Introduction to Nursing Pharmacology Flashcards
A tablet or capsule taken by mouth goes through three phases—_____________________________________________ —as drug actions occur
pharmaceutic, pharmacokinetic, and pharmacodynamic
In the ________________________, the drug becomes a solution so that it can cross the biologic membrane.
pharmaceutic phase
there is no pharmaceutic phase when the drug is administered parenterally by
subcutaneous (subQ), intramuscular (IM), or intravenous (IV) routes
four processes of pharmacokinetic phase
absorption, distribution, metabolism (or biotransformation), and excretion (or elimination)
In the pharmacodynamic phase, a _______________________________ results
biologic or physiologic response
Approximately ______________ of drugs are taken by mouth
80%
The first phase of drug action
Pharmaceutic Phase
Pharmaceutic Phase is also called
dissolution
a process where a drug in solid form must disintegrate into small particles to dissolve into a liquid.
dissolution
are fillers and inert substances that are used in drug preparation to allow the drug to take on particular size and shape and to enhance drug dissolution.
Excipients
is the breakdown of a tablet into smaller particles
Disintegration
The two pharmaceutic phases are:
disintegration and dissolution
is the time it takes the drug to disintegrate and dissolve
to become available for the body to absorb it
Rate limiting
what capsules/tablets should not be crushed?
Enteric-coated tablets or capsules and sustained-release (beaded) capsules
factors that affect rate limiting
- Gastric Acidity
- Age - very young and elderly
- Enteric-coated tablets
- Food
is the process of drug movement to active drug action
Pharmacokinetic
is the movement of drug particles from the GI tract to
body fluids by passive absorption, active absorption, or pinocytosis
Absorption
factors that affect absorption
- Surface area of the small intestine
- Protein-based drugs
occurs mostly by diffusion
Passive absorption
- requires a carrier, such as an enzyme or protein, to
move the drug against a concentration gradient. - Energy is required for active absorption.
Active absorption
a process by which cells carry drug across membrane by
engulfi ng the drug particles
Pinocytosis
The three major processes for drug absorption through the gastrointestinal membrane are:
passive absorption, active absorption, and pinocytosis
Drugs that are _________________________ are absorbed faster than ________________________
lipid soluble and nonionized; water-soluble and ionized drugs
what factors affect drug absorption in the pharmacokinetic phase?
Blood flow, pain, stress, hunger, fasting, food and pH
medication routes that absorb drugs from fastest to slowest
Intramuscular (Deltoid) > Intramuscular (Gluteal) > Subcutaneous
The process in which the drug passes to the liver first.
First Pass Effect
_______________________ are given orally while
_______________________ are not given orally because they have extensive first-pass effect.
Warfarin and Morphine Sulfate; Lidocaine and some Nitroglycerins
is a subcategory of absorption
Bioavailability
It is the percentage of the administered drug dose that reaches the systemic circulation
Bioavailability
The percentage of bioavailability for the oral route is always ___________________-
less than 100%
The percentage of bioavailability for the IV route it is
100%
Factors that alter bioavailability include:
(1) the drug form (e.g., tablet, capsule, sustained-release, liquid, transdermal patch, rectal suppository, inhalation)
(2) route of administration (e.g., oral, rectal, topical, parenteral)
(3) GI mucosa and motility
(4) food and other drugs
(5) changes in liver metabolism caused by liver dysfunction or inadequate hepatic blood flow
is the process by which the drug becomes available to body
fluids and body tissues
Distribution
factors that affect Distribution
- blood flow
- affinity to the tissue
- protein-binding effect
- drug dose and its concentration
Drugs that are greater than 89% bound to protein are known as
highly protein-bound drugs
drugs that are 61% to 89% bound to protein are
moderately highly protein-bound drugs
drugs that are 30% to 60% bound to protein are
moderately protein-bound
drugs that are less than 30% bound to protein are
low protein-bound drugs
Highly protein-bound drugs
89% and above
moderately highly protein-bound drugs
61% - 89%
moderate protein-bound drugs
30% - 60%
low protein-bound drugs
Less than 30%
drugs not bound to protein
free drugs
Only _________________ are active and can cause a
pharmacologic response.
FREE DRUGS
factors affecting/hinder drug distribution of free drugs:
- Two highly protein-bound drugs are given
- low protein levels
- clients with liver and kidney disease
- malnourished
- elderly
- abscesses
- exudates
- body glands
- tumors
is the primary site of metabolism
Liver
inactivates most of the drugs and are then converted or
transformed to inactive metabolites or water-soluble substances for
excretion.
