Pathophysiology and Pharmacology (Unit One)

Pharmacology

the study of drugs and their interactions with living systems.

Pharmacokinetics

Movement of drugs and what happens to the body when the drug is taken

Pharmodynamics

What outcome are we trying to get from a drug; What drugs do for the body.

Drug

any chemical that affects the processes of a living organism.

Pharmacotherapeutics

the application of drugs to prevent or treat diseases and ease suffering.

• Plants

• Animals / Humans

• Minerals

• Chemicals (The major source of drugs)

What are some major sources of drugs?

Chemical

What is the most major source of drugs?

• Chemical

• Generic

• Trade/Brand Name

What are some forms of drugs names?

Chemical Name

Describes the drug's chemical structure

Generic Name

Non-proprietary name, often a simpler name, e.g., ibuprofen, alprazolam.

Trade/Brand Name

Proprietary name given by the manufacturer, e.g., Motrin, Advil, for ibuprofen; Xanax for alprazolam

Prescription Drug

Require a written order from a licensed healthcare provider

• Ex. Levothyroxine: Thyroid Medication

Nonprescription Drug (OTC)

Available for purchase without a prescription.

• Ex. ibuprofen, tylenol

Behind the Counter (BTC)

Nonprescription drugs stored behind the pharmacy counter, requiring pharmacist intervention for purchase.

• Ex. Nonprescription insulin

Controlled Drugs

Substances with a potential for abuse or dependence; their use and distribution are

regulated by the DEA, requiring a DEA number for prescribing

• Ex. Heroin, Xanax, Codeine

Recreational Drugs

Used for non-medical purposes, often illegal and unregulated.

• Ex. Alcohol, Cannabis

Yes

For safety and interaction checks, should we treat dietary supplements like medications?

• Effective

• Safe

• Selective

• Reversible

• Predictable

• Free from Interactions

• Affordable

• Chemically Stable

Characteristics of an ideal drug: Produces the desired therapeutic response.

Effective

One of the characteristics of an ideal drug;

Safe

One of the characteristics of an ideal drug; Does not produce harmful effects, even at high doses or with prolonged use

Selective

One of the characteristics of an ideal drug; Produces only the desired effect without unwanted side effects.

Reversible

One of the characteristics of an ideal drug; Its effects can subside within an appropriate time frame

Reversible

One of the characteristics of an ideal drug; Its effects can subside within an appropriate time frame.

Predictable

One of the characteristics of an ideal drug; Provides consistent and reliable effects across patients

Free from Interaction

One of the characteristics of an ideal drug; Does not adversely interact with other drugs, foods, or substances

Affordable

One of the characteristics of an ideal drug; Accessible and economically viable for patients.

Chemically Stable

One of the characteristics of an ideal drug; Maintains its integrity and potency over time and under various conditions

U.S. Pharmacopeia (USP)

Sets standards for drug quality, purity, strength, and consistency; To be used when one needs to verify quality standards, testing procedures, or purity rules for medicines, dietary supplements, or food ingredients

• Merged with NF

National Formulary

Lists officially recognized drugs; To be used when you need to check safe, up-to-date facts about giving, administering, or prescribing medicines.

• Merged with USP

Physician’s Desk Reference (PDR)

Provides comprehensive drug information (with pictures) from manufacturers. To be used to check official FDA-approved prescribing details, dosages, adverse reactions, and contraindications

Nursing Drug Handbook

Tailored for nursing practice, including administration guidelines and nursing implications. Used to ensure safe medication administration, verify accurate dosing, and guide clinical decision-making

Pure Food and Drug Act of 1906

the first major U.S. federal law to ban the interstate traffic of adulterated or mislabeled food and drugs.

Food, Drug, and Cosmetic Act of 1938

Law giving the Food and Drug Administration authority to oversee the safety of food, drugs, medical devices, and cosmetics

Durham-Humphrey Amendment of the 1938 Act

to create a clear legal distinction between prescription (legend) and over-the-counter (OTC) drugs, ensuring that medications unsafe for self-medication were only dispensed under medical supervision

Kefauver-Harris Amendment of the 1938 Act

law that updated the Federal Food, Drug, and Cosmetic Act of 1938 to require drug companies to prove that their medicines are both safe and effective before selling them

Controlled Substance act of 1970

serves as the federal foundation for U.S. drug policy by regulating the manufacture, distribution, importation, and possession of specific drugs and substances

Orphan Act of 1983

law designed to encourage pharmaceutical companies to develop safe and effective treatments for rare diseases.

