Side Effects of Zoloft Versus Generic Sertraline

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Side Effects of Zoloft Versus Generic Sertraline

Question:

Is there a difference between the prescription Zoloft and the generic version? I started taking Zoloft in 1994, but switched to the generic version over a year ago because it's free with my prescription coverage. I think I've gained weight since the switch. Is it possible that the generic version causes me to gain weight when Zoloft didn't?

Answer:

I can't imagine that the change from Zoloft to the generic form of the drug, called sertraline, has caused your weight gain, assuming you have not changed the dose.

The FDA requires that a generic drug contain exactly the amount of active ingredient as the brand-name drug. For example, a 50 milligram generic sertraline tablet must contain the exact same amount of the active ingredient in a 50 milligram Zoloft tablet.

The generic sertraline probably has a different appearance than the original Zoloft tablets. It may be a different color or shape. Or instead of a tablet, you might be taking a capsule. These differences are related to the inactive ingredients that are used to hold a tablet together and give a tablet its color.

These inactive ingredients can affect the way the active ingredient is absorbed from the intestine into the blood stream. But the FDA requires that any variation in the amount and rate of absorption between a generic and its brand-name counterpart be minimal. So for most medications, including sertraline, these small variations shouldn't change how you respond to the generic product.

However, for some medications it is important that your doctor know if you have changed to a generic. Examples include the blood thinner warfarin (Coumadin), the heart medication digoxin, and thyroid medications. Even small differences in how much of these medications get absorbed can be important. Your doctor will want to give you blood tests more frequently when you first change to a generic because you may need a dose adjustment. And for these medications, once you make the change to a specific generic, tell your pharmacist that your refills should always come from the same manufacturer.

Now, to get back to the weight gain. This probably would have happened even if you were still on the original Zoloft. As we age, our bodies handle drugs differently and you may need to change the dose of sertraline (just as you would have needed to change the dose of Zoloft, had you stayed on the brand-name product). Or perhaps there is another reason for the weight gain, not related to this medication.

Last updated:	March 03, 2009