Generic Drug Safety and Cost

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In the United States, brand name medications are developed under patent protection. A drug company may spend years—decades, even—researching and testing before bringing a new drug to market. Leaving controversies over brand-name drugs' high costs aside, a manufacturer's initial price for a new medication includes all the development costs it incurred for the drug. Patents on brand name drugs generally last 20 years.​​

As the expiration date of the patent approaches, any drug manufacturer (including the one that produced the brand-name version) may apply for permission to produce a generic version of the medication. Companies making generic versions of medications do not have to:

  • Do the research that was needed to create the drug in the first place;
  • Put the drug through clinical trials; or
  • Set up marketing campaigns for the generic drug.

Eliminating these three factors from the cost of manufacturing the generic drug means that a generic can be sold at a far lower price than the brand-name version.

Requirements for Generics

According to the U.S. Food and Drug Administration (FDA), "To gain FDA approval, a generic drug must:

  • contain the same active ingredients as the innovator drug (inactive ingredients may vary)
  • be identical in strength, dosage form, and route of administration
  • have the same use indications
  • be bioequivalent
  • meet the same batch requirements for identity, strength, purity, and quality
  • be manufactured under the same strict standards of FDA's good manufacturing practice regulations required for innovator products"

For a drug to be bioequivalent to its brand name counterpart, it must deliver the same amount of the active ingredient(s) in the same amount of time as the original.

This does not mean that all characteristics of a generic medication are the same as the original brand name drug. A generic must not look like the original due to trademark protection. Also, inactive ingredients, flavors, fillers, and dyes may be different from the brand name medication.

Problems With Generic Drugs

Most of the time generic drugs are just as safe and effective as their brand-name counterparts, but problems can arise. The most common reason for difficulties with generic drugs is that the inactive ingredients or excipients are different. Epilepsy Newfoundland and Labrador, an information and advocacy organization, notes:

  • "The active ingredient that helps control your seizures is the same in both 'brand' and 'generic' names, but the substances that are used as fillers, dyes, or binders sometimes differ. This can occasionally make a difference in how quickly they are absorbed from your stomach or processed by your body."

Some people are allergic to some excipients. In addition, a person's body may have become accustomed to the entire mix of active and inactive ingredients in one manufacturer's drug, and changing the mixture—even if there is no allergy to a new ingredient—may cause a change in response to the medication.

Examples of problems with generics:

  • Kimberly's pharmacy changed from one generic manufacturer to another for one of her medications. For two weeks she experienced painful gas and diarrhea while her body adjusted to the new generic.
  • Marcia's pharmacy changed her prescription from Prozac to a generic version, fluoxetine. She broke out in a rash—apparently an allergic reaction to one of the excipients in the generic.


You should not assume that you will have a problem when changing from brand name to generic or from one generic version of a drug to another. However, there are several steps you can take to minimize the risk of problems with generic medications, including noting the manufacturer on a list of your medication and checking the list each time you get a refill to see if the manufacturer has changed.

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Article Sources
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  1. U.S. Food & Drug Administration. Frequently asked questions on patents and exclusivity. Updated February 5, 2020.

  2. U.S. Food & Drug Administration. Generic drugs: Questions and answers. Updated June 1, 2018.

  3. U.S. Food & Drug Administration. What are generic drugs? Updated August 24, 2017.

  4. Dunne S, Shannon B, Dunne C, Cullen W. A review of the differences and similarities between generic drugs and their originator counterparts, including economic benefits associated with usage of generic medicines, using Ireland as a case study. BMC Pharmacology and Toxicology. 2013;14:1. doi:10.1186/2050-6511-14-1

  5. Epilepsy Newfoundland and Labrador. Medication. Published 2001.

  6. National Health Services. Fluoxetine (including Prozac). Updated December 10, 2018.