Key Takeaways
- Every drug has three names: chemical name (scientific structure), generic name (nonproprietary), and brand name (manufacturer's trademark).
- Drug suffixes help identify drug classes: -olol (beta-blockers), -pril (ACE inhibitors), -statin (cholesterol-lowering), -prazole (proton pump inhibitors).
- Therapeutic classification groups drugs by what condition they treat; pharmacologic classification groups by mechanism of action.
- Generic drugs must be bioequivalent to brand-name drugs and contain the same active ingredient.
- The FDA Orange Book lists approved generic drug products with therapeutic equivalence ratings (A or B codes).
Drug Classifications and Naming Conventions
Quick Answer: Drugs have three names: chemical (scientific formula), generic (nonproprietary), and brand (trademarked). Drug suffixes help identify classes (e.g., -olol for beta-blockers). Generic drugs must be bioequivalent to brand names and are listed in the FDA Orange Book.
The Three Types of Drug Names
Every medication has three distinct names that identify it:
| Name Type | Description | Example (Atorvastatin) |
|---|---|---|
| Chemical Name | Scientific name describing molecular structure | (3R,5R)-7-[2-(4-fluorophenyl)-3-phenyl-4-(phenylcarbamoyl)-5-propan-2-ylpyrrol-1-yl]-3,5-dihydroxyheptanoic acid |
| Generic Name | Official nonproprietary name (lowercase) | atorvastatin |
| Brand Name | Manufacturer's trademarked name (capitalized) | Lipitor |
Key Point: Chemical names are rarely used in practice. Pharmacy technicians primarily work with generic and brand names.
Drug Suffixes (Stems) for Identification
Drug suffixes (or "stems") help identify which class a medication belongs to. This is critical for recognizing drug categories.
Common Drug Suffixes
| Suffix | Drug Class | Example Drugs |
|---|---|---|
| -olol | Beta-blockers | metoprolol, atenolol, propranolol |
| -pril | ACE inhibitors | lisinopril, enalapril, ramipril |
| -sartan | ARBs (Angiotensin II receptor blockers) | losartan, valsartan, irbesartan |
| -statin | HMG-CoA reductase inhibitors (statins) | atorvastatin, simvastatin, rosuvastatin |
| -prazole | Proton pump inhibitors (PPIs) | omeprazole, pantoprazole, esomeprazole |
| -tidine | H2 blockers | famotidine, ranitidine, cimetidine |
| -dipine | Calcium channel blockers (dihydropyridines) | amlodipine, nifedipine, felodipine |
| -azepam | Benzodiazepines | lorazepam, diazepam, clonazepam |
| -triptan | Migraine medications (serotonin agonists) | sumatriptan, rizatriptan, eletriptan |
| -cillin | Penicillin antibiotics | amoxicillin, ampicillin, penicillin |
| -mycin/-micin | Aminoglycoside antibiotics | gentamicin, tobramycin, amikacin |
| -floxacin | Fluoroquinolone antibiotics | ciprofloxacin, levofloxacin, moxifloxacin |
| -caine | Local anesthetics | lidocaine, bupivacaine, procaine |
| -zodone | Atypical antidepressants | trazodone, nefazodone |
| -oxetine | SSRIs | fluoxetine, paroxetine, duloxetine |
| -pine | Atypical antipsychotics | olanzapine, quetiapine, clozapine |
| -mab | Monoclonal antibodies | adalimumab, infliximab, rituximab |
| -vir | Antivirals | acyclovir, oseltamivir, tenofovir |
| -gliptin | DPP-4 inhibitors (diabetes) | sitagliptin, saxagliptin, linagliptin |
| -glutide | GLP-1 receptor agonists | semaglutide, liraglutide, dulaglutide |
Therapeutic vs. Pharmacologic Classification
| Classification Type | Based On | Example |
|---|---|---|
| Therapeutic | What the drug treats (condition) | Antihypertensive, Antidiabetic, Antidepressant |
| Pharmacologic | How the drug works (mechanism) | ACE inhibitor, SSRI, Beta-blocker |
Example: Lisinopril
- Therapeutic class: Antihypertensive (treats high blood pressure)
- Pharmacologic class: ACE inhibitor (blocks angiotensin-converting enzyme)
Generic vs. Brand Name Medications
Key Differences
| Aspect | Generic Drug | Brand Name Drug |
|---|---|---|
| Name | Official nonproprietary name (lowercase) | Trademarked name (capitalized) |
| Patent Status | Off-patent | Under patent protection initially |
| Cost | Generally 80-85% less expensive | Higher cost |
| Appearance | May differ (color, shape, size) | Unique appearance |
| Active Ingredient | Must be identical to brand | Original formulation |
| Inactive Ingredients | May differ | Unique formulation |
FDA Orange Book
The FDA Orange Book (Approved Drug Products with Therapeutic Equivalence Evaluations) lists:
| Rating | Meaning |
|---|---|
| A-rated | Therapeutically equivalent to reference product (can be substituted) |
| B-rated | NOT therapeutically equivalent (cannot be automatically substituted) |
Exam Tip: Know common drug suffixes and that A-rated generics are considered substitutable for brand-name drugs.
Narrow Therapeutic Index (NTI) Drugs
NTI drugs have a small difference between therapeutic and toxic doses. Generic substitution may be more closely regulated for these medications.
| NTI Drug | Use |
|---|---|
| Warfarin | Anticoagulant |
| Digoxin | Heart failure/atrial fibrillation |
| Phenytoin | Seizures |
| Lithium | Bipolar disorder |
| Levothyroxine | Thyroid replacement |
| Theophylline | Asthma/COPD |
| Carbamazepine | Seizures |
| Cyclosporine | Immunosuppression |
A medication with the suffix "-pril" belongs to which drug class?
Which of the following correctly describes the generic name of a drug?
According to the FDA Orange Book, which rating indicates that a generic drug can be substituted for the brand-name product?
Which of the following is considered a Narrow Therapeutic Index (NTI) drug requiring careful monitoring?