Pharmacology Reviewer for NCLEX-RN 2026 (Complete Guide)

Pharmacological and Parenteral Therapies is the second-largest category on the NCLEX-RN, comprising 13-19% of the entire exam. For Filipino nurses, this is often the most feared category because US drug names, classifications, and clinical applications differ from Philippine practice.

This reviewer covers every Pharmacology topic tested on the 2026 NCLEX-RN, focusing on the prototype drugs and concepts that appear most frequently.

Why Pharmacology Is Hard for Filipino Nurses

Three specific challenges make NCLEX Pharmacology difficult:

1. Generic versus brand names. The NCLEX uses generic names (acetaminophen, not Tylenol). Filipino nurses often learned drugs by brand names common in the Philippines (e.g., Biogesic for paracetamol, which is acetaminophen).

2. US-specific medications. Some medications widely used in the US are uncommon in the Philippines, while some Philippine medications are unfamiliar in the US.

3. Calculation under pressure. The NCLEX has an on-screen calculator, but timing is tight. Practice without a calculator first, then with one for the exam.

This guide addresses all three challenges.

How to Approach NCLEX Pharmacology

You cannot memorize every drug. Instead, master the prototype drug for each class and understand class-wide principles.

Strategy:

• Learn the drug class (what it does mechanistically)
• Learn the prototype (most representative drug in the class)
• Learn the side effects (usually class-wide)
• Learn the contraindications
• Learn the monitoring parameters
• Learn the patient education points

Once you understand one drug in a class, you can answer questions about any drug in that class.

High-Yield Drug Classifications

These are the drug classes most heavily tested on the NCLEX-RN. Master these first.

Cardiovascular Medications

Beta-Blockers (-olol suffix)

Prototype: Metoprolol (Lopressor)

Other examples: Atenolol, Propranolol, Carvedilol

Mechanism: Block beta receptors, reducing heart rate, blood pressure, and contractility.

Indications: Hypertension, MI, heart failure, dysrhythmias, anxiety (off-label).

Side effects to know:

• Bradycardia (hold if HR <60)
• Hypotension
• Bronchospasm (caution in asthma)
• Hypoglycemia masking (in diabetics)
• Fatigue, depression

Patient teaching:

• Do not stop abruptly (rebound hypertension/tachycardia)
• Check HR before each dose
• Report HR <60 to provider
• Rise slowly to prevent orthostatic hypotension

NCLEX trick: Hold metoprolol if HR is below 60 or systolic BP below 90. This is heavily tested.

ACE Inhibitors (-pril suffix)

Prototype: Lisinopril (Zestril, Prinivil)

Other examples: Enalapril, Captopril, Ramipril

Mechanism: Inhibit angiotensin-converting enzyme, causing vasodilation and reducing aldosterone.

Indications: Hypertension, heart failure, diabetic nephropathy, post-MI.

Side effects:

• Dry persistent cough (15-20% of patients)
• Hyperkalemia (monitor potassium)
• Angioedema (life-threatening - swelling of face/lips/tongue)
• First-dose hypotension
• Renal impairment (monitor creatinine)

Contraindications:

• Pregnancy (teratogenic)
• Bilateral renal artery stenosis
• History of angioedema

NCLEX trick: Sudden lip/tongue swelling = stop ACE inhibitor immediately, this is anaphylactic-like angioedema.

Angiotensin Receptor Blockers (ARBs, -sartan suffix)

Prototype: Losartan (Cozaar)

Other examples: Valsartan, Irbesartan

Mechanism: Block angiotensin II receptors.

Use: Alternative to ACE inhibitors (less cough, less angioedema). Same indications.

Side effects: Hyperkalemia, hypotension (cough less common).

Calcium Channel Blockers

Two types:

Dihydropyridines (-dipine suffix): Amlodipine, Nifedipine

• Mainly vasodilation
• Side effects: peripheral edema, headache, flushing

Non-dihydropyridines: Verapamil, Diltiazem

• Affect heart rate and contractility too
• Side effects: bradycardia, constipation (verapamil), heart block

Indications: Hypertension, angina, dysrhythmias (non-dihydropyridines).

