Healthcare Exams13 min read

NCLEX Pharmacology Guide 2026: Drug Classes, Calculations & Free Practice

Complete NCLEX pharmacology guide for 2026. Master drug classes, medication calculations, and nursing implications with free practice questions and AI tutoring.

Ran Chen, EA, CFP®January 12, 2026

Key Facts

  • Pharmacology accounts for 13-19% of NCLEX-RN questions
  • Learn drug classes by suffixes: -olol (beta blockers), -pril (ACE inhibitors)
  • The Six Rights are: patient, medication, dose, route, time, documentation
  • Heparin antidote is protamine sulfate; warfarin antidote is vitamin K
  • Naloxone (Narcan) reverses opioid overdose
  • High-alert medications include insulin, anticoagulants, and opioids

NCLEX Pharmacology Guide 2026: Master Medications for the NCLEX

Pharmacology accounts for 13-19% of the NCLEX-RN and is often considered the most challenging content area. This guide covers essential drug knowledge, calculations, and test strategies.

Pharmacology on the NCLEX

AspectDetails
Percentage13-19% of NCLEX-RN
Question TypesMultiple choice, SATA, calculations
Focus AreasDrug classes, side effects, nursing implications
Key SkillsSafe administration, patient teaching, calculations

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Essential Drug Classes for NCLEX

Cardiovascular Medications

Beta Blockers (-olol)

Examples: metoprolol, atenolol, propranolol

  • Action: Decrease heart rate and blood pressure
  • Uses: Hypertension, heart failure, angina
  • Side Effects: Bradycardia, hypotension, fatigue
  • Nursing: Check HR before giving (hold if <60), don't stop abruptly

ACE Inhibitors (-pril)

Examples: lisinopril, enalapril, captopril

  • Action: Block angiotensin-converting enzyme
  • Uses: Hypertension, heart failure, diabetic nephropathy
  • Side Effects: Dry cough, hyperkalemia, angioedema
  • Nursing: Monitor potassium, watch for cough, first-dose hypotension

Calcium Channel Blockers (-dipine)

Examples: amlodipine, nifedipine, diltiazem

  • Action: Block calcium channels, vasodilation
  • Uses: Hypertension, angina, arrhythmias
  • Side Effects: Peripheral edema, constipation, headache
  • Nursing: Monitor BP, check for edema, avoid grapefruit juice

Diuretics

TypeExamplesKey Point
Loopfurosemide, bumetanidePotassium wasting
ThiazideHCTZ, chlorthalidonePotassium wasting
Potassium-sparingspironolactoneRetain potassium

Anticoagulants and Antiplatelets

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Heparin

  • Route: IV or SubQ
  • Monitoring: aPTT (1.5-2.5x normal)
  • Antidote: Protamine sulfate
  • Nursing: No IM injections, watch for bleeding

Warfarin (Coumadin)

  • Route: Oral
  • Monitoring: PT/INR (goal usually 2-3)
  • Antidote: Vitamin K
  • Nursing: Consistent vitamin K intake, many drug interactions

DOACs (Direct Oral Anticoagulants)

Examples: rivaroxaban, apixaban, dabigatran

  • Advantage: No routine monitoring
  • Nursing: Assess for bleeding, limited reversal options

Diabetes Medications

Insulin Types

TypeOnsetPeakDuration
Rapid (lispro, aspart)15 min1-2 hr3-5 hr
Short (regular)30-60 min2-4 hr5-8 hr
Intermediate (NPH)1-2 hr4-12 hr18-24 hr
Long (glargine, detemir)1-2 hrNo peak24 hr

Key Nursing Points:

  • Check blood glucose before giving
  • Know signs of hypoglycemia
  • Rotate injection sites
  • Never shake insulin (roll NPH)

Oral Antidiabetics

  • Metformin - First-line, hold before contrast
  • Sulfonylureas (-ide) - Cause hypoglycemia
  • SGLT2 inhibitors (-flozin) - UTI risk

Pain Medications

Opioids

Examples: morphine, hydrocodone, oxycodone, fentanyl

  • Side Effects: Respiratory depression, constipation, sedation
  • Antidote: Naloxone (Narcan)
  • Nursing: Assess pain and respiratory status, prevent constipation

NSAIDs

Examples: ibuprofen, naproxen, ketorolac

  • Risks: GI bleeding, renal impairment
  • Nursing: Take with food, avoid in renal disease

