HESI 225 RN Pharmacology Exam

HESI 225 RN Pharmacology Exam Study Notes

1. General Principles of Pharmacology

Pharmacokinetics: Pharmacokinetic analysis explores drug transportation patterns across three integral stages: absorption, distribution and metabolism and excretion.

Absorption: The absorption process depends on drug formulation together with the route of administration and key patient attributes including gastric pH and gastrointestinal motility.

Distribution: Tissue absorption of drugs depends on blood circulation together with the binding power of protein and the drug's lipophilic nature.

Metabolism: During drug elimination the body utilizes mainly the liver cytochrome P450 system which performs biotransformation functions while taking drugs by mouth results in initial metabolism that lowers oral drug availability.

Excretion: Renal systems control drug elimination through glomerular filtration and tubular secretion and reabsorption processes while tests of creatinine clearance together with GFR should evaluate patient kidney function.

• Pharmacodynamics:

Mechanism of Action: Interaction of drugs with receptors (agonists vs. antagonists).

Therapeutic Index: The therapeutic index represents drug dosages between safety limits and toxicity levels and narrow TI drugs including digoxin and lithium need regular attentio

Half-life: Time to half drug elimination determines patients' medication dosage schedule and frequency of treatment.

• Adverse Drug Reactions (ADRs):

Type A (Augmented): Dose-dependent and predictable (e.g., hypotension with antihypertensives).

Type B (Bizarre): Idiosyncratic or allergic reactions (e.g., anaphylaxis).

2. Drug Classifications and Prototypes

• Antibiotics:

Penicillins (e.g., amoxicillin): The antibiotic works against gram-positive bacteria however patients need to be monitored for allergic reactions.

Cephalosporins (e.g., ceftriaxone): Cross-sensitivity with penicillins; nephrotoxicity risk.

Aminoglycosides (e.g., gentamicin): Medical staff should monitor both peak and trough levels of drugs which present risks of nephrotoxicity and ototoxicity.

Fluoroquinolones (e.g., ciprofloxacin): Risk of tendon rupture and QT prolongation.

• Cardiovascular Drugs:

Beta-blockers (e.g., metoprolol): The drug controls heart rate and blood pressure but doctors must be alert for signs of excessive slowing heartbeat or breathing troubles in people who have asthma.

ACE inhibitors (e.g., lisinopril): Heart failure and hypertension treatment capability exists in this medication but patients should expect both hyperkalemia and dry cough as potential side effects.

Calcium Channel Blockers (e.g., amlodipine): Vasodilation; monitor for peripheral edema.

Diuretics (e.g., furosemide): High doses of this drug may cause potassium depletion leading to hypokalemia in addition to ototoxicity. Patients require close monitoring.

• Central Nervous System Drugs:

Benzodiazepines (e.g., lorazepam): Anxiolytic and sedative; risk of dependence and respiratory depression.

• Antidepressants:

SSRIs (e.g., fluoxetine): First-line for depression; risk of serotonin syndrome.

TCAs (e.g., amitriptyline): Anticholinergic effects; high overdose toxicity.

Antiepileptics (e.g., phenytoin): Warfarin and phenytoin require monitoring of drug levels together with evaluations for gingival hyperplasia because they exhibit tight treatment windows.

• Endocrine Drugs:

Insulin: Insulin treatments feature rapid-acting (e.g., lispro) combined with short-acting (regular insulin) and intermediate (NPH) and long-acting forms (e.g. glargine). Continued monitoring of hypoglycemic events is necessary.

Thyroid Hormones (e.g., levothyroxine): Take the medication on an empty stomach while checking for TSH measurements.

Corticosteroids (e.g., prednisone): Anti-inflammatory properties exist in these medications but they may lead to osteoporosis and hyperglycemia and adrenal suppression when used over extended periods.

• Pain Management:

Opioids (e.g., morphine): Monitor for respiratory depression, constipation, and dependency.

NSAIDs (e.g., ibuprofen): Risk of gastrointestinal bleeding and renal impairment.

• Acetaminophen: Hepatotoxicity at high doses; maximum daily dose of 3-4 grams.

3. Dosage Calculations

Basic Formula:

Example: The prescribed dosage of 500 mg is available as 250 mg tablets in one tablet's amount. Dose =  tablets.

IV Flow Rate:

• .
• For drops/min: .

Pediatric Dosage:

• Based on weight: .
• Critical drugs require validation through body surface area (BSA) methodology for dosing calculation.

4. Special Populations

Pediatrics: The immature liver and kidney function of the patient should receive either weight-based or body surface area dosage calculations.

Elderly: Initiate treatment with small doses because patient clearance capacity is often diminished in cases of liver or kidney dysfunction.

