Pharmacy technicians frequently ask patients when filling a prescription if generic medications are OK to be substituted for brand-name drugs. But for patients to know how to answer this question, they must understand the differences between the two.
The U.S. Food and Drug Admini- stration (FDA) defines a generic drug as a “medication created to be the same as an already marketed brand-name drug in dosage form, safety, strength, route of administration, quality performance characteristics and intended use.1 This means generic medications must have the same active ingredients as the brand-name medications and work in the same manner. Generic drugs may only differ in the inactive ingredients such as filler agents, flavoring and/or coloring. And, all generic drugs are required to meet the same safety standards as brand-name medications, as well as adhere to FDA manufacturing standards.
Why Are Generic Drugs Important?
Today, generic drugs cost much less than brand-name drugs. For instance, in 2021, the United States spent $603 billion for the 8.743 million prescriptions dispensed. Of those, only 20 percent were for brand-name medications, but they accounted for 80 percent of healthcare dollars spent on prescription drugs.2
There are instances in which the use of generic medications should be reviewed by a prescriber, pharmacist and patient prior to using.
Prior to the mid-1980s, generic drug manufacturers were required to perform the same extensive testing when developing drugs as is required for branded drugs. Unfortunately, this provided little incentive for generic drug manufacturers to bring generics to market because the testing costs substantially raised the drugs’ price. As such, the Drug Price Competition and Patent Term Restoration Act of 1984, more commonly known as the Hatch-Waxman Act, was passed to allow generic drug manufacturers to forgo the extensive clinical testing required to bring new medications to market to make them lower in cost than brand-name medications. In return, drug manufacturers were granted a 20-year patent on brand- name drugs from the dates the patents are filed.
On average, a new drug takes 10 years to develop at an estimated cost of $2.6 billion.3 This means that most brand-name medications have approximately 10 years before generic drugs can compete with the brand-name drug unless FDA grants it an exclusivity, which is a specific delay and prohibition on any competitor drugs. Patents and exclusivity may be concurrent or consecutive, depending on the type of exclusivity granted (Table). This helps to “promote a balance between drug innovation and greater public access to drugs that result from generic drug competition.”4
Table. Types of FDA Exclusivity
| Exclusivity | Exclusivity Length | Reason |
|---|---|---|
| New chemical entity | 5 years | Brand-name drug with a new active moiety |
| New clinical investigation | 3 years | Brand-name drug that has a different disease or condition that can be treated or a new way of delivering the active ingredient (e.g., a tablet instead of a liquid); new human clinical studies are required |
| Orphan drug exclusivity | 7 years | Brand-name drug for a disease or condition that affects fewer than 200,000 people or that affects greater than 200,000 people but the drug company has little chance of recovering development costs |
| Pediatric | 6 months | When pediatric studies are conducted due to a written request by FDA |
| Antibiotics | 5 years | Certain antibiotics for specific infections and diseases |
Is There a Generic Drug Available?
To determine whether a generic is available for a brand-name medication, patients are encouraged to either ask their pharmacist or consult with reliable online resources.
Pharmacists are the best resource for available generics, as well as any possible concerns posed by those generic medicines. Reliable online resources that may be consulted include:
- Drugs@FDA: FDA-Approved Drugs, which is a catalog of FDA- approved drug products, including their drug labeling.
- FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book).
Should Generic Drugs Be Used with Caution?
There are instances in which the use of generic medications should be reviewed by a prescriber, pharmacist and patient prior to using. This is because there is a small (3.5 percent) difference in absorption between brand- name and generic medications. This difference is expected and is usually considered clinically insignificant since these differences are seen not only when comparing brand-name drugs versus generics, but between different generic manufacturers and different lots of brand-name drugs.1
There are also medicines that are considered narrow therapeutic index (NTI) drugs, which means there is only a small window between effective and toxic doses of them. FDA has categorized warfarin, levothyroxine, carbamazepine, digoxin, lithium carbonate, phenytoin and theophylline as NTI drugs. Cyclosporine, tacrolimus, sirolimus (immunosuppressants used in organ transplants) and antiepileptic drugs are also frequently considered NTIs even though they are not classified as such by FDA. And, due to the possible differences that may exist in the bioavailability of these drugs, any change from branded to generic should be discussed prior to switching.
Safe and Cost-Effective
In conclusion, generic medications are safe and cost-effective alternatives to brand-name medications for most patients. They must meet rigorous FDA approval and manufacturing standards to ensure they are equivalent. And, they are 80 to 85 percent less expensive, allowing for healthcare dollars to be maximized. When asked if it’s OK to substitute generic medications for brand-name medications, patients should ask questions and raise concerns with their pharmacists before confidently answering “yes.”
References
- U.S. Food and Drug Administration. Generic Drugs. Accessed at www.fda.gov/drugs/frequently-asked-questions-popular-topics/generic-drugs-questions-answers.
- Trends in Prescription Drug Spending, 2016-2021. Assistant Secretary for Planning and Evaluation Issue Brief, September 2022. Accessed at aspe.hhs.gov/sites/default/files/documents/88c547c976e915fc31fe2c6903ac0bc9/sdp-trends-prescription-drug-spending.pdf.
- Pharmaceutical Researchers and Manufacturers of America. Biopharmaceutical Research & Development: The Process Behind New Medicines. Accessed at phrma-docs.phrma.org/sites/default/files/pdf/rd_brochure_022307.pdf.
- U.S. Food and Drug Administration. Developing New Drugs. Accessed at www.fda.gov/drugs/development-approval-process-drugs.
