Top Drug Categories Every Practical Nurse Must Know
Pharmacology is one of the most challenging—but also one of the most important—areas on the NCLEX-PN. It requires not just memorization, but deep understanding. You’re expected to know what a medication does, why it’s prescribed, how it should be administered, and most importantly, how to respond when something goes wrong.
The NCLEX-PN doesn’t ask you to regurgitate random drug facts. Instead, it tests your clinical judgment: Can you recognize a life-threatening side effect? Do you know which medication to ask? Are you aware of what teaching is necessary for patient safety?
To help you prepare with confidence, this blog will cover the top drug categories you MUST know, why they matter, and how to remember their key facts.
Why Pharmacology Matters on the NCLEX-PN
Nursing is more than giving medications—it’s about giving them safely. Adverse drug reactions, contraindications, and improper dosages can have serious consequences. That’s why 15% or more of the NCLEX-PN focuses on pharmacological therapies.
Here’s what the NCLEX is really testing when it comes to meds:
- Understanding indications, mechanisms, and therapeutic effects
- Recognizing serious side effects and adverse reactions
- Knowing essential patient teaching points
- Identifying drug interactions
- Monitoring lab values and vital signs related to meds
- Making safe and evidence-based nursing decisions
Let’s break down the essential drug categories every practical nurse needs to master before test day.
1. Antihypertensives
Why They Matter:
Hypertension is one of the most common chronic conditions you’ll encounter. These drugs reduce the risk of stroke, heart attack, and kidney damage.
Key Classes:
- ACE Inhibitors (e.g., lisinopril, enalapril)
- ARBs (e.g., losartan, valsartan)
- Beta-blockers (e.g., metoprolol, atenolol)
- Calcium Channel Blockers (e.g., amlodipine, diltiazem)
- Diuretics (e.g., furosemide, hydrochlorothiazide)
Must-Know Facts:
- ACE inhibitors can cause a dry cough and angioedema.
- Beta-blockers may mask signs of hypoglycemia.
- Furosemide can cause hypokalemia, ototoxicity, and hypotension.
Nursing Tips:
- Always check blood pressure and pulse before administering.
- Monitor electrolyte levels, especially potassium.
- Educate patients to rise slowly to avoid orthostatic hypotension.
2. Antibiotics
Why They Matter:
Infection control is fundamental in nursing care. Knowing your antibiotics can save lives—especially when identifying allergic reactions or superinfections.
Common Classes:
- Penicillins (e.g., amoxicillin)
- Cephalosporins (e.g., ceftriaxone)
- Macrolides (e.g., azithromycin)
- Fluoroquinolones (e.g., ciprofloxacin)
- Tetracyclines (e.g., doxycycline)
Must-Know Facts:
- Allergic reactions to penicillins may extend to cephalosporins.
- Tetracyclines cause photosensitivity and are not safe during pregnancy or for children under 8.
- Fluoroquinolones can cause tendon rupture.
Nursing Tips:
- Complete the full course of antibiotics.
- Monitor for signs of superinfection (e.g., oral thrush, diarrhea).
- Avoid giving tetracyclines with milk or antacids.
3. Insulins and Oral Antidiabetics
Why They Matter:
Managing diabetes requires precision. Both hyperglycemia and hypoglycemia can have life-threatening effects.
Types of Insulin:
- Rapid-acting: lispro (Humalog) – onset ~15 min
- Short-acting: regular insulin – onset ~30–60 min
- Intermediate-acting: NPH – onset ~1–2 hr
- Long-acting: glargine (Lantus) – no peak
Oral Medications:
- Metformin – decreases liver glucose production
- Glipizide – stimulates insulin secretion
Must-Know Facts:
- Metformin must be held 48 hours before/after contrast dye.
- Hypoglycemia is a major risk with insulin and sulfonylureas.
Nursing Tips:
- Know the onset, peak, and duration of each insulin type.
- Always check blood glucose levels before administering.
- Teach signs of hypoglycemia: shakiness, sweating, confusion.
4. Anticoagulants and Antiplatelets
Why They Matter:
These drugs prevent clots in patients with atrial fibrillation, DVT, PE, or after surgery. Mismanagement can lead to bleeding or clotting crises.
Common Meds:
- Warfarin (Coumadin) – Vitamin K antagonist
- Heparin – inhibits thrombin
- Enoxaparin (Lovenox) – low molecular weight heparin
- Aspirin, Clopidogrel – antiplatelets
Must-Know Facts:
- INR (2–3) monitors warfarin; PTT for heparin.
- Vitamin K reverses warfarin; protamine sulfate reverses heparin.
Nursing Tips:
- Monitor for signs of bleeding: bruising, tarry stools, hematuria.
- Teach patients to use soft toothbrushes and avoid NSAIDs.
- Be alert to interactions with antibiotics and herbal products (e.g., ginkgo).
5. CNS Drugs: Antipsychotics, Antidepressants, and Anticonvulsants
Why They Matter:
These medications affect mood, cognition, and neurological function—crucial in patients with mental illness, seizures, or chronic pain.
Key Types:
- SSRIs: fluoxetine, sertraline
- Benzodiazepines: lorazepam, diazepam
- Antipsychotics: haloperidol, risperidone
- Anticonvulsants: phenytoin, carbamazepine
Must-Know Facts:
- SSRIs risk serotonin syndrome: fever, agitation, tremors.
- Phenytoin causes gingival hyperplasia—oral hygiene is key.
- Benzodiazepines cause respiratory depression—especially with opioids.
Nursing Tips:
- Monitor mental status and suicidal ideation with antidepressants.
- Taper benzodiazepines to prevent withdrawal seizures.
- Educate on medication compliance, especially in seizure prevention.
6. Pain Management: Opioids and NSAIDs
Why They Matter:
Pain is the fifth vital sign, but overmedicating can lead to sedation, respiratory depression, or addiction.
Common Drugs:
- Opioids: morphine, hydromorphone, fentanyl
- NSAIDs: ibuprofen, naproxen, ketorolac
- Acetaminophen: Tylenol (non-NSAID)
Must-Know Facts:
- Opioids can cause respiratory depression, constipation, and urinary retention.
- Naloxone (Narcan) reverses opioid overdose.
- NSAIDs increase risk for GI bleeding and kidney injury.
Nursing Tips:
- Assess pain level, vitals, and sedation level before giving opioids.
- Monitor renal function with NSAIDs.
- Educate on non-pharmacological pain relief strategies as well.
Final Tips to Master Pharmacology for the NCLEX-PN
- Group drugs by class: Learn them in sets, not individually.
- Use flashcards: Prioritize side effects, nursing considerations, and interactions.
- Practice with NCLEX-style questions: Focus on application, not memorization.
- Know your antidotes: Like naloxone for opioids or protamine sulfate for heparin.
- Teach back: If you can explain it to someone else, you truly understand it.
In Summary
Pharmacology can feel like a mountain to climb, but knowing the core drug categories—and how they show up in real-life scenarios—gives you the edge you need to succeed on the NCLEX-PN. Focus on understanding rather than memorizing. Think like a nurse: What’s safest for the patient?
If you make medication safety a cornerstone of your NCLEX prep, you’re already thinking like a practical nurse.
