Pharmacology is 13-19% of the NCLEX-RN. You do not need every drug. You need classes, antidotes, and the side effects that hurt people.
Drug suffixes
| Suffix | Class | Example |
|---|---|---|
| -olol | Beta blocker | metoprolol |
| -pril | ACE inhibitor | lisinopril |
| -sartan | ARB | losartan |
| -dipine | Calcium channel blocker | amlodipine |
| -statin | Cholesterol lowering | atorvastatin |
| -prazole | Proton pump inhibitor | pantoprazole |
| -tidine | H2 blocker | famotidine |
| -parin | Heparin / LMWH | enoxaparin |
| -xaban | Factor Xa inhibitor | apixaban |
| -pam, -lam | Benzodiazepine | lorazepam, midazolam |
| -sone, -lone | Corticosteroid | prednisone |
| -cillin | Penicillin | amoxicillin |
| -floxacin | Fluoroquinolone | ciprofloxacin |
| -mycin, -micin | Aminoglycoside (gentamicin, tobramycin); not all -mycins (azithromycin is a macrolide) | gentamicin |
| -cycline | Tetracycline | doxycycline |
| -azole | Antifungal (except -prazole PPIs and metronidazole) | fluconazole |
| -vir | Antiviral | acyclovir |
| -triptan | Migraine | sumatriptan |
| -dronate | Bisphosphonate | alendronate |
Antidotes
| Opioids | Naloxone |
| Benzodiazepines | Flumazenil |
| Heparin | Protamine sulfate |
| Warfarin | Vitamin K (phytonadione) |
| Dabigatran | Idarucizumab |
| Acetaminophen | Acetylcysteine |
| Digoxin | Digoxin immune fab |
| Magnesium sulfate | Calcium gluconate |
| Insulin (hypoglycemia) | Dextrose or glucagon |
| Organophosphates | Atropine and pralidoxime |
Must-know side effects and teaching
- ACE inhibitors: dry cough; angioedema is an emergency; watch potassium.
- Beta blockers: check HR and BP; can mask hypoglycemia; caution with asthma.
- Digoxin: hold per parameters (often HR under 60); toxicity: nausea, vision changes; low K raises toxicity risk.
- Loop diuretics (furosemide): hypokalemia, dehydration, ototoxicity with rapid IV push.
- Potassium-sparing diuretics (spironolactone): hyperkalemia; avoid salt substitutes.
- Warfarin: keep vitamin K intake consistent; monitor INR; bleeding precautions.
- Heparin: monitor aPTT (or anti-Xa) and platelets (HIT).
- Statins: report muscle pain; liver function monitoring.
- Nitroglycerin SL: sit down; call 911 if chest pain is not better 5 minutes after the first dose; no PDE5 inhibitors (sildenafil).
- Insulin: know onset and peak; clear before cloudy; hypoglycemia signs.
- Metformin: held around IV contrast when kidney function is impaired (lactic acidosis).
- Levothyroxine: empty stomach in the morning; same time daily.
- Alendronate: empty stomach, first thing in the morning, full glass of plain water; stay upright with no food, drinks, or other meds for at least 30 minutes.
- Lithium: narrow therapeutic range; steady sodium and fluids; NSAIDs raise levels.
- MAOIs: avoid tyramine foods (aged cheese, cured meats) to prevent hypertensive crisis.
- SSRIs: watch for serotonin syndrome and increased suicidal thoughts early in treatment, especially in young people.
- Clozapine: agranulocytosis; report fever or sore throat.
- Aminoglycosides and vancomycin: kidney and ear toxicity; monitor levels.
- Isoniazid: liver toxicity; vitamin B6 prevents peripheral neuropathy.
- Rifampin: orange body fluids; reduces effectiveness of hormonal birth control.
- Phenytoin: gingival hyperplasia; good oral care.
High-alert medications
- Insulin, heparin and other anticoagulants, opioids, IV potassium, concentrated electrolytes, chemotherapy, neuromuscular blockers.
- IV potassium is never given IV push. Dilute and infuse at the rate allowed by policy.
Practice
A client taking digoxin has an apical pulse of 52/min and a serum potassium of 3.1 mEq/L. What should the nurse do?
Rationale: Bradycardia plus hypokalemia raises the risk of digoxin toxicity and dysrhythmias. Hold the dose and notify the provider. Hypokalemia increases digoxin's effect on the heart.
A client is receiving a continuous IV heparin infusion. Which laboratory value is most important for the nurse to monitor to titrate the infusion?
Rationale: Unfractionated heparin is titrated to the aPTT or anti-Xa level. PT/INR is used for warfarin. Also watch platelets for heparin-induced thrombocytopenia. The antidote is protamine sulfate.
A client taking warfarin has an INR of 6.2 and bleeding gums. Which medication should the nurse anticipate?
Rationale: Vitamin K reverses warfarin. Protamine reverses heparin, naloxone reverses opioids, and flumazenil reverses benzodiazepines.
The nurse is teaching a client who is starting lithium. Which statements should the nurse include? Select all that apply.
Rationale: Low sodium or dehydration raises lithium levels and causes toxicity, so intake should stay steady. GI loss and coarse tremor are signs of toxicity. NSAIDs raise lithium levels, and stopping abruptly risks relapse.
The nurse is teaching a client who is starting alendronate. Which instructions should the nurse include? Select all that apply.
Rationale: Alendronate is poorly absorbed with food or calcium and can cause esophageal irritation. Take it on an empty stomach with plain water and stay upright for 30 minutes.
Therapeutic drug levels: NCLEX lab values chart.
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Frequently asked questions
How much of the NCLEX is pharmacology?
Pharmacological and Parenteral Therapies makes up 13 to 19 percent of the NCLEX-RN, one of the largest categories.
What is the best way to study pharmacology for the NCLEX?
Learn drug classes by suffix, then learn the key side effects, nursing actions, and teaching for each class, plus the major antidotes and therapeutic levels.