Diuretics

Loop diuretics (-semide suffix): Furosemide (Lasix)

• Most potent
• Side effects: hypokalemia, ototoxicity (IV push too fast), dehydration
• Monitor: potassium, BUN, creatinine
• Patient teaching: increase potassium-rich foods

Thiazide diuretics: Hydrochlorothiazide (HCTZ)

• Less potent than loops
• Side effects: hypokalemia, hyperglycemia, hyperuricemia (gout)
• Ineffective in renal failure

Potassium-sparing diuretics: Spironolactone, Triamterene

• Weaker but preserve potassium
• Side effects: hyperkalemia, gynecomastia (spironolactone)
• Used with loops/thiazides to balance potassium

NCLEX trick: Furosemide IV must be pushed slowly (over 1-2 minutes) to prevent ototoxicity (tinnitus, hearing loss).

Antiarrhythmics

Amiodarone (Cordarone):

• Multiple uses for various dysrhythmias
• Side effects: pulmonary toxicity (most serious), thyroid dysfunction, blue-gray skin, corneal deposits
• Long half-life (months in tissues)

Digoxin:

• Used for heart failure and atrial fibrillation
• Narrow therapeutic range (0.5-2.0 ng/mL)
• Toxicity signs: nausea, visual changes (yellow halos), dysrhythmias, bradycardia
• Hold if HR <60
• Check potassium (hypokalemia increases toxicity risk)

Anticoagulants

Heparin (IV/SubQ):

• Monitor aPTT (therapeutic 1.5-2.5 × control)
• Antidote: protamine sulfate
• Watch for HIT (heparin-induced thrombocytopenia)

Warfarin (Coumadin, PO):

• Monitor INR (therapeutic 2.0-3.0 for most indications)
• Antidote: vitamin K (FFP for emergencies)
• Avoid foods high in vitamin K (consistent intake, not avoidance)
• Multiple drug interactions

Direct Oral Anticoagulants (DOACs):

• Rivaroxaban, Apixaban, Dabigatran
• No routine monitoring needed
• Specific reversal agents (idarucizumab for dabigatran)
• Cleaner than warfarin

Low Molecular Weight Heparin (LMWH): Enoxaparin (Lovenox)

• SubQ administration
• No routine monitoring
• Used for DVT prophylaxis and treatment

Diabetes Medications

Insulin (most heavily tested category)

Onset, Peak, Duration - MEMORIZE THIS:

|--------------|-------|------|----------|

Critical rules:

• Always check blood glucose before administering insulin. Hold if hypoglycemic.

• Insulin onset must match food intake. Give rapid-acting insulin right before meal. Give regular insulin 30 minutes before meal.

• Mixing insulins: Draw up regular (clear) FIRST, then NPH (cloudy). "Clear before cloudy."

• Storage: Unopened in refrigerator. Opened vial at room temperature for 28 days.

• Hypoglycemia treatment: 15g fast-acting carb (juice, glucose tabs), recheck in 15 minutes. If still <70, repeat.

NCLEX trick: A patient with BG of 65 mg/dL should NOT receive insulin. Treat hypoglycemia first.

Oral Diabetes Medications

Metformin (Glucophage):

• First-line for type 2 DM
• Does NOT cause hypoglycemia as monotherapy
• Side effect: GI upset, diarrhea
• Contraindicated: renal failure (creatinine >1.5), held 24-48 hrs before/after contrast (lactic acidosis risk)

Sulfonylureas: Glipizide, Glyburide

• CAN cause hypoglycemia
• Take with meals

SGLT2 inhibitors: Empagliflozin (Jardiance)

• Newer class, also benefits heart and kidneys
• Side effect: UTIs, dehydration, euglycemic DKA

GLP-1 agonists: Semaglutide (Ozempic), Liraglutide

• Injectable (some oral options)
• Weight loss benefit
• Side effects: nausea, pancreatitis risk

Respiratory Medications

Bronchodilators

Short-acting beta-2 agonists (SABA): Albuterol (rescue)

• Use for acute attacks
• Rapid onset (within minutes)
• Side effects: tachycardia, tremor

Long-acting beta-2 agonists (LABA): Salmeterol, Formoterol

• Maintenance (not rescue)
• Never use alone for asthma (combine with inhaled corticosteroid)

Anticholinergics: Ipratropium (Atrovent), Tiotropium (Spiriva)

• Used for COPD primarily
• Side effects: dry mouth

Inhaled Corticosteroids (ICS)

Examples: Fluticasone, Budesonide, Beclomethasone

• Daily controller medication
• Reduce airway inflammation
• Side effects: oral candidiasis (rinse mouth after use)
• NOT for acute attacks

Leukotriene Inhibitors

Montelukast (Singulair):

• Oral, taken in evening
• Used for asthma, allergic rhinitis
• Black box warning: neuropsychiatric effects (depression, suicidal thoughts)