Food and Drug Administration Modernization Act

reforms the regulation of drugs, medical devices, and food by speeding up review times and updating FDA procedures

Food and Drug Administration (FDA)

Regulates the development, manufacturing, and marketing of medicines, food, medical products, and cosmetics to ensure their safety and efficacy.

Drug Enforcement Agency (DEA)

Enforces the controlled substances laws and regulations of the United States

Centers for Disease Control (CDC)

Monitors disease threats, conducts research, and provides health information

American Nursing Association (ANA)

Advocates for the nursing profession and sets standards for nursing practice

State Board of Nursing

Sets and enforces standards for nursing education and practice within each state

• Malfeasance

• Misfeasance

• Nonfeasance

What are the three legal risks in Medication Administration?

Malfeasance

Wrong route

• Example: Ordered IV but given IM/subQ → loss of efficiancy/tissue injury

Misfeasance

Wrong drug/dose

• Example: Look‑alike/sound‑alike: clonidine (BP) vs Klonopin/clonazepam; decimal errors

Nonfeasance

Forgot/omitted dose or unsafe delay → therapeutic failure/withdrawl

• Preclinical Research

• Phase 1: Clinical Trial

• Phase 2: Clinical Trial

• Phase 3: Clinical Trial

• Post-market Surveillance

What are the parts of the drug development process?

Preclinical Research

First phase of Drug Development; Initial laboratory testing on cells and animals; followed by an Investigational New Drug (IND) application if promising

Phase One: Clinical Trial

Second Phase of Drug Development: Drug administered to a small group of healthy volunteers to assess safety, dosage and pharmacokinetic profile

Phase Two: Clinical Trial

Third Phase of Drug Development; Drug administered to several hundred patients with the target disease to evaluate effectiveness and assess safety

Phase Three: Clinical Trial

Fourth phase of Drug Development; Drug administered to thousands of patients with the target disease to confirm effectiveness, monitor side effects, compare to common treatments, and collect data for widespread use

Postmarket Surveillance

Ongoing monitoring of the drug's safety and effectiveness once it is on the market to detect any harmful effects overtime

• Right Patient- two identifiers

• Right Medication- three checks for medication

• Right Dose

• Right Time

• Right Route

What are the five rights?

• Assessment

• Evaluation

• Documentation

• Refusal

• Education

What are some additions to the five rights?

• Goals of drug therapy

• Mechanism of drug action

• Expected effect

• Proper administration techniques

• Contraindications

• Assess responses

• Client education

What are the nursing responsibilities specific to drug therapy?

• Pharmaceutic

• Pharmacokinetic

• Pharmacodynamic

What are the phases of drug action?

Pharmaceutic Phase

Occurs with oral medications; involves the breakdown of the dosage form and dissolution of the drug. This phase must occur first for oral drugs

Pharmacokinetic Phase

What the body does to the drug. This involves the processes of Absorption, Distribution, Metabolism, and Excretion (ADME)

Pharmacodynamic Phase

What the drug does to the body. This describes the drug's mechanism of action and its effects at the cellular level.

Absorption

First phase of the Pharmacokinetic Phase of Drug Action; The movement of a drug from its site of administration into the bloodstream

• Stomach, Small Intestines

Distribution

Second phase of the Pharmacokinetic Phase of Drug Action; The movement of the drug from the blood to various body tissues and its target sites

• Bloodstream

Metabolism

Third phase of the Pharmacokinetic Phase of Drug Action; The chemical alteration of the drug; primarily by enzymes, to make it more water-soluble for excretion or to activate/inactivate it.

• Liver

Excretion

The removal of the drug and its metabolites from the body

• Kidneys, Bladder, Large Intestines/Colon

• Blood flow

• Surface Area

• GI Motility

• pH Partitioning

• Bioavailability

Factors that influence absorption rate?

Blood Flow (Absorption)

Areas with greater blood flow (e.g., highly vascular areas) generally have faster absorption rates. Applying heat increases blood flow, while cold decreases it

Surface Area (Absorption)

A larger surface area (e.g., the small intestine with its villi) allows for faster absorption

GI Motility (Absorption)

The longer the drug's contact time with the absorptive surface, the greater the absorption.

pH Partitioning (Absorption)

Acidic drugs are more fat-soluble in acidic environments, while alkaline drugs are more fat-soluble in alkaline environments. This impacts where they are best absorbed along the GI tract

Bioavailability (Absorption)

The amount of drug that reaches the systemic circulation in an unchanged form after administration

Passive and Active

What are the two main drug transport systems?

