NURS 1550- Pharmacology 1

NURS 1550- Pharmacology 1

Case Study 1

• A nurse is teaching a group of older adult patients about various OTC and herbal therapies.

1. One of the older adult patients asks, “Why do I have to be careful about how much acetaminophen I take?” How will the nurse address this question?

• Padotoxicity, can only take 4 grams a day. If you take too much tylenol it will cause damage to your liver.

1. After finishing the teaching, the nurse overhears an older man talking to his friend. The nurse hears him say, “Rather than taking the prescription medication for my ulcers, I am just going to take over-the-counter medications; they are much cheaper.” Should the nurse intervene?

• Yes, the medications are not necessary the same strengths. Herbal remedies are something that we want to let our patients know that may not be as effective. It may not have medicinal properties or do what it claims to do. Encourage patient to speak to their HCP before those changes.

Case Study 2

• John Jones, a 54-year-old patient with chronic kidney failure and atrial fibrillation, receives a kidney transplant and is treating his mild depression with St. John’s wort.

1. Determine what medications are commonly used for atrial fibrillation and in renal transplantation.

• Things used for atrial fibrillation may interact with the effects of St.John's wart.

1. List the concerns with using immunosuppressants after kidney transplant, the issues with self-medication with St. John’s wort for depression, and the risk of drug interactions with potential herbal remedies and immunosuppressants after transplant.

• Taking immunosuppresents suppress the immune response, and taking St.John’s wort may interfere with the effectiveness of each.

Pharmacology

• A science that draws on information from multiple disciplines, including:
  • Anatomy
  • Physiology
  • Psychology
  • Chemistry
  • Microbiology

Important Terms to Know

• Drug
  • Any chemical that can affect living processes
  • API (active pharmaceutical ingredients) the stuff that causes the reaction
• Pharmacology
  • Study of drugs and their interactions with living systems
• Clinical pharmacology
  • Study of drugs in humans
• Therapeutics
  • Also known as pharmacotherapeutics
  • The use of drugs to diagnose, prevent, or treat disease or to prevent pregnancy

What are the key things you should about a medication?

• Properties of an ideal drug
  • The name (generic or brand) , the dose, chemical makeup, the strength, interaction with other drugs, side effects, what is the therapeutic reponse, how you store it, the route, duration, how ong it takes to work, limitations, nursing considerations, things we need to know to give the drug (IV, Orally, rectually)
• The therapeutic objective
• Factors that determine the inetsnsity of drug responses
  • Age of patient, some dugs affect new borns
• Therapeutics

Three Most Important Properties of an Ideal Drug

1. Effectiveness: Most important property a drug can have
2. Safety: Drug cannot produce harmful effects
3. Selectivity: Drug elicits only the response for which it is given

Additional Properties of an Ideal Drug

• Reversible action
  • Chose one that can revere if something happens
• Predictability
  • “It might do this” “it will do this” choose one with higher predictability
• Ease of administration
  • Orally vs IV
• Freedom from drug interactions
• Low cost
• Chemical stability
  • If you dont store properly it becomes inactive etc
• Simple generic name
  • Tylenol is a brand name, acetaminophen is generic name. Aspirin vs. acetoacetic acid
• However, no drug is ideal…

Therapeutic Objective of Drug Therapy

• To provide maximum benefit with minimum harm

Factors that Detemine the Intensity of Drug Responses

Administration

• Dosage size, route, and timing
• Medication errors
• Patient adherence

Pharmacokinetics

• How much of the administered dose gets to its sites of action
• Impact of the body on drugs

Pharmacodynamics

• Impact of drugs on the body
• Drug-receptor intercation
• Pateints fucntional state
• Placebo effects

Sources of individual variation

• Physiologic variables
• Pathologic variables
• Genetic variables
• Drug interactions

Four Major Pharmacokinetic Processes

• Drug absorption
• Drug distribution
• Drug metabolism
• Drug excretion

Application of Pharmacology in Nursing Practice

CNO Best Practice Regarding Medication Administration

Nursing Responsibilities in Medication Administration

• Correct administration, without additional interventions, cannot ensure that treatment will result in the therapeutic objective
• participate in a system of checks and balances designed to promote beneficial effects and to minimize harm to patients
• Know what medications are appropriate for the patient, What drugs are contraindicated for the patient, consequences of the interactions between the drug and the patient
• The nurse’s role as advocate
  • Last line of defense for the patient
  • Ethically and legally unacceptable to administer a drug that is harmful to the patient, even though the medication has been prescribed by a licensed prescriber and dispensed by a licensed pharmacist

