What is a drug suffix or stem?

A drug stem is a shared ending built into generic names by international naming conventions (USAN/WHO). Drugs in the same class are given the same stem, so the ending — like -statin or -pril — reliably signals what kind of drug it is.

Why do drugs in the same class share an ending?

Naming bodies assign a common stem to each class so clinicians and pharmacists can recognize a drug's family from its name alone. That's exactly why learning the stems is such a shortcut for memorization.

Do all drugs follow suffix patterns?

No. Many common drugs (like metformin or gabapentin) don't share a class stem, so you'll still need to learn those individually. But the patterns cover enough of the top drugs to dramatically cut your study load.

Drug suffixes & stems cheat sheet

Generic drug names aren't random. Drugs in the same class share a built-in ending — a stem — so once you learn the pattern, an unfamiliar name tells you its class on sight. This is the single biggest shortcut for memorizing the top 200 drugs.

-statinStatins

Lower LDL ('bad') cholesterol.

Examples: atorvastatin, rosuvastatin, simvastatin, pravastatin

-prilACE inhibitors

Lower blood pressure by blocking the ACE enzyme.

Examples: lisinopril, ramipril, enalapril, benazepril

-sartanARBs (angiotensin receptor blockers)

Lower blood pressure; often an alternative to ACE inhibitors.

Examples: losartan, valsartan, olmesartan, telmisartan

-ololBeta blockers

Slow heart rate and lower blood pressure.

Examples: metoprolol, atenolol, propranolol, nebivolol

-dipineCalcium channel blockers (dihydropyridines)

Relax blood vessels to lower blood pressure.

Examples: amlodipine, nifedipine

-prazoleProton pump inhibitors (PPIs)

Reduce stomach acid for reflux and ulcers.

Examples: omeprazole, pantoprazole, esomeprazole, lansoprazole

-tidineH2 blockers

Reduce stomach acid (a different mechanism than PPIs).

Examples: famotidine, cimetidine, nizatidine

-azepam / -zolamBenzodiazepines

Used for anxiety, seizures, and sleep.

Examples: clonazepam, lorazepam, temazepam, diazepam

-cillinPenicillin antibiotics

Treat bacterial infections.

Examples: amoxicillin, ampicillin, dicloxacillin

-cyclineTetracycline antibiotics

Broad-spectrum antibiotics for many infections.

Examples: doxycycline, minocycline

-floxacinFluoroquinolone antibiotics

Broad-spectrum antibiotics with a distinct safety profile.

Examples: ciprofloxacin, levofloxacin, ofloxacin, gatifloxacin

-mycinMacrolide (and related) antibiotics

Treat respiratory and other infections.

Examples: azithromycin, clarithromycin, clindamycin, tobramycin

-gliptinDPP-4 inhibitors

Oral type 2 diabetes medications.

Examples: sitagliptin, linagliptin, empagliflozin / linagliptin, alogliptin

-gliflozinSGLT2 inhibitors

Type 2 diabetes drugs that work through the kidneys.

Examples: empagliflozin, dapagliflozin, canagliflozin

-triptanTriptans

Treat acute migraine attacks.

Examples: sumatriptan, rizatriptan, naratriptan, zolmitriptan

-profenNSAIDs (propionic acid type)

Reduce pain and inflammation.

Examples: ibuprofen, flurbiprofen

Drill the suffix patterns

Learn My Drugs groups drugs by class so the shared endings click into place. Free to start, with spaced-repetition built in.

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Frequently asked questions

What is a drug suffix or stem?: A drug stem is a shared ending built into generic names by international naming conventions (USAN/WHO). Drugs in the same class are given the same stem, so the ending — like -statin or -pril — reliably signals what kind of drug it is.
Why do drugs in the same class share an ending?: Naming bodies assign a common stem to each class so clinicians and pharmacists can recognize a drug's family from its name alone. That's exactly why learning the stems is such a shortcut for memorization.
Do all drugs follow suffix patterns?: No. Many common drugs (like metformin or gabapentin) don't share a class stem, so you'll still need to learn those individually. But the patterns cover enough of the top drugs to dramatically cut your study load.

Educational study aid — not medical advice. Learn My Drugs is a memorization tool for pharmacy students, technicians, and exam prep. Drug names and uses on this page are simplified for studying and are not a substitute for professional judgment. For clinical, dosing, or safety information, consult the official label and a licensed professional.

Authoritative references: DailyMed, MedlinePlus, and the U.S. FDA.

Last reviewed: May 30, 2026.