Passive Transport

No energy required, diffusion, lipid-soluble/non-ionized drugs are absorbed faster in the GI Tract via _____ diffusion

• Diffusion- Movement of drug molecules from an area of higher concentration to a lower concentration.

Active Transport

Requires energy, requires a carrier for transport to move drugs across membranes, Pinocytosis

• Carrier = enzyme or protein, examples

• Pinocytosis- A process where the cell engulfs the drug molecule.

Enteral and Parenteral

What are the two routes of administration?

Enteral Route

via the GI Tract

• Oral (PO)- Easiest, cheapest, safest, allows self-administration. However, it's less reliable, and drugs can be inactivated or altered by GI pH and enzymes. All oral drugs are subject to the first-pass effect

• Sublingual (SL)

• Buccal

• Nasogastric (NG)

Parenteral Route

Bypassing the GI Tract

• Intravenous (IV)- Provides 100% bioavailability. Allows for large volumes and irritant drugs. However, it is expensive, irreversible, and carries higher risks (e.g., infection, embolism).

• Intramuscular (IM)

• Subcutaneous- Injected under the skin; absorption is generally slower than IM/IV, can be painful, and has potential for tissue damage

First-Pass Effect

A pharmacological process where the concentration of an oral medication is greatly reduced by the liver and gut wall before it ever reaches the general bloodstream

• Usually experienced by PO medications

Topical Administration

Applied to skin or mucous membranes (e.g., eye/ear drops, vaginal suppositories). Provides a constant slow onset; absorption rate varies based on form and application, with special considerations for pediatric patients and individuals with damaged skin

Inhalation

Administered via the respiratory tract (e.g., nebulizers, metered-dose inhalers (MDI), Narcan).

Local Effect of Medication

Affects one specific body system or organ (e.g., topical cream for a skin rash).

Systemic Effects of Medication

Has the potential to affect multiple body systems or organs as it enters the bloodstream (e.g., oral antibiotic).

Distribution

The reversible movement of a drug from the systemic circulation into the interstitial and intracellular fluids, eventually reaching its target cells.

• Blood Flow

• Solubility

• Drug’s Affinity to Certain Tissues

• Physiological Barriers

What is distribution influenced by?

Blood Flow (Distribution)

Areas with rich blood supply (e.g., brain, heart, major arteries, lungs, kidneys, liver) receive drugs more rapidly than areas with poor perfusion (e.g., shock, hypotension, peripheral vascular disease abscesses, tumors).

Solubility (Distribution)

Lipid-soluble drugs can easily cross cell membranes and distribute widely into tissues, including fat tissue.

Drug’s Affinity to Certain Tissues (Distribution)

Some drugs have a strong attraction to specific tissues, leading to accumulation (e.g., tetracyclines in bones, B-vitamins, iodine).

Physiological Barriers (Distribution)

Specialized barriers that limit drug access to certain areas

• Blood-Brain Barrier

• Placental Barrier

Albumin

the main protein that drugs bind to in the blood

Free Drugs

unbound, circulate freely, are pharmacologically active, bind to target receptors to produce a desired response, and are eventually excreted.

• If bound, they are can not exert their effects or be metabolized/excreted

Blood-Brain Barrier (BBB)

A highly protective barrier that restricts the passage of substances into the brain. It is very efficient, and generally, only fat-soluble drugs can pass.

Placental Barrier

A membrane between maternal and fetal blood that can be crossed by many drugs posing risks to the fetus, especially during the first and third trimesters. The FDA uses pregnancy risk categories to classify drug safety during pregnancy.

Metabolism

The chemical alteration of a drug by the body, primarily in the liver, often converting lipid-soluble drugs into more water-soluble forms for easier excretion.

• Disease State

• Enzyme Induction

• Age

• Food/Drug Interactions

• Genetics

• Environment

Factors influencing Metabolism?

Disease State (Metabolism)

Liver diseases (e.g., cirrhosis) or heart failure can impair the liver's metabolic capacity

Enzyme Induction (Metabolism)

Some drugs or substances can cause the liver to produce more metabolizing enzymes, leading to faster metabolism of other drugs.

Age (Metabolism)

Metabolism can be significantly different in the elderly (deteriorated function) and infants (immature liver enzymes)

Food/Drug Interaction (Metabolism)

Certain foods (e.g., grapefruit) can inhibit drug-metabolizing enzymes, leading to higher drug levels

Genetics (Metabolism)

Individual genetic variations can lead to differences in metabolic enzyme activity, affecting drug response

Environment (Metabolism)

Factors like cigarette smoke exposure or stress can influence drug metabolism.

Kidneys

What are the most significant organ for drug excretion?