Pharmacology- Basic Concepts Flashcards
Drug
chemical(s) that act on living systems at the molecular level
Pharmacology vs.
Pharmacodynamics vs
Pharmacokinetics
the study of drugs and their effects on living organisms (pharmacology)
what a drug does to the body (pharmacodynamics)
what the body does to the drug; how drug moves in body (pharmacokinetics)
Toxicology
study of harmful or toxic effects of drugs
Generic Name
this is the active ingredient for the drug; it is the drug’s chemical makeup
Note: the first letter is not capitalized
Trade Name (and 2 other names for it)
brand, proprietary
the manufacturer’s name
Note: first letter is capitalized
Indications
approved use(s) of the drug
Warnings & Precautions
usually mild side effects or adverse effects (any effect other than the intended effect) that may occur with normal usage
Contraindications
medical conditions, physical conditions, or symptoms that make the drug inadvisable
Syngergism
enhanced desired effects when taking two drugs in combination vs each drug individually
If two drugs are synergistic, do you need to increase or decrease their doses?
decrease
they’re more powerful when given together, so you don’t need to give as much
Drug Tolerance
decreased effect of a drug over time
Extra Label Use
using a drug in any way other than the approved way
Classified Drugs
classification of abuse potential determined by US Drug Enforcement Agency (DEA)
What classified drug class is most at risk for abuse?
CI
Withdrawal Time
amount of time required before a food animal can be slaughtered to remove potential transfer to humans during consumption
Overdose
toxic effects that occur when too much drug is given or when drug accumulates in body
Compounding
manipulation of a drug that is not provided for in the FDA approved drug lable
What can happen to a drug that has been compounded?
slight changes may impact the drug’s action/performance
Enteral vs Parenteral
Enteral- uses the GI tract
Parenteral- goes directly to the source; bypasses GI tract
What are the pros/cons of enteral drug administration?
Pro- safest
Cons- slowest, most variable route
What are the 4 enteral ways to give medication?
PO
Sublingual
Submucosal
Rectal
Of the 4 ways to enterally give a drug, which avoid the first pass effect and which do not?
Avoid- sublingual, submucosal, rectal
Does NOT Avoid- PO
What is the first pass affect?
The orally administered drug travels to the liver before reaching systemic circulation and ends up getting removed before the drug is able to affect the rest of the body
How are submucosal meds absorbed?
via capillaries of mucous membranes (like bupe oral)
How are sublingual meds absorbed?
capillaries under tongue
What are the 8 ways to administer a drug parenterally?
IV IM SQ ID (intradermal) IO (intraosseous) IP (intraperitoneal) Topical Inhalant
What is an IO injection?
injection into bone marrow of long bone
Therapeutic Action
the desired response of a drug
Therapeutic Range
range between dose causing minimum effect and adverse effects
Therapeutic Index (TI)
the relationship between a drug’s ability to achieve the desired effect compared with its tendency to produce toxic effects
What does the TI ultimately tell you about a drug?
how safe it is to use
What is the mathematical equation to get the TI?
lethal Dose 50 / Effective Dose 50
What is effective dose 50?
the dose that produces the desired response in 50% of patients
What is lethal dose 50?
the dose that is lethal in 50% of patients
The _____ the TI, the safer the drug
larger
(because that means there is a bigger gap between a dose that is too small to work and a dose that is high enough it may have lethal effects)
Drug Potency
amount of drug needed to achieve the desired affect
Drug Efficacy
maximal response obtained by a drug; giving more drug will not increase this number
What does ADME stand for?
Absorption
Distribution
Metabolism
Elimination
Absorption
entry of the therapeutic agent into the bloodstream
Distribution
drug is sent out into the intended tissues
The rate and efficiency of absorption and distribution depend on the following (7)
Route of administration pKa (how well the drug ionizes) drug solubility pH of tissues perfusion of tissues volume of distribution other factors (ie. blood-brain barrier)
Metabolism
chemical alteration or modification of a drug molecule
Where does metabolism primarily happen? Secondarily?
Primarily- liver
Secondarily- kidneys, blood, lungs
Elimination
drugs and their metabolites are eliminated from the body via urine, feces, sweat, milk, tears, saliva, respiration
What is the primary route of excretion?
Glomeruli of the kidneys filter first and excrete waste into the urine
What is the other route of excretion aside from kidneys?
Liver if the drug is excreted via biliary excretion
Adverse RXN vs. Side Effect
Adverse reactions area broader category accepting any adverse effect occurring with drug concentrations within or outside of the normal therapeutic range. Side effects are only referring to those effects that occur within the therapeutic dosing range.
What are 3 things a drug can do once it reaches the target tissue?
- Bind to a receptor site and cause cells to react (agonistic) or prevent a reaction (antagonistic)
- Interact with ions in the body to create a chemical reaction
- By physical presence alone, the drug may facilitate a reaction
5 Rules for ELDU
- Licensed vet must order the drug
- VCPR must exist
- Health of animal will be threatened if drug were not able to be used
- No current FDA approved drug for this condition exists, or an existing FDA approved drug/dosage form would be clinically ineffective
- Extended withdrawal times
The 5 “Rights” of Drug Administration
drug time route amount patient