Pregnancy and Lactation:

Patients should use FDA-designated drug classifications (A, B, C, D, X) while abstaining from use of teratogenic medications (including isotretinoin and warfarin).

Some drugs that pass through breastfeeding milk cause adverse effects on the baby's health.

5. Clinical Scenarios and Considerations

Medication Administration:

Follow the "6 Rights": In order to provide safe medication delivery services the practitioner must get everything correct from patient to medication to dosage to administration timing to proper documentation.

Verify medicine administration by using both patient identification methods including name and date of birth.

Monitor all medication delivery for possible errors then immediately report any detected pharmaceutical inaccuracies.

High-Alert Medications:

Examples: Insulin, anticoagulants (e.g., heparin, warfarin), chemotherapy agents.

Require double-checks and close monitoring.

Drug Interactions:

Additive effects (e.g., CNS depressants + alcohol).

Some drugs feature antagonistic effects which include naloxone interacting with opioids.

Food-drug interactions (e.g., grapefruit juice and statins).

Toxicity and Antidotes:

Acetaminophen: N-acetylcysteine.

Opioids: Naloxone.

Benzodiazepines: Flumazenil.

Warfarin: Vitamin K.

Heparin: Protamine sulfate.

Digoxin: Digibind (digoxin immune Fab).

6. Exam Tips

Prioritize Patient Safety:

The healthcare provider needs to detect potential scenarios where patients face increased safety risks during medication treatments including starting new prescriptions and caring for elderly persons with multiple medications.

Efforts should concentrate on quick identification of negative drug effects.

Use Critical Thinking:

Instructions for scenario analysis require evaluators to pose hypothetical questions (for example "What will occur if we miss the medication dose").

Integrate relationship between pharmaceutical science principles with clinical methods of care.

Time Management:

Allocate time evenly per question.

You should set aside time to revisit questions that prove challenging but if time is available.

WGU Fundamentals of Anatomy and Physiology D203 Exam

Nurs 255 B Adult Health 1

Enhanced Outline for The HESI 225 RN Pharmacology Exam Practice Questions

Topic: Application of Pharmacology in Clinical Decision-Making

Question: A 65-year-old male with a history of chronic hypertension, type 2 diabetes, and osteoarthritis presents to the emergency department with complaints of severe chest pain radiating to his left arm. The nurse conducts an assessment and observes the following findings:

Vital Signs:

• Blood pressure: 160/100 mmHg
• Heart rate: 110 bpm
• Respiratory rate: 18 breaths/min
• Oxygen saturation: 96%

Lab Results:

• Serum glucose: 150 mg/dL (elevated)
• Troponin: 1.5 ng/mL (elevated)
• B-type natriuretic peptide (BNP): 350 pg/mL (elevated)

Complaints:

• Severe chest pain, shortness of breath
• Nausea and lightheadedness

Which nursing intervention should be prioritized?

A) Administer aspirin and nitroglycerin to relieve pain and reduce blood clot formation.

B) Administer insulin to control blood glucose levels.

C) Administer a beta-blocker to reduce heart rate and myocardial oxygen demand.

D) Educate the patient on a low-fat diet to reduce the risk of future cardiovascular events.

Correct Answer: A) Administer aspirin and nitroglycerin to relieve pain and reduce blood clot formation.

Detailed Explanation:

The patient’s elevated troponin levels, elevated BNP, and symptoms of chest pain suggest an acute coronary syndrome (ACS), potentially a myocardial infarction (MI). The priority is to reduce the clot burden and relieve myocardial ischemia. Aspirin inhibits platelet aggregation, and nitroglycerin dilates coronary arteries, improving blood flow to the heart. These interventions are immediately critical for managing the patient’s acute chest pain and preventing further damage to the myocardium.

While managing blood glucose and providing education are important, addressing the acute cardiac issue is the priority to prevent further complications. The use of aspirin and nitroglycerin is well-supported by evidence-based guidelines in the management of ACS.

Why the Other Options Are Incorrect:

B) Administer insulin to control blood glucose levels? Although the patient’s blood glucose is elevated, the primary concern is the acute coronary event. Managing blood glucose is important in the long-term management of diabetes and heart disease but is not the immediate priority in an acute MI situation. Acute glucose control should follow stabilization of the patient’s cardiovascular status.

C) Administer a beta-blocker to reduce heart rate and myocardial oxygen demand? While beta-blockers are used in the management of acute coronary syndrome to reduce heart rate and myocardial oxygen demand, their administration is typically initiated after initial interventions such as aspirin and nitroglycerin. Beta-blockers should not be given if the patient is hypotensive, bradycardic, or in acute heart failure, as they could exacerbate these conditions.