CNS Medications

Antidepressants

SSRIs (-tine, -pram suffixes): Sertraline, Fluoxetine, Citalopram

• First-line for depression
• Take 4-6 weeks for full effect
• Side effects: sexual dysfunction, GI upset, weight changes
• Serotonin syndrome (life-threatening): fever, agitation, muscle rigidity
• Black box warning: increased suicidal ideation in young adults

SNRIs: Venlafaxine, Duloxetine

• Used for depression, anxiety, neuropathic pain
• Side effects similar to SSRIs plus hypertension

Tricyclics (TCAs): Amitriptyline, Nortriptyline

• Older, more side effects
• Side effects: anticholinergic (dry mouth, urinary retention), cardiac toxicity in overdose
• Used now mainly for neuropathic pain, not depression

MAOIs: Phenelzine, Tranylcypromine

• Rare use due to dietary restrictions
• Avoid tyramine (aged cheese, cured meats, fermented foods) - causes hypertensive crisis
• Drug interactions with many medications

Anxiolytics

Benzodiazepines (-zepam, -zolam suffixes): Lorazepam (Ativan), Alprazolam (Xanax), Diazepam (Valium)

• Risk: respiratory depression, dependence, falls in elderly
• Antidote: flumazenil
• Used for acute anxiety, seizures, alcohol withdrawal

Buspirone (BuSpar):

• Non-addictive anxiolytic
• Takes 2-4 weeks for effect

Antipsychotics

First-generation (typical): Haloperidol (Haldol), Chlorpromazine

• Side effects: extrapyramidal symptoms (EPS - tremor, rigidity, akathisia), tardive dyskinesia, neuroleptic malignant syndrome (NMS)

Second-generation (atypical): Risperidone, Quetiapine, Olanzapine

• Less EPS but more metabolic side effects (weight gain, diabetes, lipid problems)
• Used for schizophrenia, bipolar disorder

Neuroleptic Malignant Syndrome (NMS):

• Life-threatening reaction to antipsychotics
• Signs: hyperthermia, muscle rigidity, altered mental status, autonomic instability
• Treatment: stop antipsychotic, dantrolene, supportive care

Mood Stabilizers

Lithium:

• Used for bipolar disorder
• Narrow therapeutic range (0.6-1.2 mEq/L)
• Toxicity signs: tremor (coarse), ataxia, confusion, seizures, dysrhythmias
• Maintain consistent sodium and fluid intake (low sodium increases lithium levels)
• Avoid NSAIDs (increase lithium levels)

Valproate (Depakote):

• Used for bipolar, seizures
• Side effects: weight gain, hair loss, hepatotoxicity, thrombocytopenia

Pain Medications

Non-opioids

Acetaminophen (Tylenol):

• Max 4g/day (lower in liver disease)
• Hepatotoxic in overdose
• Antidote: N-acetylcysteine (Mucomyst)

NSAIDs: Ibuprofen, Naproxen, Ketorolac

• Side effects: GI bleeding, renal impairment, cardiovascular risk
• Avoid in: peptic ulcer, renal disease, last trimester of pregnancy

Aspirin:

• Antiplatelet effect at low doses (81 mg)
• Reye's syndrome in children with viral illness (avoid)

Opioids

Examples: Morphine, Hydromorphone, Fentanyl, Oxycodone, Hydrocodone

Side effects to monitor:

• Respiratory depression (most concerning)
• Sedation
• Constipation (universal - start bowel regimen)
• Nausea
• Pruritus
• Urinary retention

Antidote: Naloxone (Narcan)

Key teaching:

• Take with food to reduce nausea
• Avoid alcohol
• Do not drive
• Constipation prevention essential (senna + docusate)

NCLEX trick: Respiratory rate <12 = hold opioid, may need naloxone.

Antibiotics

Penicillins (-cillin suffix)

Examples: Amoxicillin, Penicillin G, Piperacillin

• Cross-reactivity with cephalosporins (5-10%)
• Allergic reactions ranging from mild to anaphylaxis
• Take on empty stomach (some)

Cephalosporins (cef- prefix)

Generations 1-5 with increasing gram-negative coverage

Examples: Cefazolin, Ceftriaxone, Cefepime

• Use with caution in penicillin-allergic patients
• Disulfiram-like reaction with alcohol (some)

Macrolides (-mycin suffix)

Examples: Azithromycin, Erythromycin, Clarithromycin

• Alternative for penicillin allergy
• Side effects: GI upset, QT prolongation
• Drug interactions (CYP450 inhibitors)

Fluoroquinolones (-floxacin suffix)

