Many companies manufacture drugs of identical chemical composition to brand-name drugs. Many commonly prescribed drugs have generic therapeutic equivalents. Some prescription drugs are protected by patent, however, and therefore no generic substitute exists. Always ask your doctor if there is a generic therapeutic equivalent to your medication and whether he or she plans to use it. Your pharmacist chooses generic substitutes from this list of FDA-approved drugs.
Some generic drugs are readily available at pharmacies.
If a generic drug is unavailable because it is out of stock, the pharmacist must tell you so. That gives you the option of waiting for the generic drug to be restocked or filling your prescription elsewhere. B rand-name drugs carry a company's trademarked name. Brand names are usually shorter and easier to pronounce and remember than the corresponding generic names. For example Darvon, a pain killer, is the brand name for propoxyphene hydrochloride.