Generic Drug Side Effects May be Different

In a previous post Are Generic Medicines Just as Good?, I made the point that I thought in general, generic drugs are just a good as the brand name drug. I still believe this, however, the key phrase here is “in general.” I have seen a few medications that result in different side effects when patients took the generic drug. For example, Lamictal is known for possibly causing an allergic rash. Now that we increase the dose over six weeks, the incidence of the rash has significantly decreased. I have seen some patients develop the rash at low doses when they took the generic.

Similarly, a common side effect of Wellbutrin is increased activation or agitation. Many patients can take Wellbutrin without this unwanted side effect, but I’ve had some patients feel increased anxiety or agitation when they switched to generic Wellbutrin.

This is all antedoctal, that is, it’s not based on a head to head study of the generic medication versus the brand. Nevertheless, in my experience, it’s happened enough to take notice. Does this mean that the generic lamictal or generic Wellbutrin are not as good? No. It just means that the different generic manufacturers may have different inactive ingredients that can affect you differently. You don’t know what manufacturer you local pharmacy will use, and they may use a different company the next time you refill. The only way to insure consistency is to use the brand because you know what you will get each time.

For the many people who notice no difference when they take the generic drug, then by all means continue to save money by taking the generic drug. But for those who may be more sensitive to medication side effects, you may need your doctor to write “brand neccesary” on the prescription to avoid an unnecessary substitution to the generic drug.

Are Generic Medicines Just as Good?

I’ve always been a firm believer that brand didn’t matter much and you should save your money by passing up the $6 Advil for the $2 Ibuprofen. When I was in medical school and residency, we learned generic names for drugs so as not to give too much credit to the drug manufacturer and recognize the drug for it’s chemical properties (and not it’s brand name).

From time to time, I would hear of certain drugs that seem to be more effective than the generic version, however most of them were cardiac meds or non-psychiatric medications. Since the more popular antidepressants were developed in the 90′s, we (psychiatrists) didn’t have to think much about this issue because these drugs were still under patent until recently. Now some of the more popular antidepressants such as Prozac, Paxil, Zoloft and Wellbutrin are all off patent and available as generic.

What does this mean? (if you know about generics, you can skip this paragraph) Prozac is the brand name developed by Eli Lilly (the company who first developed and manufactured the drug). The chemical name is fluoxetine. Lilly paid for the development, research, and production of fluoxetine. To recoup their investment, they are allow protection for a certain number of years from any one else manufacturing fluoxetine. Once the patent expired, other drug manufacturers were allowed to produce fluoxetine and sell it. Now that’s there’s an open market for selling it, the price drops considerably.

Back to the original point – in my experience, most of my patients do just as well on the generic versions of their medications. Unfortunately I’ve had some for whom the generic was a negative experience. The most common things I’ve seen have been with sertraline (generic Zoloft) and buproprion (generic Wellbutrin). I’ve had a very few have a return of their depression when switching to sertraline and a few experienced ringing in the ears with buproprion. I emphasize this as happening only with a few patients out of many on these medications, but it’s been enough for me to reach the disappointing conclusion that for some medications, brand name does matter.

I still don’t think people should refuse to take generics, because it may not make a difference and the price differential is so great that it could be very expensive to refuse all generics to avoid the small chance that it generic may not work for you. Also, there may be a difference in quality of sertraline depending on the manufacturer and it’s hard to keep up with which company produces the version that works differently.

What’s the conclusion? If you switch to a generic or start a generic drug, you and your doctor should keep an eye out for a change in your status. Also, if you start on a new medication and it doesn’t seem to work or has bad side effects, think about whether switching to the brand version to see if it makes a difference before abandoning the drug.