Generic vs. brand name medicines: Which is best?
Monday, April 22, 2013 10:00 PM
This week I want to tackle the subject of generic vs. name brand medications. There are a number of reasons this topic is important. First of all, medications in general are becoming prohibitively expensive for many patients. Insurance companies are also pressuring patients and physicians to prescribe generics whenever possible to reduce health care costs.
I receive many questions about generics in the office. People want to know why every medication doesn't have a generic substitute and if not, how long will it be until one is available. They also want to know if they are safe and effective.
First let me describe what generic and name brand drugs are. Generic drugs are chemical compounds that either never received patent protection or the patent on the name brand drug has expired. In contrast, name brand drugs are protected by a patent, meaning no other companies can produce or sell that particular drug.
This brings me to the answer for one of the most commonly asked questions - when will the generic version of a drug be available? When drugs are patented, the patent on that particular formulation is in effect for 20 years. The patents are granted shortly after the drug is discovered. This is usually long before it is even tested in clinical trials in humans, which can take between eight and 13 years. Therefore generics often aren't even available until seven to 12 years after the name brand hits the market.
Generic drugs are safe. To be approved by the FDA, a generic drug must be "bioequivalent" to the name brand product. This means that in studies comparing the generic to the name brand, that patients must absorb the same amount of the medication into the body and experience the same clinical effect. Here's the kicker - the generic has to be within a range of 80 to 125% of having the same bioequivalency. So, if your pharmacy buys a generic from Company A this month that's at 80 percent of the effectiveness of the name brand drug and next month buys from Company B that's at 125 percent, you could have a fairly wide swing of drug levels in your body.
For the vast majority of drugs this allowed variation does not result in any measurable clinical differences (i.e. the drugs are "safe"). However, most physicians feel that some generic drugs are not a prudent alternative (i.e. potentially "not safe"). These drugs typically are ones that require a very specific or narrow concentration in the body to either be effective or to not cause harmful toxicity or side effects. Frequently these drugs require patients to have blood drawn to monitor the levels of the drug in their bloodstream.
Medications used to treat seizures are the most common drug type where one needs to be careful with generics. If you absorb too little you may have a seizure. If you absorb too much you may have side effects like drowsiness. Likewise, the blood thinner Coumadin® (warfarin), also requires close monitoring to minimize the risk of bleeding or clotting. Many doctors don't recommend the use of generic warfarin, though if manufactured by the same company, it's less of an issue.
I sometimes hear, "the generic just doesn't work for me doc." This probably results from the natural variation among humans. Bioequivalency studies are based on the response of the "average" person to the drugs. That means there are folks out at the ends of the statistical bell curve that simply don't respond like the "average" person - some are more or less sensitive than the average person.
In summary, for the great majority of people and for most drugs, generics are a very safe and certainly less expensive alternative to name brands. It makes sense to discuss if a generic alternative is right for you with your physician.
Dr. John Roberts is a Crawfordsville physician and an owner of The Paper of Montgomery County. In addition to his weekly column, he publishes Health Tips on page A1 six days a week.