Adult Nursing Care Unit 2 Review: Pathophysiology & Pharmacology in Nursing

Key Concepts and Terminology

• Pathophysiology studies the functional changes associated with disease processes and how the body responds to these changes
• Pharmacology is the study of drugs, their sources, chemical properties, therapeutic uses, and effects on the body
• Pharmacokinetics describes how the body processes a drug through absorption, distribution, metabolism, and excretion (ADME)
• Pharmacodynamics refers to the biochemical and physiological effects of drugs on the body and the mechanisms of drug action
• Adverse drug reactions (ADRs) are unintended, harmful reactions to medications that occur at normal therapeutic doses
  • Can range from mild side effects to severe allergic reactions (anaphylaxis)
• Drug interactions occur when the effects of one drug are altered by the presence of another drug, herbal supplement, food, or drink
• Polypharmacy is the concurrent use of multiple medications by a patient, which increases the risk of drug interactions and ADRs

Pathophysiology Fundamentals

• Pathophysiology builds upon the principles of normal anatomy and physiology to understand disease processes
• Diseases can be classified as congenital (present at birth) or acquired (developed after birth)
  • Congenital diseases are often genetic in origin (cystic fibrosis)
  • Acquired diseases may result from environmental factors, lifestyle choices, or infections (diabetes, HIV)
• Inflammation is a protective response to tissue injury or infection characterized by redness, swelling, heat, pain, and loss of function
• Neoplasia refers to the abnormal growth of cells, which can be benign (non-cancerous) or malignant (cancerous)
• Homeostasis is the maintenance of a stable internal environment, which is disrupted in disease states
• Compensatory mechanisms are physiological responses that attempt to restore homeostasis in the face of disease or injury
  • Examples include increased heart rate in response to blood loss and increased respiratory rate in response to hypoxia

Common Diseases and Disorders

• Cardiovascular diseases affect the heart and blood vessels and include hypertension, coronary artery disease, heart failure, and stroke
• Respiratory disorders impact the lungs and airways, such as asthma, chronic obstructive pulmonary disease (COPD), and pneumonia
• Endocrine disorders result from hormonal imbalances and include diabetes mellitus, thyroid disorders, and adrenal insufficiency
• Gastrointestinal diseases affect the digestive system, such as gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD), and liver cirrhosis
• Neurological disorders impact the brain, spinal cord, and nerves, including Alzheimer's disease, Parkinson's disease, and multiple sclerosis
• Musculoskeletal conditions affect the bones, joints, and muscles, such as osteoarthritis, rheumatoid arthritis, and osteoporosis
• Infectious diseases are caused by pathogens like bacteria, viruses, fungi, and parasites (influenza, HIV/AIDS, tuberculosis)
• Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body (lung, breast, colorectal)

Pharmacological Principles

• Pharmacotherapeutics is the use of drugs to treat, prevent, or diagnose diseases and disorders
• Drug administration routes include oral, parenteral (injection), topical, inhalation, and rectal
  • The route of administration affects the onset, duration, and intensity of drug action
• Bioavailability refers to the fraction of an administered drug that reaches the systemic circulation unchanged
• Half-life is the time required for the concentration of a drug in the body to decrease by half
• Therapeutic index is the ratio between the toxic dose and the therapeutic dose of a drug, indicating its safety margin
• Dose-response relationship describes how the intensity of a drug's effects changes with increasing doses
• Factors influencing drug response include age, gender, body weight, genetic variations, and comorbidities

Drug Classes and Mechanisms

• Analgesics are used to relieve pain and include opioids (morphine), NSAIDs (ibuprofen), and acetaminophen
• Antibiotics treat bacterial infections by inhibiting cell wall synthesis (penicillins), protein synthesis (aminoglycosides), or DNA replication (fluoroquinolones)
• Antihypertensives lower blood pressure through various mechanisms, such as diuretics, beta-blockers, ACE inhibitors, and calcium channel blockers
• Antidiabetic medications control blood glucose levels by increasing insulin secretion (sulfonylureas), improving insulin sensitivity (metformin), or reducing glucose absorption (alpha-glucosidase inhibitors)
• Bronchodilators relax airway smooth muscles to improve airflow in conditions like asthma and COPD (beta-2 agonists, anticholinergics)
• Antidepressants treat depression by modulating neurotransmitter levels, such as selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs)
• Anticoagulants prevent blood clot formation and include heparin, warfarin, and direct oral anticoagulants (DOACs)
• Proton pump inhibitors (PPIs) reduce gastric acid secretion to treat GERD and peptic ulcer disease

Nursing Assessments and Interventions

• Nursing assessments gather information about a patient's health status, including vital signs, physical examination, and patient history
• Medication reconciliation involves reviewing and documenting all medications a patient is taking to ensure accuracy and prevent drug interactions
• Nurses monitor patients for therapeutic responses and adverse effects of medications
  • Therapeutic drug monitoring (TDM) measures drug concentrations in the blood to optimize dosing and minimize toxicity
• Medication administration requires following the "6 rights": right patient, drug, dose, route, time, and documentation
• Nurses educate patients and caregivers about proper medication use, storage, and potential side effects
• Nursing interventions aim to manage symptoms, prevent complications, and promote patient comfort
  • Examples include wound care, pain management, and fall prevention
• Nurses collaborate with other healthcare professionals to develop and implement individualized care plans

Treatment Protocols and Care Plans

• Treatment protocols are evidence-based guidelines for managing specific diseases or conditions
  • Protocols standardize care and ensure consistent, high-quality treatment across healthcare settings
• Care plans are individualized, patient-centered plans that outline nursing diagnoses, goals, interventions, and evaluations
• Nursing diagnoses identify patient problems or potential risks that can be addressed through nursing interventions (impaired skin integrity, acute pain)
• Goals are measurable, achievable targets that guide patient care and evaluate progress (reduce pain score from 7 to 3 within 24 hours)
• Interventions are specific actions taken by nurses to achieve patient goals and improve outcomes (administer analgesics, reposition patient every 2 hours)
• Evaluation assesses the effectiveness of interventions and determines if goals have been met or need to be revised
• Multidisciplinary collaboration involves working with physicians, pharmacists, therapists, and other professionals to provide comprehensive patient care

Clinical Considerations and Patient Education

• Age-related changes in pharmacokinetics and pharmacodynamics require dose adjustments and careful monitoring in older adults
• Pregnancy and lactation necessitate cautious medication use to minimize risks to the fetus or infant
  • Teratogenic drugs (isotretinoin) can cause birth defects and should be avoided during pregnancy
• Renal and hepatic impairment alter drug metabolism and excretion, requiring dose modifications or alternative therapies
• Cultural competence involves understanding and respecting patients' cultural beliefs, values, and practices related to health and illness
• Health literacy assessment helps identify patients who may need additional support in understanding and managing their medications
• Patient education should be tailored to individual learning styles, language preferences, and health literacy levels
• Teach-back method asks patients to explain key information in their own words to ensure understanding
• Medication adherence strategies include simplifying regimens, using pill boxes, and setting reminders
  • Motivational interviewing techniques can help patients overcome barriers to adherence and make positive behavior changes