What You Need to Know About Generic Drugs

By Tod Cooperman, MD, President, ConsumerLab.com

Posted on | By Tod Cooperman, MD

More than 80% of the drugs we take in the US are now generic versions of brand name medications. You may think that these drugs are equivalent to their branded counterparts, but that’s not always the case. Here are some important facts and tips to stay safe with generic drugs.

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Fact: You may get more or less active drug from a generic.

The FDA only requires that you get 80% to 125% of the drug into your bloodstream from a generic medication compared to the original drug. What’s even more concerning is that there are often many different generic versions of the same drug, and each of these may be different as well. Consider this: If you take a generic which only meets the minimum requirement and refill that prescription with one that’s at the maximum limit, you’ve potentially increased the amount you get into your body by as much as 45% percentage points – and you would have no way of knowing this from the labels, but it could certainly affect you. The opposite could also happen, and you would be getting a lot less drug than you were previously – which could also affect you.

This is particularly troubling for medications for which blood levels must be kept in a narrow range in order to be effective and/or to avoid toxicity. These can include:

  • Thyroid medication
  • Anti-seizure medication
  • Blood thinners
  • Antidepressants
  • Antipsychotics
  • Asthma medications
  • Immunosuppressants 

Fact: Other than the active ingredient, a generic may contain very different other binders and fillers.

Most of the ingredients in a pill are not the active ingredient but other ingredients needed to hold the pill together, coat it, and control the way the pill delivers its drug in your body. These other ingredients can be different in a generic version of a drug. It is possible to have an allergic reaction or sensitivity to one of these ingredients. With some extended-release products, the brand name formula is still patented, so the generics may be completely different in their formulation. This can affect how fast or slow they release their drug and how this is affected by things like whether you take the pills with food or not.

Fact: Generics are not tested like brand name medication.

While brand name medication is tested for safety and efficacy before being approved, generics are not. The only human test in people that is required is a bioequivalence test, conducted by the manufacturer in a small number of healthy individuals. This test must show that the product delivers approximately the same amount of drug into your blood stream and approximately the same rate.

Fact: Labels on most generic drugs are incorrect.

The FDA requires that the package inserts for generic drugs show the data (the “pharmacokinetic” data) from the brand name medication as if it is were based on the performance of the generic drug. In actuality, the data for the generic is typically different, but the FDA does not release this information.

Fact: In 2012, the FDA conceded that several generic antidepressant medications had never been tested and one was pulled from the market.

These were generic versions of Wellbutrin XL 300. One of them, called Budeprion XL 300 (Teva), had been on the market since 2006. Four others remain on the market. ConsumerLab.com drew attention to problems with this group of drugs in 2007 when it showed the Teva product did not dissolve like the original drug and many people switched to the drug reported that it was not working and some reported becoming suicidal. (Access to ConsumerLab.com’s report is available through a 24-hour free pass to Dr. Oz viewers. Visit ConsumerLab.com/DoctorOz now and get immediate access.) 

 

Guidelines for Going Generic

 

Guideline 1: Consider brand names for extended-release generic drugs.

While the active ingredients may be identical, the pills and their other ingredients in extended-release medications may not be. This makes extended-release generics, which typically have XL, ER, or SR in their names, more susceptible to delivering lower or higher amounts of the drug into your blood stream and at faster or slower rates than the brand name medication. As noted, this has been an issue with generic Wellbutrin XL 300. Concerns have also been reported with generic versions of Toprol XL. ConsumerLab.com has published reports on these products.

 

Guideline 2: Identify the manufacturer for generic drugs.

Not all generics behave the same way. If your generic is working, you should request the same manufacturer each time you refill that prescription. You can find the name (sometimes an abbreviation) on the bottle. Don’t be shy. You can call around to try to find the same product. Pharmacists will tell you which version they are currently selling and may be able to get the version you want. 

 

Guideline 3: Find out if an “authorized” generic exists for your drug.

These are generics typically made by the same manufacturer of the brand name medication but sold under a generic brand name. They are not “similar” to the brand name drug – they are identical to it. They just have a different imprint on them. Ask your pharmacist if one exists for your medication.

Guideline 4: When switching to a generic, monitor your condition carefully.

When switching from a brand name to a generic drug, or from one generic to another, note any changes you feel and tell your doctor immediately. It could be a difference in the medication causing the changes in you.

If you have experienced an unexpected and adverse change in your condition after being switched to a generic medication, you or your doctor may also want to report this to the FDA though its MedWatch program. You can also report this to ConsumerLab.com, which may choose to investigate the issue.

Article written by Tod Cooperman, MD
President, ConsumerLab.com