By North Essay Help Editorial Team ·
Drug Classes by Suffix: The Complete Table (With Examples and Exceptions)
Generic drug names are built from stems that signal the drug's class. The system is managed by the World Health Organization's International Nonproprietary Names (INN) programme and, in the US, the USAN Council. Learning 40 stems lets you guess the class of hundreds of drugs. It's not perfect, so the exceptions are listed too.
Cardiovascular
| Suffix | Class | How it works (short) | Examples |
|---|---|---|---|
| -olol | Beta blocker | Blocks beta-adrenergic receptors; lowers heart rate and BP | metoprolol, atenolol, propranolol |
| -alol | Alpha and beta blocker | Blocks both | labetalol, carvedilol (exception: ends -ilol) |
| -pril | ACE inhibitor | Blocks conversion of angiotensin I to II | ramipril, lisinopril, perindopril |
| -sartan | Angiotensin II receptor blocker (ARB) | Blocks angiotensin II receptors | losartan, candesartan, valsartan |
| -dipine | Calcium channel blocker (dihydropyridine) | Relaxes arterial smooth muscle | amlodipine, nifedipine |
| -statin | HMG-CoA reductase inhibitor | Lowers LDL cholesterol | atorvastatin, rosuvastatin |
| -xaban | Factor Xa inhibitor | Anticoagulant | apixaban, rivaroxaban, edoxaban |
| -gatran | Direct thrombin inhibitor | Anticoagulant | dabigatran |
| -parin | Heparin derivative | Anticoagulant | enoxaparin, dalteparin |
| -grel | Platelet inhibitor (P2Y12) | Antiplatelet | clopidogrel, prasugrel, ticagrelor (exception: ends -elor) |
| -azosin | Alpha-1 blocker | Relaxes vessels and prostate smooth muscle | doxazosin, terazosin, prazosin |
| -semide / -etanide | Loop diuretic | Blocks sodium reabsorption in loop of Henle | furosemide, bumetanide |
| -thiazide | Thiazide diuretic | Blocks sodium reabsorption in distal tubule | hydrochlorothiazide |
| -gliflozin | SGLT2 inhibitor | Increases glucose loss in urine | empagliflozin, dapagliflozin |
Endocrine and metabolic
| Suffix | Class | How it works | Examples |
|---|---|---|---|
| -gliptin | DPP-4 inhibitor | Increases incretin levels | sitagliptin, linagliptin |
| -glutide / -tide | GLP-1 receptor agonist | Increases insulin, slows gastric emptying | semaglutide, liraglutide, dulaglutide |
| -glitazone | Thiazolidinedione | Increases insulin sensitivity | pioglitazone |
| -formin | Biguanide | Reduces liver glucose output | metformin |
| -dronate | Bisphosphonate | Inhibits bone resorption | alendronate, risedronate |
| -sone / -olone | Corticosteroid | Anti-inflammatory | prednisone, dexamethasone, prednisolone |
Gastrointestinal
| Suffix | Class | How it works | Examples |
|---|---|---|---|
| -prazole | Proton pump inhibitor | Blocks gastric acid secretion | pantoprazole, omeprazole, esomeprazole |
| -tidine | H2 receptor antagonist | Reduces acid secretion | famotidine |
| -setron | 5-HT3 antagonist | Antiemetic | ondansetron, granisetron |
Central nervous system
| Suffix | Class | How it works | Examples |
|---|---|---|---|
| -azepam / -azolam | Benzodiazepine | Enhances GABA effect | lorazepam, diazepam, alprazolam, midazolam |
| -triptan | Serotonin 5-HT1B/1D agonist | Treats migraine | sumatriptan, rizatriptan |
| -oxetine / -aline | SSRI / SNRI (common, not universal) | Blocks serotonin (and noradrenaline) reuptake | fluoxetine, duloxetine, sertraline |
| -triptyline / -ipramine | Tricyclic antidepressant | Blocks reuptake; many receptor effects | amitriptyline, nortriptyline, imipramine |
| -apine / -idone | Atypical antipsychotic | Dopamine and serotonin receptor antagonism | olanzapine, quetiapine, risperidone |
| -caine | Local anesthetic | Blocks sodium channels in nerves | lidocaine, bupivacaine |
| -curium / -curonium | Neuromuscular blocker | Paralysis during anesthesia | rocuronium, cisatracurium |