D) Educate the patient on a low-fat diet to reduce the risk of future cardiovascular events? Although dietary education is crucial for long-term cardiovascular health, it is not a priority during an acute myocardial infarction. Immediate interventions should focus on relieving symptoms and stabilizing the patient, while long-term education can follow after the acute phase is managed.

Summary: Prioritizing pharmacological interventions based on the pathophysiology of the condition is essential in managing acute medical situations. For this patient, the focus must be on stabilizing the cardiovascular condition through the use of aspirin and nitroglycerin to address the acute coronary syndrome and prevent further myocardial injury. Other interventions such as glucose control and dietary education are important but secondary in the acute phase of care.

Topic: Application of Pharmacology in Clinical Decision-Making

Question: A 72-year-old female with a history of chronic atrial fibrillation and hypertension presents with complaints of dizziness, fatigue, and bruising. The nurse conducts an assessment and observes the following findings:

Vital Signs:

• Blood pressure: 128/75 mmHg
• Heart rate: 85 bpm (irregularly irregular)
• Respiratory rate: 16 breaths/min
• Oxygen saturation: 97%

Lab Results:

• Prothrombin time (PT): 22 seconds (elevated)
• International normalized ratio (INR): 4.2 (elevated)
• Hemoglobin: 11.0 g/dL (normal)

Complaints:

• Dizziness with positional changes
• Easy bruising

Which nursing intervention should be prioritized?

A) Administer vitamin K to reverse the anticoagulant effect and normalize the INR.

B) Administer the prescribed dose of warfarin as ordered.

C) Educate the patient about the importance of monitoring for signs of bleeding and the role of anticoagulation therapy.

D) Notify the healthcare provider and anticipate a change in the patient’s anticoagulant regimen.

Correct Answer: D) Notify the healthcare provider and anticipate a change in the patient’s anticoagulant regimen.

Detailed Explanation:

The patient’s elevated INR (4.2), along with dizziness and easy bruising, suggests that her anticoagulant therapy may be overcorrecting, increasing the risk of bleeding. Warfarin (Coumadin) is commonly prescribed to manage atrial fibrillation and prevent stroke, but an elevated INR indicates that the patient’s blood is too thin, and the risk for spontaneous bleeding is increased. The priority intervention is to notify the healthcare provider to assess the patient’s medication regimen and potentially adjust her warfarin dosage or switch to another anticoagulant to reduce the risk of bleeding.

While administering vitamin K could be considered to reverse the effects of warfarin, this should be done only under the guidance of the healthcare provider and in emergency situations, such as active bleeding. Immediate dose adjustments or changes in the anticoagulant therapy are more appropriate for managing this patient's current presentation.

Why the Other Options Are Incorrect:

A) Administer vitamin K to reverse the anticoagulant effect and normalize the INR? Vitamin K administration is used to reverse the anticoagulant effects of warfarin, but it is typically only required if there is active bleeding or if the INR is significantly elevated (usually above 5). In this scenario, adjusting the anticoagulant therapy rather than immediately administering vitamin K is the more appropriate course of action to avoid unnecessary intervention and bleeding risks.

B) Administer the prescribed dose of warfarin as ordered? The patient’s INR is elevated, suggesting that the prescribed dose of warfarin is too high and may result in an increased risk of bleeding. Continuing the same dose without adjusting the therapy could lead to more severe bleeding complications. The appropriate action is to notify the healthcare provider for an assessment and potential modification of the medication regimen.

C) Educate the patient about the importance of monitoring for signs of bleeding and the role of anticoagulation therapy? While patient education on the risks of anticoagulation therapy is important, this does not address the immediate concern of the patient’s elevated INR and potential bleeding risk. Prioritizing a change in the anticoagulant regimen will help manage the patient’s immediate safety, with education following after appropriate medical adjustments.

Summary: Managing anticoagulant therapy requires careful monitoring of INR levels to prevent complications like bleeding. In this case, the elevated INR suggests that the patient’s warfarin dosage needs to be adjusted. Prompt communication with the healthcare provider is critical to ensure the patient receives appropriate therapy to reduce the risk of hemorrhagic complications.

Key Notes for The HESI 225 RN Pharmacology Exam:

• Recognize Key Indicators: Understand the implications of laboratory results such as INR and PT in the context of anticoagulant therapy to identify overanticoagulation.

• Integrate Pharmacology Knowledge: Apply knowledge of anticoagulants like warfarin, including their therapeutic range and management of elevated INR levels, to make informed clinical decisions.

• Follow Evidence-Based Guidelines: Ensure interventions are in line with best practices for managing anticoagulation therapy, focusing on patient safety and bleeding prevention.

• Holistic Care: Collaborate with the healthcare team to adjust medication regimens, educate patients about their treatments, and ensure safe anticoagulant management.