CH 1 Intro to Pharmacology Flashcards
Drugs, or medicine, are substances that change the way a ____
living organism functions
Pharmacology
how drugs affect the body and
how it responds
Goal of drug therapy is to
cure, control, or relieve
a specific disease or medical condition
Pharmacological effect is a drug’s action on a…
living system
Therapeutic drugs are used to
treat or relieve symptoms of a disease or medical condition
Example: using an antibiotic to treat a skin infection
Prophylaxis
Prophylactic drugs are used to
prevent a disease or medical condition
Example: getting annual influenza vaccine to mitigate symptoms and prevent hospitalizations
Drugs sources
Plants, fungi, animals, minerals, chemicals, or (rDNA) recombinant DNA
Agonist is a drug that
activates and binds to receptors causing a response
Antagonist is a drug that
anti-activates the action of other drugs
Drugs can be embedded within cell membranes as related to their
lipid solubility
Pharmacokinetics how the body
how the body affects the drug
Pharmacokinetics describes the activity of a drug within the body over a period of time and is described through four processes…
Absorption
Distribution
Metabolism
Elimination
Absorption is a process whereby
unmetabolized drug travels from the site of administration and enters the circulatory system
primary site of absorption is…
The small intestine
Factors that can affect absorption
5 factors
Drug and food interactions (ex: grapefruit juice)
Drug solubility (ex:Lipid vs water soluble)
Route of administration (ex: po vs IV)
Drug formulations (ex:tab vs liquids vs size)
Gastric emptying (ex: Faster gastric emptying increases absorption rate)
Distribution is a process by which a drug …
moves from the blood into other body fluids and tissues and ultimately to its sites of action
Factors that can affect distribution
b.l.a.b.
Blood-brain barrier
Lipophilicity
Acid-base characteristics
Binding to plasma proteins & cellular constituents
Metabolism is a process by which food/drugs are
chemically converted to other biochemical compounds and then excreted through metabolic pathways
Primary site of metabolism is the
liver
other sites of metabolism include the
gastrointestinal tract, lungs, kidneys, and plasma
Prodrugs
meds that must be metabolized first to become therapeutically active
Most drugs do not require metabolism to become therapeutically active
True of False
TRUE
Induction
An increase in the amount of an enzyme available to metabolize a drug
caused by drugs, food, or smoking
Can increase or decrease the pharmacological response to other drugs or themselves
Inhibition
A decrease in the amount of an enzyme available to metabolize a drug
May cause an increase in concentration of other drugs leading to toxic pharmacological effects
Competitive inhibition
a drug blocks enzyme activity and impairs the metabolism of another drug
Can be overcome by increasing the dose
Noncompetitive inhibition
drug completely blocks enzyme activity and impairs the metabolism of another drug
Cannot be overcome by increasing the dose
Factors that can affect metabolism
d.a.m.g
Disease states (liver failure or cirrhosis
Age
Medications and drug interactions (inducers vs inhibitors)
Genetics (slow vs rapid metabolizers)
Elimination
removal of a drug or its metabolites from the body
Primary site of Elimination is
through the kidneys in the form of urine or through feces
Additional routes of elimination are
Liver, feces, saliva, perspiration/sweat, exhalation, or breast milk
Factors that can affect Elimination
k.a.d.
Kidney disease/infection
Age/genetics
Drug properties including size, polarity, pH, and solubility
Dose-Response Curve
relationship between the amount of drug administered (dose) and therapeutic effect (response)
Ceiling effect
Point where additional doses will not improve clinical response or adverse effects outweigh beneficial effects
First pass metabolism
A portion of the drug is metabolized before reaching systemic circulation
IV admin meds aren’t affected as they are directly into bloodstream
Therapeutic range
range that yields beneficial effects with least probability of causing toxicity
Therapeutic level –
within the therapeutic range
Underdosing
below therapeutic range
exerts suboptimal or no pharmacological effect
Overdosing
above therapeutic range
adverse effects, toxicity, or possibly death can occur
Loading dose
larger initial dose to help to achieve therapeutic concentrations rapidly
Maintenance dose
dose to maintain therapeutic concentrations
Half life (t ½)
Time it takes for the concentration of a substance to decrease by half
Longer half-lives imply longer duration of action and longer dosing frequencies
Local Effect
effect to a specific part of the body
Systemic Effect
effect on entire body
Drug dependence
Physiological or psychological adaptation to a drug and cannot function without it
Addiction
Perceived need to use a drug to attain psychological and physical effects of euphoric or mood altering substances
Drug abuse
Use of drugs for purposes other than those prescribed and / or in amounts that were not directed
Can be linked to addiction (but not always)
Tolerance
Decrease in response to the effects of a drug with continued administration
Drug Interactions
4 ‘s.h.a.f.’
smoking
herbal supplements
alcohol
Food
Complementary and Alternative Medicine (CAM)
Herbal and dietary supplements
Homeopathy
Acupuncture
Potentiation
when a drug increases the action of another drug, and the effect is greater than the sum of the effects of each drug used alone
Synergism
joint action of drugs in which their combined effect is more intense or longer in duration than individually
Antagonism
The action of one drug negates the action of a second drug
Addition
the combined effect of two drugs is equal to each drug taken alone
