Pharmacology, Drug Class, and Body Systems Flashcards
The study of the movement of drugs through the body
Pharmacokinetics (Absorption, Distribution, Metabolism, Excretion)
The study of the effects of drugs’ actions on
Pharmacodynamics
Terms that are named for the person who discovered the illness or procedure?
Eponyms
Error-prone abbreviation
U, ug, QD, Hs, QOD, SC or SQ
Error-prone symbols
Trailing zeros and naked decimals
Trailing zeros
Medication written as 5.0 mg can be easily misinterpreted as 50 mg.
The recommendation, in this case, is to write the medication dose as 5 mg.
Naked decimals
Medication written as .5 mg can be easily misinterpreted as 5 mg if the decimal is unclear.
Instead, the dose should be written as 0.5 mg.
Drug Nomenclature
Chemical name, generic name, brand name.
The FDA defines drugs as these items:
. A substance recognized by an official
pharmacopeia or formulary
. A substance intended for use in the
diagnosis, cure, mitigation, treatment, or
prevention of disease
. A substance (other than food) intended
to affect the structure or any function of
the body
Chemical Name
Long scientific name that represents a drug’s
molecular structure.
Generic Name
Nonproprietary name of the drug that isn’t
protected by patent or trademark.
Brand Name
Name given by a manufacturer that holds
proprietary ownership, or patent, of the drug.
Dosage Forms
Oral, parenteral, Topical, other
Therapeutic Equivalence
when two drugs have the same clinical effect.
Bioequivalent
both drugs are equally effective and safe, and are equally absorbed when taken in the body.
The Orange Book
The FDA keeps a list of all therapeutic equivalents in a book called the Orange Book.
Pharmaceutical Alternatives
they have the same active ingredient, but are different strengths or dosage forms.
Therapeutic Interchange
occurs when a patient’s drug is substituted with a drug that has a different chemical makeup but the same result.
Before prescribing drugs, a physician must know which of
the following aspects that relate to the medicine?
What will the drug do to the body?
Will the drug have any side effects?
What will the body do with the drug?
How much of the drug is required by the body?
Pharmaceutics
The specific dosage form of a medication is designed to achieve
maximum benefit and to avoid side effects.
Therapeutics
Drugs have effects,
which lead to treatment
of disease.
Bioavailability
Only a portion of the drug
enters the bloodstream and
affects the body.
Passive Diffusion
Movement of drug molecules from an area of high
concentration of the drug to an area of low concentration
Doesn’t require energy
Example: Respiratory gases like oxygen
Facilitated Diffusion
Uses special carrier protein molecules to move drugs
across the membrane
Does not require energy
Example: Glucose
Active Transport
Requires energy or ATP to move drug molecules
across cell membrane
Movement occurs in one direction
Can move from lower concentration to higher
Less common method
Example: Sodium/potassium pump
needed to transport amino acids, sugars, and
lipids.
Bulk Transport
Phagocytosis (“Cell eating”)
Pinocytosis (“Cell drinking”)
Phagocytosis (“Cell eating”)
Cell membrane physically engulfing the drug molecule
Example: White blood cell engulfing an invading bacterium
Pinocytosis (“Cell drinking”)
Drug molecules are surrounded and brought into the cell.
Example: Vitamin B12 in the GI tract
Metabolism
Enzymes alter drugs in the liver (biotransformation) Preapares drug for excretion
Excretion
Excretion is a process by
which drugs are removed
from the body.
The process of drug removal is
also known as elimination.
This is the final step in pharmacokinetics.
Most elimination occurs in the kidneys and
into the urine.
Clearance is the rate at which drugs leave
the body.
Clearance is varied and is measured by
half-life elimination.
Half-Life Elimination:
Term used to describe how long it takes for the drug
concentration to decrease by 50%.
Distribution
impacted by blood flow to the affected area,
cell membrane permeability, and the chemical properties of
drugs.
Agonist Chemicals
A chemical that binds to the receptor and elicits an appropriate response
Antagonist Chemicals
A chemical that binds to the receptor but elicits no response and blocks access to the receptor by an agonist
Therapeutic Effects
Intended effect:
Local Effects
Decreasing inflammation at site of injury
Treating itchiness
Systemic Effects
Reducing fever
Lowering cholesterol
Reducing blood pressure
Therapeutic window (therapeutic index)
The range between the specific drug concentration needed to produce a desirable therapeutic
effect and the concentration that will cause toxicity
Adverse Effects
Negative effects of a drug:
These may occur even when taken as prescribed
at normal therapeutic dosages.
Nausea
Vomiting
Headache
Aches and pains
Toxicity:
Toxicity may also cause side effects.
Toxicity:
Harmful effect of a drug that occurs
when plasma concentration is higher than the
recommended therapeutic level.
Factors Affecting Drug Actions
Types of Effects
Patient demographics
Genetic factors
Associated diseases
Psychological factors
Route of administration
Patient compliance (example: taking all
doses as prescribed)
Environmental factors
Drug Interactions
is the result of a drug being taken with another substance that may change the drug’s intended effects. (Synergistic, Antagonistic)
Synergistic
When a drug and another substance are taken together, the combined effect is greater than the effect of each taken separately.
Antagonistic
When a drug and another substance are taken together, the combined effect is less than the effect of each taken separately. The two substances interfere with each other.
