Generic medications are substitutes for brand name drugs. They're typically less expensive, widely available and commonly prescribed. According to the U.S. Food and Drug Administration (FDA), generics account for nearly 90 percent of all prescriptions filled in the United States. And, they can save consumers and hospitals significant amounts in health care costs.
In the treatment of Parkinson's disease (PD), one of the best-known generics is the immediate release form of carbidopa/levodopa, which substitutes for Sinemet. Recently, rasagiline -- the generic of Azilect (an MAO-B inhibitor) -- came on the market. With it, questions arose as to what generics really are, how they gain approval and what to consider when taking them.
Generics Are the Same as Brand Name Drugs
Generic drugs are essentially identical to their brand name counterparts. (More about this below.) They:
- are equal in strength (number of milligrams),
- come in the same dosage form (tablet or capsule, for example) and
- are administered via the same route (e.g., oral, inhaler, skin patch).
Generics are prescribed for the same reason as the brand name (i.e., to treat dyskinesia or ease motor symptoms). Modifications that don't impact the generic's efficacy or safety are allowed, so drugs may vary in shape, color, flavor or packaging.
FDA Is Responsible for Approving Generics
Companies that wish to make generic medications must submit an application to the FDA that includes data on the drug's effectiveness and safety. The active ingredient of the generic (the part that provides treatment) must be the same as that in the brand drug, and it must be absorbed by the body at the same rate and to the same extent. (Up to a 20 percent difference in a drug's absorption is acceptable.) The inactive components (anything other than the active ingredient) must be safe. To demonstrate these properties, clinical trials often are conducted in which volunteers take both brand name and generic formulations (at separate times). Generic manufacturers also supply information on exactly how and where drugs will be produced, and the FDA inspects facilities to ensure generic production will be consistent and reliable.
Generics Can Be Marketed When Patents Expire
Generics can't be marketed until a brand name drug's patent and other exclusivities expire. (That's why there may be a long lag time between generic drug approval and marketing.) These protections grant, among other things, the sole right to the brand name drug maker to sell the medication for a defined period of time so that they can recover some of the drug development costs. (Drug development takes up to a decade and a billion dollars because of the extensive clinical testing involved.) Patent and exclusivity periods may run concurrently but lengths vary depending on a number of factors; patents may last 20 years and exclusivities up to seven. Once these expire, generics can be marketed, typically at a much cheaper price than the brand name because they don't require lengthy and expensive clinical trials. As multiple generics for the same brand name come on the market, competition can drive costs down even further.
Considerations for Taking Generic Medications in Parkinson's
If generic medications are available, you may want to take them because of the financial savings. The best way to figure out if generics are an option is to ask your doctor and/or pharmacist. In some situations, your health insurance provider may require that you use the generic option. If, for some reason, you or your doctor prefer the brand name drug, this must be specified on your prescription and you may have a higher out-of-pocket payment. (Learn more about financial and other assistance programs for obtaining medications here.) If you do switch to generic from the brand name:
- monitor for new side effects, which may be the same as those for the brand name, but could potentially differ due to inactive ingredients in the generic, and
- pay attention to any changes in your PD. These would relate to the reason you're taking the medication. For example, if the medication is to ease Parkinson's motor symptoms and those seem worse, then perhaps the generic is not ideal for you.
Remember, though, that generics are required to be safe and just as effective as brand name drugs. So, it's unlikely that they would be less beneficial or cause significant problems. Still, some people don't respond as well to generics or have new side effects such that they need to take the brand name. As with any medication in your regimen, work with your physician to determine what best suits you and your situation.