Applying Pharamacology in Patient Care

• Two major areas in which pharmacologic knowledge can be applied:
  • Patient care
  • Patient education
    • What health teachin needed to be provided to the patient
    • Ask permission, explain what your doing, education (use your walker this way)

Patient Care

1. Pre-administration assessment

• Get a baseline
• Why it was prescribed
• If anything has changed
• Last administration
• Double-check allergies or complications to giving it

1. Dosage and administration

• It makes sense for my patient

1. Evaluating and promoting therapeutic effects

• What the effects are (pain medication, decrease pain)

1. Minimizing adverse effects
2. Minimizing adverse interactions

• Dont give meds that may have an intercation with other things (vitamin K and warfarin)

1. Making PRN decisions

• Refers to administration of prescription as situation calls for

1. Managing toxicity

Patient Education

• Drug name and therapeutic category
• Dosage size
• Dosing schedule
• Route and technique of administration
• Expected therapeutic response and when it should develop
• Nondrug measures to enhance therapeutic responses
• Duration of treatment
• Method of drug storage
• Symptoms of major adverse effects and measures to minimize discomfort and harm
• Major adverse drug-drug and drug-food interactions
• Whom to contact in the event of therapeutic failure, severe adverse reactions, or severe adverse interactions

Nursing Process

• Assessment
• Analysis: Nursing diagnoses
• Planning
• Implementation (Intervention)
• Evaluation

Pre-administration Assessment

• Collection of baseline data to evaluate therapeutic effects
• Collection of baseline data to evaluate adverse effects
• Identification of high-risk patients
• Assessment of the patient’s capacity for
  Self-care

Analysis and Nursing Diagnoses

• Three objectives:
  • Judge the appropriateness of the prescribed regimen
  • Identify potential health problems that the drug might cause
  • Determine the patient’s capacity for self-care

Planning

• Defining goals
• Setting priorities
• Identifying specific interventions
• Drug administration
• Interventions to enhance therapeutic effects
• Interventions to minimize adverse effects
• Patient education
• Establishing objective criteria for evaluation

Implementation

• Drug administration
• Patient education
• Interventions to promote therapeutic effects
• Interventions to minimize adverse effects

Evaluation

• Therapeutic responses
• Adverse drug reactions and interactions
• Adherence to the prescribed regimen
• Satisfaction with treatment

Kinesiology Pharmacology Case Study

• CY CHAN is a 43-year-old man with known history of hypertension on medication under good control. He works as a construction site labourer. He smokes one and a half pack of cigarettes per day, and has done so for over 25 years. His father died from a heart attack at age 60. CY has no signs and symptoms of cardiorespiratory disease. He has just completed a body checkup and the report showed body height of 173cm and body weight of 80kg, whereas blood test showed total cholesterol was found to be 8 mmol/L and fasting glucose of 5.4 mmol/L. You are going to suggest CY to perform regular aerobic and muscle-strengthening exercises as some primary preventive measures for future cardiovascular events. Before that, you would like to stratify his risk to see if he should need further medical workup or exercise testing before increasing his physical activity level
• What risk stratification category is Mr. CHAN in?
• CY CHAN is a 43-year-old man with known history of hypertension on medication under good control. He works as a construction site labourer. He smokes one and a half pack of cigarettes per day, and has done so for over 25 years. His father died from a heart attack at age 60. CY has no signs and symptoms of cardiorespiratory disease. He has just completed a body checkup and the report showed body height of 173cm and body weight of 80kg, whereas blood test showed total cholesterol was found to be 8 mmol/L and fasting glucose of 5.4 mmol/L.
• You are going to suggest CY to perform regular aerobic and muscle-strengthening exercises as some primary preventive measures for future cardiovascular events.
• Before that, you would like to stratify his risk to see if he should need further medical workup or exercise testing before increasing his physical activity level
• What risk stratification category is Mr. CHAN in?

