Pharmacology Quiz: Drug Mechanisms and Effects

Module 1B Introductory Topics for Pharmacology

• Course Instructor: Cathy Magowan, PhD, MSN, RN
• University: D'Youville University
• Course Number: NUR 320
• Course Title: Pathophysiology/Pharmacology for Nurses
• Semester: Spring 2025

Learning Objectives

• Understand drug action concepts and principles
• Identify developmental and cultural considerations in pharmacology
• Identify developmental and cultural considerations of drug administration
• Understand relevant pharmacology terminology and guidelines

Chapter 1 Introduction to Drugs

• Adverse Effects (Side Effects): Undesired effects of a medication, ranging from unpleasant to dangerous.
• Brand Name: The name given by the pharmaceutical company (trade name/proprietary name).
• Generic Name: The original name given to a drug when developed.
• Off-Label Use: Using a drug for a purpose not specified in the approved indication (labeling).
• Over-the-Counter (OTC) Drugs: Medications available without a prescription.
• Pharmacology: The study of the biological effects of chemicals.
• Pharmacotherapeutics: The branch of pharmacology studying drugs for disease treatment, prevention & diagnosis.
• Teratogenic: Medications that cause harm to a developing fetus during pregnancy.

Drug Testing Phases

• Phase I (one): Pilot study with a small group. Usually healthy volunteers.
• Phase II (two): Clinical study with select physicians. Conducted with patients who have the disorder the drug is intended for.
• Phase III (three): Larger study with patients who have the disorder.
• Phase IV (four): Continuous evaluation after release. Looking for long term data and reporting effectiveness.
• Preclinical trials: Initial tests on chemicals thought to have therapeutic potential, before human trials (in vitro and in vivo).

Sources of Medications

• Plant Sources:
  • Ricinus communis: Castor oil, seeds.
  • Digitalis purpurea: Digitalis leaf.
  • Papaver somniferum: Opium, Morphine, MS Contin, Codeine.
• Element Sources:
  • Aluminum: Antacid, phosphate urinary stone prevention.
  • Fluorine (as fluoride): Dental cavity and osteoporosis prevention.
  • Gold: Rheumatoid arthritis treatment.
  • Iron: Iron deficiency anemia treatment.

Legal Regulation of Drugs

• Food and Drug Administration (FDA): Responsible for regulating drug development and sales.
• Pure Food and Drug Act (1906): The first legislation to attempt to reduce mislabeling. Required labeling as a way to eliminate misleading or false claims.
• Federal Food, Drug, and Cosmetic Act (1938): Mandated toxicity tests, procedures for introducing new drugs, and recall mechanisms for drugs.
• Comprehensive Drug Abuse Prevention and Control Act (1970): Defined drug abuse, classified drugs by abuse potential and established strict controls on distribution, storage, and use.
• Local & State Regulations: Exist in addition to federal regulations

Safety During Pregnancy

• Category A: Appropriate human studies show no risk.
• Category B: Insufficient human studies, but animal research suggests safety, or animal research shows issues, but human research shows safety.
• Category C: Insufficient human studies, but animal studies show problems, or no animal studies and insufficient human studies
• Category D: Human studies (with or without animal research) show fetal risks, but the drug is often vital to some women for treatment.
• Category X: Fetal risks are evident; no situations where the risk/benefit justifies use.

Controlled Substances

• Schedule I: High potential for abuse, no currently accepted medical use.
• Schedule II: High potential for abuse, but accepted medical use.
• Schedule III: Less potential for abuse than Schedule II, accepted medical use.
• Schedule IV: Less potential for abuse than Schedule III, accepted medical use.
• Schedule V: Less potential for abuse than Schedule IV, accepted medical use.

Other Drug Categories

• Generic Drugs: Produced by companies focused on manufacturing. Must have identical strength. Often as effective as brand-name drugs, but usually less expensive.
• Orphan Drugs: Not profitable for standard drug companies to make.
• Over-the-Counter (OTC) Drugs: Available without prescriptions, used for self-treatment.

Learning Objectives (Chapter 2 Drugs and the Body)

• Describe how body cells respond to medications.
• Outline dynamic equilibrium, determining the actual concentration of a drug in the body.
• List six factors that influence drug effectiveness.
• Define drug interactions (drug-to-drug, drug-to-alternative therapy, drug-to-food, and drug-to-laboratory test).

