Midterm Outline

Chapter 1: The Role of the Advanced Practice Nurse as Prescriber

Roles and Responsibilities of APRN Prescribers

• Advanced practice: Engages in a high level of autonomy in clinical decision-making.
• Final decision for medications: Responsible for the choice and management of medication therapy.
• Degree of authority and autonomy decided state by state: Varies depending on state laws and regulations.
• Annual updates on titling, roles, and prescriptive authority: APRNs must stay informed of any changes.
• Scope of practice determined by NP license and licensing jurisdiction: Defined by legal and regulatory frameworks.
  • Employment sites may restrict this legal scope but cannot extend it: The scope of practice at a job may be more limited than the legal scope.

Clinical Judgement in Prescribing

• Clinical judgement: Involves assessing the best therapeutic approach considering multiple factors.
  • Best therapy should be least invasive, least expensive, least likely to cause abuse: Prioritize safety, efficacy, and cost-effectiveness.
  • Prefer lifestyle modifications, non-pharmacological, and pharmacological therapies: Consider all treatment options.
• Clear indication for drug therapy?
  • Before beginning, ask if necessary: Ensure there is a valid reason for starting medication.
• Effectiveness of drugs in treating the disorder
  • Choose the best one: Select medications based on efficacy and patient-specific factors.
• Goal of therapy with this drug
  • Cure disease, improve lifestyle, consider adverse effects: Define and monitor treatment objectives.
• Not meeting goals?
  • Consult a therapist when needed: Seek collaboration if treatment is not effective.
• Avoid unnecessary duplication with other drugs already taken: Prevent polypharmacy.
• Consider over-the-counter drugs: Evaluate the suitability of OTC options.
• Cost considerations
  • Will the patient pay out of pocket?: Assess the financial impact on the patient.
• Sources of information to answer questions
  • Journals, FDA, evaluate reliable drug information: Utilize credible sources for decision-making.

Collaboration with Other Providers

• Physicians, pharmacists, ARNPs, PAs, nurses: Engage in interdisciplinary collaboration to optimize patient care.

Autonomy and Prescriptive Authority

• Varies by state: Each state has different laws regarding the scope of practice and prescriptive authority of APRNs.

Chapter 2: Review of Basic Principles of Pharmacology

Metabolism and Half-Life

• Metabolism affects onset, duration of action, and toxicity of medications
  • Converts one chemical into another: Drug metabolism transforms active drugs into metabolites.
• First-pass metabolism
  • Major organ for drug metabolism (liver): Liver is the primary site for drug metabolism.
  • Contains high amounts of drug metabolism enzymes: Enzymes in the liver metabolize drugs.
  • First organ encountered by the drug once absorbed by the GI tract: Drugs pass through the liver after absorption.
  • Determines if it can be given orally: First-pass effect influences oral bioavailability.
• Rate of drug metabolism
  • Depends on drug blood levels, related to drug per hour: Influences pharmacokinetics.
  • First-order metabolism: time drug decreases by half
    • 50% at one half-life, 75% at two half-lives, 87.5% at three half-lives: Describes the drug elimination process.

Drug Responses

• Receptors: agonists and antagonists
  • Agonists: drugs that produce receptor stimulation and change what they bind to
  • Antagonists: occupy receptor without stimulating them, prevent agonists from occupying them
• Partial agonists: Produce a weaker, or less efficacious, response than an agonist.
• Inverse agonists: Bind to the same receptor as an agonist but induce a pharmacological response opposite to that of the agonist.

Pharmacokinetics: Absorption, Distribution, Protein Binding, Metabolism (including first-pass and Phase I and II)

• Absorption
  • Affected by weight, solubility, and other factors: Influences how a drug enters the bloodstream.
  • GI factors like food can change absorption: Presence of food can alter drug absorption rates.
• Distribution
  • Membrane permeability (e.g., blood-brain barrier): Determines which drugs can enter the CNS.
  • Plasma protein binding
    • If not bound, higher levels in blood and tissues: Only unbound drugs are active.
  • Storage
    • Lipophilic drugs accumulate in fats, calcium in teeth: Affects drug storage and release.
• Metabolism
  • Phase I (non-synthetic): drugs are oxidized or reduced to more polar forms
  • Phase II (synthetic): polar groups like glutathione are conjugated to the drug
  • Cytochrome P450 metabolism
    • Mixed function, catalyzes the metabolism of many drugs, delays metabolism or extends life of competing drugs: Plays a crucial role in drug interactions.

Excretion: Renal, Biliary, Other (e.g., for volatile drugs)

• Renal
  • Organic anion transport: HCTZ, furosemide, PCN G, salicylates: Mechanism for drug excretion through kidneys.
• Biliary excretion
  • Drugs excreted into bile and eliminated in feces: Alternative route of excretion.
• Other
  • Volatile drugs excreted through lungs: e.g., anesthetic gase