Absorption
What happens to a drug from the time it enters the body until it enters the circulating fluid; intravenous administration causes the drug to directly enter the circulating blood, bypassing the many complications of absorption from other routes
Active transport
The movement of substance across a cell membrane against the concentration gradient; this process requires the use of energy
Chemotherapeutic agents
Synthetic chemicals used to interfere with the function of foreign cell populations; this term is frequently used to refer to the drug therapy of neoplasms, but it also refers to drug therapy affecting foreign cells
Critical Concentration
the concentration a drug must reach in the tissues that respond to the particular drug to cause the desired effect
Distribution
Movement of a drug to body tissues; the places where a drug may be distributed depend on the drug's solubility, perfusion of the area, cardiac output and binding of the drug to plasma proteins
Enzyme Induction
process by which the presence of a chemical that is biotransformed by a particular enzyme system in the liver causes increased activity of that enzyme system
Excretion
Removal of a drug from the body; primarily occurs in the kidneys but can occur through the skin, lungs, bile or feces
First-pass effect
A phenomenon in which drugs given orally are carried directly to the liver after absorption where they may be largely inactivated by liver enzymes before they can enter the general circulation; oral dugs frequently are given in higher doses than drugs giv
Glomerular Filtration
the passage of water and water-soluble components from the plasma into the renal tubule
Half-life
The time it takes for the amount of drug in the body to decrease to one-half of the peak level it previously achieved
Passive diffusion
Movement of substances across a semi-permeable membrane with the concentration gradient; this process does not require energy
Pharmacodynamics
The science that deals with interactions between the chemical components of living systems and the foreign chemicals, including drugs, that enter living organisms; the way a drug affects a body
Pharmacogenomics
The study of genetically determined variation in the response to drugs
Pharmacokinetics
The way the body deals with a drug, including absorption, distribution, biotransformation and excretion
Placebo effect
Documented effect of the mind on drug therapy; if a person perceives that a drug will be effective, the drug is much more likely to be effective
Receptor sites
Sites on cell membranes that react with specific other chemicals to cause an effect; a drug may be effective because it reacts with a specific receptor site on particular cells in the body
Selective toxicity
Property of a chemotherapeutic agent that affects only systems found in foreign bodies, without affecting healthy human cells
Drug Actions
Drugs usually work in one of four ways:
1. To REPLACE or act as substitutes for missing chemicals.
2. To INCREASE or stimulate certain cellular activities.
3. To DEPRESS or slow cellular activities.
4. To INTERFERE with the functioning of foreign cells, such as invading microorganisms or neopla
Pharmacodynamics is
the process by which a drug works on the body.
Drugs may work by
replacing a missing body chemical, by stimulating or depressing cellular activity, or by interfering with the functioning of foreign cells.
Drugs are thought to work by reacting with
specific receptor sites or by interacting with enzyme systems in the body.
The actual concentration that a drug reaches in the body results from a dynamic equilibrium involving several factors:
1. Absorption from the site of entry
2. Distribution to the active site
3. Biotransformation (metabolism) in the liver
4. Excretion from the body
Pharmacokinetics is
the study of how the body deals with a drug.
The concentration of a drug in the body is determined by
the balance of absorption, metabolism, distribution, and excretion of the drug.
In determining the dosage, route, and appropriate timing of a drug dose, what has to be considered?
the pharmacokinetics of that drug have to be considered.
Factors Affecting the Body's Response to a Drug
Weight
Age
Gender
Physiological factors�diurnal rhythm, electrolyte balance, acid-base balance, hydration
Pathological factors�disease, hepatic dysfunction, renal dysfunction, gastrointestinal dysfunction, vascular disorders, low blood pressure
Genetic fa
Chemotherapeutic agents are drugs that
a. are used only to treat cancers.
b. replace normal body chemicals that are missing because of disease.
c. interfere with the functioning of foreign cells, such as invading microorganisms or neoplasms.
d. stimulate
c. interfere with the functioning of foreign cells, such as invading microorganisms or neoplasms.
