The Complete NCLEX-RN Pharmacology Guide: Master Drug Classifications
Generic names carry WHO-assigned stems that announce the class. Learn ~two dozen suffixes and unfamiliar drugs decode themselves.
EH
Emily Hart, RN, BSN
Clinical Nurse Educator
6 min readUpdated Jul 2026
45+
Drug Classes Covered
120
Practice Questions
+23%
Pass Rate Improvement
The NCLEX uses generic drug names — and generic names are not random. Most carry a standardized stem, assigned under the WHO's International Nonproprietary Names system, that announces the drug's class. Learn perhaps two dozen stems and an unfamiliar medication stops being a guess: the name itself tells you the class, the class tells you the effects, and the effects tell you the nursing priority. That three-step decode is the highest-leverage pharmacology skill on the exam — because the test writers can always name a drug you've never studied, but they can't hide its suffix.
The decode: name → class → effects → priority
1
Read the suffix, name the class
"Never heard of alacepril" becomes "ends in -pril, so it's an ACE inhibitor" — and suddenly you have studied it. The WHO assigns these stems precisely so the name communicates the pharmacology.
2
Let the class supply the effects
Every ACE inhibitor shares the class signature: lowers blood pressure, spares potassium, and carries the famous dry cough plus the rare-but-lethal angioedema. Class effects are what the NCLEX actually tests — brand-specific trivia almost never appears.
3
Convert effects into the nursing priority
Potassium-sparing means you watch for hyperkalemia and question salt substitutes. The cough is expected teaching; facial swelling is stop-and-call. One suffix has now answered assessment, teaching, and escalation stems.
The cardiovascular stems — highest yield on the exam
Cardiovascular suffixes worth owning
Stem → class → the check the exam asks about
Comparison table of five cardiovascular drug suffixes: -pril ACE inhibitors watch potassium and cough, prototype lisinopril; -sartan ARBs same RAAS effects without the cough, prototype losartan; -olol beta blockers watch pulse and masked hypoglycemia, prototype metoprolol; -dipine calcium channel blockers watch blood pressure and edema, prototype amlodipine; -statin lipid agents watch for muscle pain, prototype atorvastatin
-pril
Stem
-pril
Class + prototype
ACE inhibitor — lisinopril
The exam's check
K+ up, dry cough expected, angioedema = stop
-sartan
Stem
-sartan
Class + prototype
ARB — losartan
The exam's check
Same RAAS story, no cough — the switch drug
-olol
Stem
-olol
Class + prototype
Beta-blocker — metoprolol
The exam's check
Pulse before dose; masks hypoglycemia; never stop abruptly
Stems per the WHO INN stem system; class effects are what the NCLEX tests.
Five suffixes cover the majority of cardiovascular medication stems.
Get free NCLEX-RN study tips
The highest-yield NCLEX-RN prep, in plain English, a few minutes a week.
By subscribing you agree to receive emails from HLT Mastery.
Weekly, never noisy
One short email a week — the highest-yield concept to review and a practice question to test yourself.
No spam, no sharing
Only prep that actually helps. Unsubscribe in one click, and we never share your email.
Beyond the heart: the stems that round out the exam
Seven more stems, seven more classes decoded
Comparison table of seven more drug suffixes: -prazole proton pump inhibitors, -tidine H2 blockers, -cillin penicillins, -floxacin fluoroquinolones, -vir antivirals, -zosin alpha blockers, and -azepam or -zolam benzodiazepines, each with prototype and key nursing watch
-prazole
Stem
-prazole
Class + prototype
PPI — omeprazole
The exam's check
Before meals; long-term fracture/B12 teaching
-tidine
Stem
-tidine
Class + prototype
H2 blocker — famotidine
The exam's check
The milder acid reducer; confusion in older adults
-cillin
Stem
-cillin
Class + prototype
Penicillin — amoxicillin
The exam's check
Allergy history FIRST; cross-reactivity questions
-floxacin
Stem
-floxacin
Class + prototype
Fluoroquinolone — ciprofloxacin
The exam's check
Tendon pain = stop and report; no antacids together
-vir
Stem
-vir
Class + prototype
Antiviral — acyclovir
The exam's check
Hydration (crystalluria); start early in outbreak
-zosin
Stem
-zosin
Class + prototype
Alpha-1 blocker — tamsulosin
The exam's check
First-dose orthostatic hypotension — rise slowly, dose at bedtime
Compare
Stem
Class + prototype
The exam's check
-prazole
-prazole
PPI — omeprazole
Before meals; long-term fracture/B12 teaching
-tidine
-tidine
H2 blocker — famotidine
The milder acid reducer; confusion in older adults
-cillin
-cillin
Penicillin — amoxicillin
Allergy history FIRST; cross-reactivity questions
-floxacin
-floxacin
Fluoroquinolone — ciprofloxacin
Tendon pain = stop and report; no antacids together
-vir
-vir
Antiviral — acyclovir
Hydration (crystalluria); start early in outbreak
-zosin
-zosin
Alpha-1 blocker — tamsulosin
First-dose orthostatic hypotension — rise slowly, dose at bedtime
Benzodiazepines carry two stems (-azepam, -zolam): sedation, falls, and reversal with flumazenil.
The GI, anti-infective, and neuro stems that fill most remaining medication items.
-pril vs. -sartan — same system, one famous difference. What's the sentence?
PRILs and SARTANs both quiet RAAS and both raise potassium — but only the PRIL makes you cough. The cough is bradykinin, the switch is to the SARTAN, and the emergency for both is angioedema.
Added to spaced-repetition deck
The decode gets you the class; the priorities still have to be second nature for the families the exam names outright — digoxin, insulin, the anticoagulant pair, potassium — covered with their checks and thresholds in the essential medications guide. And since medication knowledge is so often tested in select-all-that-apply form, the SATA strategy guide shows you the scoring math that decides how boldly to select.