Examples: Ciprofloxacin, Levofloxacin

• Black box warnings: tendinitis/tendon rupture, peripheral neuropathy, aortic aneurysm, CNS effects
• Avoid with dairy and antacids (decrease absorption)
• C. diff infection risk

Aminoglycosides

Examples: Gentamicin, Tobramycin, Amikacin

• Nephrotoxic and ototoxic
• Monitor peak and trough levels
• IV/IM only (not absorbed orally)

Vancomycin

• Used for MRSA, severe gram-positive infections
• Red Man Syndrome with rapid IV infusion (slow infusion over 60+ min)
• Monitor trough levels
• Nephrotoxic

Other High-Yield Medications

Corticosteroids (-sone suffix)

Examples: Prednisone, Methylprednisolone, Hydrocortisone, Dexamethasone

Short-term side effects:

• Increased appetite, weight gain
• Mood changes
• Hyperglycemia
• Insomnia

Long-term side effects:

• Osteoporosis
• Cushing's syndrome (moon face, buffalo hump)
• Cataracts, glaucoma
• Immunosuppression
• Adrenal suppression (taper slowly)
• Hypertension
• Hyperglycemia/diabetes

Patient teaching:

• Take with food
• Do not stop abruptly
• Monitor blood sugar
• Increased infection risk

Statins (-statin suffix)

Examples: Atorvastatin (Lipitor), Simvastatin, Rosuvastatin

Side effects:

• Muscle pain (myopathy)
• Rhabdomyolysis (severe, rare)
• Liver enzyme elevation

Patient teaching:

• Report unexplained muscle pain
• Avoid grapefruit juice (increases statin levels)
• Take at bedtime

Dosage Calculations

The NCLEX includes dosage calculation questions. Master these formulas.

Basic Formula

Dose Desired / Dose Available × Quantity = Amount to Give

Example: Order: Acetaminophen 650 mg PO. Available: 325 mg tablets.

(650 / 325) × 1 = 2 tablets

Weight-Based Calculations

Convert pounds to kilograms first: lbs ÷ 2.2 = kg

Example: Order: Medication 5 mg/kg. Client weighs 132 lbs.

132 ÷ 2.2 = 60 kg

60 × 5 = 300 mg

IV Drip Rate Calculations

(Volume in mL / Time in minutes) × Drop factor = gtt/min

Example: Infuse 1000 mL over 8 hours with drop factor 15 gtt/mL.

8 hr × 60 = 480 min

(1000 / 480) × 15 = 31.25 → 31 gtt/min

IV Pump Calculations

Volume / Hours = mL/hour

Example: Infuse 250 mL over 2 hours.

250 / 2 = 125 mL/hour

High-Alert Medications (Memorize These)

The Institute for Safe Medication Practices (ISMP) lists high-alert medications requiring double verification:

• Heparin and other anticoagulants
• Insulin
• Opioids (especially IV)
• Concentrated electrolytes (potassium chloride)
• Chemotherapy agents
• Neuromuscular blockers (paralytics)
• Magnesium sulfate

NCLEX trick: Any question about heparin, insulin, or potassium chloride likely requires double verification or specific safety practices.

Critical rule: Potassium chloride IV must NEVER be given as IV push - always diluted and infused slowly via pump. Rapid administration causes fatal cardiac arrest.

NCLEX Pharmacology Study Strategy

Week 1: Cardiovascular medications

Master beta-blockers, ACE inhibitors, ARBs, calcium channel blockers, diuretics, anticoagulants.

Week 2: Endocrine medications

Focus heavily on insulin (most tested), oral diabetes medications, corticosteroids, thyroid medications.

Week 3: CNS medications

Antidepressants, anxiolytics, antipsychotics, mood stabilizers, antiepileptics, pain medications.

Week 4: Other systems

Respiratory, GI, antibiotics, antineoplastics, immunosuppressants.

Daily practice: 30-50 pharmacology questions per day with full rationale review.

Memorize antidote pairs:

• Heparin → Protamine sulfate
• Warfarin → Vitamin K
• Opioids → Naloxone
• Benzodiazepines → Flumazenil
• Acetaminophen → N-acetylcysteine
• Iron → Deferoxamine
• Magnesium → Calcium gluconate

Practice NCLEX Pharmacology at LisensyaPrep

LisensyaPrep's NCLEX Quiz Module 1 contains 50 practice questions specifically on Pharmacology, covering drug classifications, dosage calculations, IV therapy, side effects, and high-alert medications.

Start Module 1: Pharmacology Practice

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