Receptor sites
a. are a normal part of enzyme substrates.
b. are protein areas on cell membranes that react with specific chemicals to cause an effect within the cell.
c. can usually be stimulated by many different chemicals.
d. are responsible for all dr
b. are protein areas on cell membranes that react with specific chemicals to cause an effect within the cell.
Selective toxicity is
a. the ability of a drug to seek out a specific bacterial species or microorganism.
b. the ability of a drug to cause only specific adverse effects.
c. the ability of a drug to cause fetal damage.
d. the ability of a drug to attack o
d. the ability of a drug to attack only those systems found in foreign or abnormal cells.
The absorption of a drug taken orally can be affected by
a. the blood flow to muscle beds.
b. the acidity of the gastric juices, often influenced by the presence of food.
c. the weight and age of the patient.
d. the temperature of the peripheral environme
b. the acidity of the gastric juices, often influenced by the presence of food.
Much of the biotransformation that occurs when a drug is taken occurs as part of
a. the protein binding effect of the drug.
b. the functioning of the renal system.
c. the first-pass effect through the liver.
d. the distribution of the drug to the reactive
c. the first-pass effect through the liver.
The half-life of a drug
a. is determined by a balance of all of the factors working on that drug�absorption, distribution, biotransformation, and excretion.
b. is a constant factor for all drugs taken by a patient.
c. is influenced by the fat distribution
a. is determined by a balance of all of the factors working on that drug�absorption, distribution, biotransformation, and excretion.
Jack B. has Parkinson's disease that has been controlled for several years with levodopa. After he begins a health food regimen with lots of vitamin B6, his tremors return, and he develops a rapid heart rate, hypertension, and anxiety. The nurse investiga
a. a drug-laboratory test interaction.
Multiple Response: Select all that apply.
1. When reviewing a drug to be given, the nurse notes that the drug is excreted in the urine. What points should be included in the nurse's assessment of the patient?
a. The patient's liver function tests
b. The p
c. The patient's renal function tests
d. The patient's fluid intake
e. Other drugs the patient might be taking that could affect the kidney
Multiple Response: Select all that apply.
When considering the pharmacokinetics of a drug, what points would the nurse take into consideration?
a. How the drug will be absorbed
b. The way the drug affects the body
c. Receptor site activation and suppressi
a. How the drug will be absorbed
d. How the drug will be excreted
e. How the drug will be metabolized or biotransformed
f. The half-life of the drug
Multiple Response: Select all that apply.
Drug-drug interactions are important considerations in clinical practice. When evaluating a patient for potential drug-drug interactions, what will the nurse be considering?
a. Bizarre drug effects on the body
b.
b. The need to adjust drug dosage or timing of administration to ensure effective drug therapy because of the actions of one drug on the other
e. Increased adverse effects because of the action of both drugs in the body
f. The use of herbal or alternative
._____________________ describes how drugs affect the body.
pharmacodynamics
_____________________ describes how the body acts on drugs.
pharmacokinetics
Drugs that interfere with the functioning of foreign cells, such as invading microorganisms or neoplasms, are called_____________________.
chemotherapeutic agents
The amount of a drug that is needed to cause a therapeutic effect is called the _____________________.
critical concentration
The dynamic equilibrium that must be considered when administering a drug considers four main factors:____________________,_____________________,___________________, and ___________________.
absorption, biotransformation, distribution, excretion
Drugs taken orally are absorbed from the GI tract and delivered directly to the liver for metabolism. This phenomenon is called the ____________________________.
first-pass effect
The presence of a chemical that is metabolized by a particular enzyme system often increases the activity of that enzyme system. This process is referred to as __________________________.
enzyme induction
The _________________________ of a drug is the time it takes for the amount of drug in the body to decrease to one-half of the peak level it previously achieved.
half-life