak concentration

Answer 28

The highest concentration of a drug in a patient’s bloodstream, usually right after a dose is administered

Question 29

LD50, ED50, LD1, Certain Safety Factor

Answer 29

LD50- dose that kills 50% of subjects ED50- dose that is effective in 50% of subjects LD1- dose that kills 1% of subjects Certain Safety Factor- (LD1/ED99) alternative to the therapeutic index as an index of safety -LD1/ED99 is now more commonly used than LD50/ED50

Question 30

Minimum Effective Concentration (MEC)

Answer 30

Lowest concentration that produces a desired effect

Question 31

trough concentration

Answer 31

The lowest drug concentration in a dosing interval. Always occurs immediately before the next dose.

Question 32

LD50, ED50, LD1, Certain Safety Factor

Answer 32

LD50- dose that kills 50% of subjects ED50- dose that is effective in 50% of subjects LD1- dose that kills 1% of subjects Certain Safety Factor- (LD1/ED99) alternative to the therapeutic index as an index of safety -LD1/ED99 is now more commonly used than LD50/ED50

Question 33

No Observed (Adverse) Effect Level (NOEL/NOAEL)

Answer 33

The maximum dose that does not produce toxicity. Same as maximum nontoxic dose.

Question 34

physiologic antagonist

Answer 34

occurs when drugs are antagonistic because of opposing effects at different receptors

Question 35

Partial agonists

Answer 35

Drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist.

Question 36

agonist/antagonist

Answer 36

Agonist- A substance binding to a receptor that induces a physiologic action Antagonist- a substance binding to a receptor that blocks the action of an agonist

Question 37

Know the proper grammatical use of drug trade names versus the official name of the drug; including capitalization rules and the use of trademark symbols.

Answer 37

Official Name/Generic Name- Not capitalized Trade Name- Capitalized A trade name is a proper noun identifying a company’s version of that drug. Typically the trade name of a drug is also a registered or unregistered trademark. The registered trademark symbol gives the company exclusive legal right to use that trademark. An unregistered trademark provides limited legal status but notifies public that the company considers the name as their property.

Question 38

Contrast potency versus efficacy in terms of the therapeutic utility of a drug.

Answer 38

Potency → the amount of the drug required to produce a certain response Efficacy→ maximal response that can be elicited by a drug Most potent does not always mean it is the most efficient, we want efficacy in a drug and not potency.

Question 39

Why might different injectable formulations exist for the same drug? Likewise for different oral formulations.

Answer 39

There are different formulas for different injectable and oral drugs because the same medicine can treat different diseases with different formulations EX: Ivermectin Dose is different for heartworm prevention vs sarcoptic mange There are also different formulations between each animal EX. Dogs and cats will not have the same formula Also, different formulation will last longer in the body -i.e. Penicillin with different ingredients make it lass water soluble thus making it "long lasting"

Question 40

Contrast the relative speed of onset for a drug with receptors located within the nucleus of a cell versus the cell membrane/enzyme/2ndmessenger.

Answer 40

Receptors in nucleus of a cell: e.g. steroids, receptor-agonist complex is internalized and translocated to the nucleus where it alters protein synthesis, slower acting Receptors in the cell membrane/enzyme/2nd messenger: e.g. insulin, activating ion channels, acts fast

Question 41

) Explain how the concentration of a drug at the receptor site and the affinity of the drug for that receptor affects the magnitude of the effect of a competitive agonist or a competitive antagonist.

Answer 41

A competitive antagonist binds to the same site as the agonist but does not activate it but instead blocks the agonist’s action. The magnitude of the effect is dependent on the amount of drug present and the affinity constant (rate of binding and release) of that drug for the receptor. A competitive antagonist binds the receptor in a reversible way without activating the effector system for that receptor. In the presence of a competitive antagonist, the log dose response curve is shifted to higher doses (to the right) but the same maximal effect is reached. A competitive antagonist can be overcome by adding more agonist. If you give more agonist than antagonist you can have the same effect but you just have to give a larger dose to have the same effect.

Question 42

Explain what a noncompetitive antagonist is and how it differs from a competitive antagonist in its ability to override an agonist of the same receptor.

Answer 42

block agonists by permanently binding to the receptor. New receptor must be created. Rare. A noncompetitive antagonist shifts the agonist curve downward, instead of to the right like a competitive does.

Question 43

Regarding drug interactions, what do the following terms imply: synergy, antagonism, and additive effects?

Answer 43

Synergistic: drugs work together to produce a stronger effect rather than one drug on its own. 2+2=5 Antagonist: drugs work against each other and have decreased efficacy. 2+2=1 Additive: drugs work as if they were being given on their own. 2+2=4

Question 44

Assuming a “normal distribution”, state the percentage of that population that would be expected to be encompassed by 1, 2, and 3 standard deviations from the mean response.

Answer 44

1 standard deviation away: 68.2% 2 SDs away: 95.4% 3 SDs away: 99.7%

Question 45

Be able to make necessary conversions in units of measurement.

Answer 45

Calculations

Question 46

Explain why the concentration of a drug might be stated in “units per ml” rather than “mg per ml”.

Answer 46

A unit is a measurement of biological activity. Units are used when there is difficulty creating the same potency (per weight of drug) in every batch of drug produced.

Question 47

Be able to make necessary conversions in units of measurement.

Answer 47

Calculations Lecture

Question 48

Be able to make common calculations including: Total dose administered for solid and liquid formulations, fluid replacement in dehydration and maintenance losses, w/v and v/v dilutions, constant rate infusions (CRIs; be able to adjust either infusion rate or drug concentration to achieve desired administration), intermediate dilutions, medicated feed calculations, medicated water calculations, loading doses, partial loading doses, dosage adjustment at steady‐state using therapeutic drug monitoring (TDM) results.

Answer 48

Calculations Lecture