Antibiotics

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ClassExamplesKey Points
Penicillinsamoxicillin, ampicillinAllergy risk, take on empty stomach
Cephalosporinscephalexin, ceftriaxoneCross-reactivity with PCN allergy
Fluoroquinolonesciprofloxacin, levofloxacinTendon rupture risk, avoid antacids
Aminoglycosidesgentamicin, tobramycinNephrotoxic, ototoxic, monitor levels
Macrolidesazithromycin, erythromycinGI upset, QT prolongation

Psychiatric Medications

Antidepressants

  • SSRIs (fluoxetine, sertraline) - 4-6 weeks for effect, serotonin syndrome risk
  • SNRIs (venlafaxine, duloxetine) - Monitor BP
  • TCAs (amitriptyline) - Anticholinergic effects, cardiac toxicity

Antipsychotics

  • Typical (haloperidol) - EPS, tardive dyskinesia
  • Atypical (risperidone, quetiapine) - Weight gain, metabolic syndrome

Mood Stabilizers

  • Lithium - Narrow therapeutic range, monitor levels, hydration critical

Medication Calculations

Dosage Calculations

Formula: Desired/Have × Quantity = Amount to give

Example: Order: 500mg. Available: 250mg tablets

  • 500mg/250mg × 1 tablet = 2 tablets

IV Flow Rates

Formula: (Volume × Drop factor) / Time in minutes = gtts/min

Example: 1000mL over 8 hours, drop factor 15

  • (1000 × 15) / 480 min = 31 gtts/min

Weight-Based Dosing

Formula: Weight (kg) × Dose per kg = Total dose

Example: Patient 70kg, order 2mg/kg

  • 70 × 2 = 140mg

Six Rights of Medication Administration

RightVerification
Right PatientTwo identifiers (name, DOB)
Right MedicationCheck label 3 times
Right DoseCalculate and verify
Right RouteAppropriate for medication
Right TimePer order and schedule
Right DocumentationAfter administration

High-Yield NCLEX Pharmacology Topics

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TopicFrequencyPriority
AnticoagulantsVery HighEssential
InsulinVery HighEssential
Cardiac medicationsHighImportant
AntibioticsHighImportant
Pain managementMediumReview
CalculationsMediumMust practice

Common Medication Errors to Know

Types Tested on NCLEX

  1. Wrong dose - Always calculate and verify
  2. Wrong patient - Use two identifiers
  3. Wrong route - Check order carefully
  4. Missed allergies - Always assess first
  5. Drug interactions - Know major interactions

Prevention Strategies

  • Follow the 6 rights
  • Use barcode scanning
  • Independent double-check for high-alert meds
  • Question unclear orders

Study Strategies for Pharmacology

1. Learn Drug Classes, Not Individual Drugs

Focus on:

  • Common suffixes (-olol, -pril, -statin)
  • Class actions and side effects
  • Nursing implications

2. Create Comparison Charts

Compare similar drugs:

  • Heparin vs warfarin
  • ACE inhibitors vs ARBs
  • Different insulin types

3. Focus on Safety

Know for each drug:

  • When to hold
  • What to monitor
  • Patient teaching points
  • Signs of toxicity

4. Practice Calculations Daily

  • Work through problems by hand
  • Check your work
  • Time yourself

Frequently Asked Questions

How much pharmacology is on the NCLEX?

Pharmacology accounts for 13-19% of NCLEX-RN questions. It's integrated throughout the exam, appearing in various clinical scenarios.

Should I memorize all drug names?

Focus on drug classes and their common characteristics. Knowing suffixes (-olol, -pril) helps identify drug classes quickly.

What calculations are on the NCLEX?

Basic dosage calculations, IV flow rates, and weight-based dosing. The NCLEX provides a calculator, but you must know how to set up problems.

What are high-alert medications?

Medications with high risk for harm if given incorrectly: insulin, anticoagulants, opioids, chemotherapy, potassium chloride.


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  • 500+ NCLEX-style questions
  • Drug class coverage
  • Calculation practice
  • Detailed rationales
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Test Your Knowledge
Question 1 of 4

Which medication class commonly ends in -olol?

A
ACE inhibitors
B
Beta blockers
C
Calcium channel blockers
D
ARBs
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