Generic names and brand names | Medications

Any FDA-approved drug has a generic name and a brand name. The United States Adopted Names (USAN) Council gives the generic name of a drug.

Generic name: The generic name consists of a stem and, sometimes, a substem that appears at the end of the name. Stems denote the chemical structure, indication, or action at a specific receptor. Drugs with the same stem are related. It also has a one or two-syllable prefix that differentiates each drug from others in its class.

For example, “sildenafil” and “tadalafil” have a stem “-afil” as they belong to the same class of medications called PDE5 (phosphodiesterase 5) inhibitors. The prefixes are “sil” and “tadal”. The “den” in sildenafil is known as an infix and may be used to classify certain medications further.

Brand name: A specific name given by a drug company or manufacturer protected by a patent.

For example, “Tylenol” is the brand name for “acetaminophen”.

Examples of brand names and generic names of common drugs

Brand name	Generic name
Protonix	Pantoprazole
Benadryl	Diphenhydramine
Tums	Calcium carbonate
Nasonex	Mometasone
Allegra	Fexofenadine
Ventolin	Albuterol

A generic medication may be sold under its generic or brand name. For example, Ibuprofen (generic) is sold under various brand names, such as Advil and Motrin.

Sidenote

Bioequivalence:

Generic versions of brand name drugs must be bioequivalent to the original drug. The two drugs should release the active ingredient into the bloodstream at the same amount, at the same rate, and have the same quality

Common drug name stems

Stem	Significance	Example
-stat	enzyme inhibitors	atorvastatin
-prazole	agents to treat ulcer and/or heartburn	omeprazole
-lukast	leukotriene receptor antagonists	montelukast
-grel	platelet aggregation inhibitors	clopidogrel
- faxine	antidepressant inhibitor of norepinephrine and dopamine reuptake	venlafaxine
-oxetine	antidepressants with a chemical structure related to fluoxetine	duloxetine
-sartan	angiotensin II receptor antagonists	valsartan
-oxacin	antibiotics that are chemical derivatives of quinolone	levofloxacin
-vir	antiviral compounds	valacyclovir
-mab	daclizumab	monoclonal antibodies
alol	Combined alpha and beta blockers	labetalol
olol	Beta–blockers (propranolol type)	atenolol
olone	Steroids (no prednisone derivatives)	minaxolone
cillin	Penicillins	ampicillin
ase	Enzymes	dornase alfa
caine	Local anesthetics	dibucaine
–conazole	Antifungals (miconazole type)	fluconazole

Prefix “Peg” means that a biologic substance, such as peptide, is pegylated. Infix -io- is added to suggest a high iodine content (e.g. amiodarone). When -fos- appears anywhere in a drug name, the element phosphorus is present (e.g. ifosfamide).

Sidenote

Therapeutic equivalence:

Therapeutic equivalence = Bioequivalence + Pharmaceutical equivalence*
Therapeutically equivalent drugs are expected to have the same clinical effect and safety profile and contain identical amounts of the identical active drug ingredient in the identical dosage form and route of administration.
Therapeutically equivalent drugs can be substituted for each other.
Therapeutically equivalent drugs can still differ in shape, color, flavor, inactive ingredients etc.

*Pharmaceutical equivalence means drugs with identical active ingredients in identical amounts, forms, and routes of administration.