Liver enzymes
Decreased drug metabolism results to excess drug accumulation which can lead to
toxicity
is the time it takes for one half of the drug concentration to be eliminated
half-life (t1/2)
the main route of drug elimination is through the ______________________
kidneys (urine)
the kidney filters:
free, unbound drugs; water soluble drugs and drugs that are
unchanged
other routes of drug elimination include:
- hepatic metabolism
- bile
- feces
- lungs
- saliva
- sweat
- breast milk
influences drug excretion
Urine pH
promotes elimination of weak acid drugs and vice versa
Acid urine
Most accurate to determine renal function
Creatinine Clearance
is the study of drug concentration and its effects on
the body
Pharmacodynamic
Drug response can cause a ____________________________
effect
primary (desirable) or secondary (desirable or undesirable)
primary effect
desirable
secondary effect
desirable or undesirable
is the relationship between the minimal versus the maximal amount of drug dose needed to produce the desired drug response
Dose Response and Maximal Efficacy
the dose of medication required to produce a particular response
Potency
A drug that is __________________ will produce a therapeutic effect at a _______________ compared with another drug in the same class
more potent; lower dose
the magnitude of maximum response that can be produced
from a particular drug
Efficacy
From a pharmacotherapeutic perspective, ____________ is almost always more important than ______________
EFFICACY; POTENCY
is the time it takes to reach the minimum effective concentration (MEC) after the drug is administered
Onset of Action
occurs when the drug reaches its highest blood plasma concentration.
Peak Action
is the length of time the drug has a pharmacologic effects
Duration of Action
The time-response curve evaluates three parameters of drug action:
(1) onset, (2) peak, and (3) duration
Drug-Binding Sites are primarily on
proteins, glycoproteins, proteolipids, and enzymes
Four receptor families:
a.) Cell membrane-embedded enzymes
b.) Ligand-gated ion channels
c.) G protein-coupled receptor systems
d.) Transcription factors
drugs that produce a response
Agonist
example of Agonist drugs
Isoproterenol
drugs that block a response
Antagonist
example of Antagonist drugs
Ranitidine
drugs that affect various sites and have properties of non-specifi city.
Nonspecific Drugs
drugs that affect at different receptors
Nonselective Drugs
Four Categories of Drug Action
a.) Stimulation or Depression
b.) Replacement
c.) Inhibition or Killing of Organisms
d.) Irritation
example of Stimulation or Depression drugs
Digoxin
example of Replacement drugs
Insulin
example of Inhibition or Killing of Organisms drugs
Antibiotics
example of Irritation drugs
Laxatives
estimates the margin of safety of a drug through the use of a ratio that measures the effective (therapeutic concentration) dose (ED) in 50% of persons or animals and the lethal dose in 50% of animals
Therapeutic Index (TI)
Drugs with a low therapeutic index have a ____________________________. The closer the ratio is to ___, the _________________ the danger of toxicity.
narrow margin of safety; 1; greater
of a drug concentration in plasma should be between the minimum effective concentration in the plasma for obtaining desired drug action and the minimum toxic concentration, the toxic effect.
Therapeutic range (Therapeutic window)
is the highest plasma concentration of drug at specifi c time
Peak Drug Level
is the lowest plasma concentration of a drug, and it measures the rate at which the drug is eliminated.
Trough Level
When immediate drug response is desired, a _______________________ is given to achieve a rapid minimum effective concentration in the plasma.
large initial dose of drug
After a large initial dose, a ________________________ is ordered
prescribed dosage per day
are physiologic effects not related to desired drug effects
Side Effects
Side effects result mostly from drugs that lack
specificity
are more severe than side effects
Adverse Reactions
of a drug can be identifi ed by monitoring the plasma (serum) therapeutic range of the drug.
Toxic Effects or Toxicity
is the effect of a drug action that varies from a predicted drug response because of genetic factors or hereditary infl uence.
Pharmacogenetics
drug tolerance to a frequently repeated administration of a certain drug
Tachyphylaxis
Drug categories that can cause tachyphylaxis include:
narcotics, barbiturates, laxatives, and psychotropic agents
is a psychologic benefi t from a compound that may not have the chemical structure of a drug effect.
Placebo Effect
Absorption is the movement of drug particles from the GI tract to body fluids by _______________________________________________________________
passive absorption, active absorption, or pinocytosis
is required for active absorption
Energy
