GCU NURS 410 WEEK 1 PHARMACOLOGY LATEST REVIEWED
STUDY GUIDE 2026
Absorption What happens to a drug from the time it enters the body until it enters the circulating fluid.
Active transport Movement of substances across a cell membrane that requires energy.
Chemotherapeutic agents Synthetic chemicals that interfere with the functioning of foreign cell
populations, causing cell death; used for neoplasms and any foreign cell.
Critical concentration The concentration a drug must reach in the target tissues to cause the
desired therapeutic effect.
Distribution Movement of a drug to body tissues, influenced by solubility, perfusion, cardiac output,
and protein binding.
Enzyme induction When the presence of a chemical increases the activity of an enzyme system.
Excretion Removal of a drug from the body through the kidneys, skin, lungs, bile, or feces.
First-pass effect Orally administered drugs go to the liver first, where they may be inactivated before
reaching general circulation.
Glomerular filtration Passage of water and water-soluble components from plasma into the renal
tubule.
Half-life Time it takes for the amount of drug in the body to decrease to one half of its peak level.
Hepatic microsomal system Liver enzymes responsible for the biotransformation (metabolism) of
chemicals, including drugs.
Loading dose A higher-than-usual dose given to quickly reach the drug’s critical concentration.
Passive diffusion Movement of substances across a semipermeable membrane down the
concentration gradient; does not require energy.
Pharmacodynamics How a drug affects the body; interactions between living systems and foreign
chemicals.
Pharmacogenomics Study of genetically determined variations in drug response.
Pharmacokinetics How the body acts on a drug: absorption, distribution, metabolism, and
excretion. Placebo effect Effect of the mind on drug therapy; belief in a drug increases its
effectiveness.
Receptor sites Specific areas on cell membranes that react with certain chemicals to cause an effect.
Selective toxicity Ability of a chemotherapeutic agent to affect only foreign cells without harming
human cells.
,Therapeutic index Ratio comparing the toxic concentration of a drug to the effective concentration.
, Key Points
• Drugs come from natural sources (plants, animals, inorganic compounds)
and synthetic sources.
• FDA regulates drug development for safety and efficacy.
• Phases of drug development
1. Preclinical: animal testing
2. Phase I: healthy volunteers
3. Phase II: patients with the disease
4. Phase III: large clinical trials
5. Phase IV: post-marketing surveillance
Rationale
Understanding where drugs come from and how they are tested helps nurses
anticipate risks, educate clients, and recognize early signs of adverse
effects.
1. How body cells respond to drugs that alter their
function Answer
Body cells respond to drugs by binding to receptors, which triggers one of three
actions:
• Stimulate the cell (agonist)
• Block the cell’s normal activity (antagonist)
• Modify how the cell works (partial agonist or enzyme interaction)
Rationale (Memory Trick)
Think of receptors like locks and drugs like keys:
• Agonist = key that opens the lock → turns the cell “ON”
• Antagonist = key that fits but doesn’t turn → blocks the real key
• Partial agonist = key that opens the lock halfway
Cells don’t grow new abilities — drugs only enhance or block what the cell
already can do.
STUDY GUIDE 2026
Absorption What happens to a drug from the time it enters the body until it enters the circulating fluid.
Active transport Movement of substances across a cell membrane that requires energy.
Chemotherapeutic agents Synthetic chemicals that interfere with the functioning of foreign cell
populations, causing cell death; used for neoplasms and any foreign cell.
Critical concentration The concentration a drug must reach in the target tissues to cause the
desired therapeutic effect.
Distribution Movement of a drug to body tissues, influenced by solubility, perfusion, cardiac output,
and protein binding.
Enzyme induction When the presence of a chemical increases the activity of an enzyme system.
Excretion Removal of a drug from the body through the kidneys, skin, lungs, bile, or feces.
First-pass effect Orally administered drugs go to the liver first, where they may be inactivated before
reaching general circulation.
Glomerular filtration Passage of water and water-soluble components from plasma into the renal
tubule.
Half-life Time it takes for the amount of drug in the body to decrease to one half of its peak level.
Hepatic microsomal system Liver enzymes responsible for the biotransformation (metabolism) of
chemicals, including drugs.
Loading dose A higher-than-usual dose given to quickly reach the drug’s critical concentration.
Passive diffusion Movement of substances across a semipermeable membrane down the
concentration gradient; does not require energy.
Pharmacodynamics How a drug affects the body; interactions between living systems and foreign
chemicals.
Pharmacogenomics Study of genetically determined variations in drug response.
Pharmacokinetics How the body acts on a drug: absorption, distribution, metabolism, and
excretion. Placebo effect Effect of the mind on drug therapy; belief in a drug increases its
effectiveness.
Receptor sites Specific areas on cell membranes that react with certain chemicals to cause an effect.
Selective toxicity Ability of a chemotherapeutic agent to affect only foreign cells without harming
human cells.
,Therapeutic index Ratio comparing the toxic concentration of a drug to the effective concentration.
, Key Points
• Drugs come from natural sources (plants, animals, inorganic compounds)
and synthetic sources.
• FDA regulates drug development for safety and efficacy.
• Phases of drug development
1. Preclinical: animal testing
2. Phase I: healthy volunteers
3. Phase II: patients with the disease
4. Phase III: large clinical trials
5. Phase IV: post-marketing surveillance
Rationale
Understanding where drugs come from and how they are tested helps nurses
anticipate risks, educate clients, and recognize early signs of adverse
effects.
1. How body cells respond to drugs that alter their
function Answer
Body cells respond to drugs by binding to receptors, which triggers one of three
actions:
• Stimulate the cell (agonist)
• Block the cell’s normal activity (antagonist)
• Modify how the cell works (partial agonist or enzyme interaction)
Rationale (Memory Trick)
Think of receptors like locks and drugs like keys:
• Agonist = key that opens the lock → turns the cell “ON”
• Antagonist = key that fits but doesn’t turn → blocks the real key
• Partial agonist = key that opens the lock halfway
Cells don’t grow new abilities — drugs only enhance or block what the cell
already can do.