Drug Devleopment, Names, and Information

• New drug development
• Drug names
• Over-the-counter drugs
• Sources of drug information

New Drug Development

• The randomized controlled trial
  • Use of controls
  • Randomization
  • Blinding
• Preclinical testing
• Clinical testing
  • Phase I
  • Phases II and III
  • Phase IV: Post marketing surveillance
• Limited information about the majority of people:
  • Women
  • Children
• Failure to detect all adverse effects

Which Name to Use: Generic or Trade?

• Use of drug names
  • Written and oral communication about medicines
  • Labeling medication containers
• The little problems with generic names
  • More complicated than trade names
• The big problems with trade names
  • Single drug can have multiple trade names
  • U.S. drugs and drugs outside the United States may have different active ingredients
  • Products with the same trade name may have different active ingredients
  • For example, Kaopectate
• Generic products versus brand-name products
  • Are generic products and brand-name products therapeutically equivalent?
  • Would a difference between brand-name and generic products justify the use of trade names?

Over-the-Counter Drugs

• Non-prescription drugs, also called over-the-counter drugs, are health products that can be bought without a doctor's prescription.
• Canada regulates non-prescription drugs to:
  • make sure they're safe to use
  • reduce health risks to Canadians
• Non-prescription drugs require a valid Drug Identification Number (DIN) to be sold in Canada. On a product label, this number indicates the drug has met our requirements for:
  • safety
  • quality
  • Effectiveness
• The label lists the drug's ingredients, so Canadians can avoid those that may cause concern.
• Canadian companies that manufacture, package, label and import non-prescription drugs must:
  • be licensed for these activities
  • provide the necessary documents and evidence

Pharmacokinetics

• The term pharmacokinetics is derived from two Greek words: pharmakon (drug or poison) and kinesis (motion)
• Pharmacokinetics is the study of drug movement throughout the body
• Pharmacokinetics also includes drug metabolism and drug excretion
• Application of pharmacokinetics in therapeutics
• Passage of drugs across membranes
  • Three ways to cross a cell membrane
  • Polar molecules
  • Ions

Absorption

• Movement of a drug from its site of administration into the blood
  • The rate of absorption determines how soon effects will begin
  • The amount of absorption helps determine how intense the effects will be
• Factors Affecting Drug Absorption
  • Rate of dissolution
  • Surface area
  • Blood flow
  • Lipid solubility
  • pH partitioning

Characteristics of Commonly Used Routes of Admistration

• Intravenous
  • Barriers to absorption
  • Absorption pattern
  • Advantages
  • Disadvantages
• Intramuscular
  • Barriers to absorption
  • Absorption pattern
  • Advantages
  • Disadvantages
• Subcutaneous
  • No significant barriers to absorption
• Oral
  • Barriers to absorption
  • Absorption pattern
  • Drug movement after absorption
  • Advantages
  • Disadvantages

ABSORTION P-Glycoprotein

• P-glycoprotein: Transmembrane protein that transports a wide variety of drugs out of cells
• Liver: Transports drugs into the bile for elimination
• Kidney: Pumps drugs into the urine for excretion
• Placenta: Transports drugs back into the maternal blood
• Brain: Pumps drugs into the blood to limit drugs’ access to the brain

Passage of Drugs Acorss Membranes

• For most drugs, movement throughout the body is dependent on the drug’s ability to penetrate membranes directly
• Most drugs are too large to pass through channels or pores
• Most drugs lack transport systems to help them cross all of the membranes that separate them from their sites of action, metabolism, and excretion
• A general rule in chemistry states that “like dissolves like”
• Cell membranes are composed primarily of lipids; therefore, to directly penetrate membranes, a drug must be lipid soluble (lipophilic)

Passage of Non-Lipophilic Molecules Acorss Membranes

• Polar molecules
  • Uneven distribution of a charge
  • No net charge
• Ions
  • Molecules that have a net electrical charge
  • Quaternary ammonium compounds
  • pH-dependent ionization
  • Ion trapping (pH partitioning)

Oral Administration and Absorption

• Tablets
• Enteric-coated preparations
• Sustained-release preparations