| -barbital | Barbiturate | Enhances GABA (older drugs) | phenobarbital |
Anti-infectives
| Suffix | Class | Examples |
|---|---|---|
| -cillin | Penicillin | amoxicillin, piperacillin |
| cef- / ceph- (prefix) | Cephalosporin | cephalexin, ceftriaxone, cefazolin |
| -floxacin | Fluoroquinolone | ciprofloxacin, levofloxacin, moxifloxacin |
| -mycin | Antibiotic from Streptomyces (several classes) | azithromycin, clindamycin, vancomycin |
| -cycline | Tetracycline | doxycycline, minocycline |
| -penem | Carbapenem | meropenem, ertapenem |
| -conazole | Azole antifungal | fluconazole, voriconazole |
| -vir | Antiviral | acyclovir, oseltamivir, tenofovir |
Biologics and oncology
| Suffix | Class | Examples |
|---|---|---|
| -mab | Monoclonal antibody | adalimumab, pembrolizumab, trastuzumab |
| -cept | Receptor fusion protein | etanercept, abatacept |
| -tinib | Tyrosine kinase inhibitor | imatinib, osimertinib |
| -ciclib | CDK4/6 inhibitor | palbociclib, ribociclib |
For monoclonal antibodies, the letters before -mab used to show the source (-ximab chimeric, -zumab humanized, -umab human). The WHO revised this scheme in 2021, so newer antibodies use new stems such as -tug, -bart, -mig and -ment. Expect both systems on exams.
Exceptions that catch students
| Looks like | But is | Why it matters |
|---|---|---|
| -mycin is one class | Azithromycin (macrolide), clindamycin (lincosamide), vancomycin (glycopeptide) differ | Different spectra and side effects |
| -olol always cardioselective | Propranolol is non-selective | Asthma risk with non-selective beta blockers |
| -one always a corticosteroid | Spironolactone (diuretic) and methadone (opioid) also end in -one | Match the full stem: -sone or -olone |
| -tide always GLP-1 | Octreotide, leuprolide are different peptide drugs | -tide means peptide, not one class |
| -pine always a CCB | Olanzapine and quetiapine are antipsychotics (-apine) | Read the full stem: -dipine vs -apine |
| -vir all the same | Acyclovir (herpes), oseltamivir (influenza), tenofovir (HIV, hepatitis B) | Different viruses and mechanisms |
How to memorize them
- Learn by body system, not alphabetically.
- Pair each stem with one drug you'll see on placement (metoprolol, ramipril, pantoprazole).
- Build flashcards: suffix on the front, class + mechanism + one example on the back.
- Test with real medication lists from case studies.
Frequently asked questions
Who decides drug name suffixes?
The World Health Organization's INN programme sets international generic names. The USAN Council does this in the US, working with the WHO.
Do brand names follow suffix rules?
No. Only generic (nonproprietary) names use stems. Brand names are chosen by manufacturers.
What does -mab mean?
Monoclonal antibody. Newer antibodies named after the WHO's 2021 changes may use different stems.
What is the suffix for beta blockers?
-olol (metoprolol, atenolol). Combined alpha-beta blockers often end in -alol or -ilol (labetalol, carvedilol).
What's the difference between -pril and -sartan?
-pril drugs (ACE inhibitors) block angiotensin II production. -sartan drugs (ARBs) block its receptor. ARBs cause less dry cough.
Are drug suffixes the same in Canada and the US?
Yes for most drugs, as both use WHO-aligned generic names. A few names differ, such as salbutamol (Canada) vs albuterol (US). Both countries say acetaminophen, while most other countries say paracetamol.
Related guides and tools
- How to write a drug monograph assignment
- How to write nursing interventions
- Pharmacy assignment help
- Nursing assignment help
Sources: World Health Organization, The use of stems in the selection of International Nonproprietary Names (INN), and 2021 revision of the monoclonal antibody nomenclature scheme. USAN Council, stem list. This table is a study aid, not prescribing information.
