Naxlex NCLEX pharmacology review: high-yield drug classes and suffixes
Learn drug classes by suffix, key nursing actions and the safety checks NCLEX pharmacology questions test most.
Last reviewed October 21, 2026 · Naxlex RN Hub study team
NCLEX pharmacology questions test safe administration more than memorized doses. Learn drug classes by their suffixes, the one or two priority side effects of each class, and the check to make before giving it.
Suffixes group hundreds of drugs into a few classes. -olol is a beta blocker: check the apical pulse and blood pressure. -pril is an ACE inhibitor: watch for a dry cough, angioedema and high potassium. -statin lowers cholesterol: report muscle pain. -azole antifungals and many -mycin antibiotics have interaction and organ-toxicity concerns.
Some drugs have a narrow therapeutic range and keep reappearing: digoxin (about 0.5–2.0 ng/mL, depending on reference), lithium (about 0.6–1.2 mEq/L for maintenance), phenytoin, warfarin (INR goal usually 2–3) and vancomycin trough levels. Know the signs of toxicity and the antidote where one exists.
High-alert medications such as insulin, heparin, potassium chloride and opioids often need a second nurse to check. When a question offers 'hold and notify', ask whether the finding makes giving the drug unsafe.
Official reference resources
- NCLEX candidate tutorial and preparation resources
- Official computerized adaptive testing overview
- Official ATI TEAS information
FAQ
How much pharmacology is on the NCLEX-RN?
Pharmacological and Parenteral Therapies make up about 15% of the RN test plan, per NCSBN.
What is the antidote for heparin?
Protamine sulfate. For warfarin it is vitamin K, plus other reversal agents when urgent.
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