Terms to Know (Pharmacology)

• Pharmacodynamics: How a chemical (drug) affects the body.
• Pharmacokinetics: How the body processes a drug (including absorption, distribution, metabolism, excretion.)
• Pharmacogenomics: Variations in how people respond to drugs based on genetics.
• Absorption: How a drug enters the bloodstream.
• Distribution: How the drug is transported throughout the body.
• Metabolism (Biotransformation): How the body breaks down the drug.
• Excretion: How the drug leaves the body.
• Critical Concentration: The level a drug needs to reach in the tissues to cause a desired effect.
• First-Pass Effect: Drugs that are absorbed into the body from the gastrointestinal tract (e.g., stomach) first circulate to the liver for metabolism. Potentially reduces the amount of drug that is reaching its target areas.
• Half-Life: The time it takes for the amount of a drug in the body to diminish to half of its original level.
• Loading Dose: Higher initial dose to produce the therapeutic drug level sooner.
• Placebo Effect: The documented effect of the mind on drug therapy.

Pharmacodynamics

• Agonists: Replace or act as substitutes for missing chemicals. Example: insulin.
• Selective Toxicity: A drug that is aimed at damaging only foreign cells.
• Antagonists: Depressing or slowing down cellular activities. Example: antiinflammatories.
• Interfering with foreign cell functioning: Example: Antibiotics.

Pharmacokinetics (Again, for clarity)

• Critical Concentration: The drug level where it is effective within the body.
• Therapeutic Index: The ratio of a drug's toxic concentration to its therapeutic concentration.
• Loading Dose: Administering a higher initial dose to quickly achieve a therapeutic concentration.

Absorption (cont.)

• Routes of Administration & Factors Influencing Absorption:

  • Intravenous (IV): Immediate bloodstream entry.
  • Intramuscular (IM): Absorption into muscles.
  • Subcutaneous: Absorption into tissues beneath the skin.
  • Oral (PO): Absorption from the gastrointestinal tract.
  • Rectal (PR)/Vaginal: Absorption via membranes.
  • Mucous Membranes (SL, buccal): Absorption through the layers of the mouth.
  • Topical/Intradermal (skin): Absorption through the skin.
  • Inhalation: Absorption through the lungs.

Distribution

• Tissue Perfusion: The flow of blood to a tissue.
• Protein Binding: Drug binding to proteins in the blood.
• Blood-Brain Barrier: This barrier system prevents many drugs from reaching the central nervous system, restricting drug access to the brain.
• Placenta and Human Milk: Drugs can pass through the placenta and into breast milk.
• Biotransformation (Metabolism): Drugs may undergo transformation within the body, sometimes affecting their efficiency.
• First-pass effect: When drugs metabolized in the liver prior to reaching the rest of the body; may result in decreased efficiency.
• Hepatic Enzyme System: System of enzymes in the liver that works to metabolize many substances.
• Half-Life: The length of time for a drug to reach half of its peak level and for that to reduce again to half its level, and continuing this pattern throughout the body's handling of the substance.

Excretion

• Excretion Routes: Kidneys, liver, lungs, intestines. (Different organs excrete different substances).

Factors Influencing Drug Effects

• Weight: Heavier people may need higher doses.
• Age: Metabolism rates and effectiveness can vary by age.
• Sex: Females may have different responses to medications, partly due to differences in fat tissue quantities between men and women.
• Psychological Factors: A person's attitude about a drug may affect how it works.
• Genetic Factors: Genetics play a large factor in how a drug affects an individual.
• Immunological Factors: Allergies and diseases can cause a variance in drug responses.
• Environment: Temperature, noise, and other environmental factors might influence drug effects.
• Pathological Factors: Pre-existing conditions affect how a drug will interact and how it will be handled.

Drug-Drug or Drug-Alternative Therapy Interactions

• Site of absorption: One medication may prevent or increase the absorption of another.
• Distribution: One drug might compete with another for protein binding, preventing it from reaching its site of action.
• Biotransformation: One drug may affect the metabolism of another, potentially leading to toxic drug levels and side effects.
• Excretion: Competing for excretion sites reduces the effectiveness of one or both.
• Site of action: One drug may be an antagonist to the other, reducing or preventing a desired effect.

Additional Questions and Answers/Key Concepts:

(See specific questions in the provided text for concise answers. These concepts are likely to be covered in the answers.)

• Drug Metabolism
• Drug Interactions
• Drug Toxicity
• Drug Safety (Patient Safety)
• Nursing Process
• Clinical Judgement
• Pharmacokinetic and Pharmacodynamic Principles
• Assessment and Evaluation

Test your knowledge on key pharmacological concepts, including drug absorption, distribution, and the significance of the blood-brain barrier. This quiz covers essential topics such as the first-pass effect, half-life, and selective toxicity. Get ready to explore the intricate world of drug interactions and therapeutic applications.