Don't Rely on the Label

Generic brand medications with multiple labels may have incorrect or outdated information

(RxWiki News) Yes, generic brands are cheaper and contain the same ingredients. But be wary of the safety information provided on those medicines when shopping.

Safety warning labels differ in more than two-thirds of generic brand drugs compared to the same brand-name drug, a recently published study has found.

"Ask your doctor about the side effects with any Rx."

Researchers, led by Jonathon Duke, MD, MS, from the Regenstrief Institute and assistant professor of medicine at the Indiana University School of Medicine, looked at over 9,105 product labels for more than 1,500 drugs.

They tracked adverse reactions to drugs through the FDA's Structured Product Label format, which is currently the required form of labeling available in over 85 percent of prescription medications. Then they measured how closely labels for the generic product lined up with the brand name.

Almost a third of the drugs have just one label and more than 40 percent have two to five labels. The remaining drugs have six or more labels with 3 percent of all drugs using more than 25 labels.

The 25 drugs that had the greatest discrepancies among its labels were further analyzed to find out what caused the errors.

Researchers found that 68 percent of these drugs had errors in the safety information, including missing tables, formatting issues and outdated post-marketing reports. One case had completely wrong drug information.

Most of these label differences were relatively small, but 9 percent of them had differences in more than 10 side effects compared to the brand name label.

Dr. Duke said that pharmacists and doctors, who often convey the information to patients, need to know how the drug interacts, side effects and other safety issues when patients pick up the prescription.

“Physicians frequently use labeling information, either directly or indirectly, to make prescribing decisions,” he said in a press release.

"We found that generic drug labels may contain incomplete or incorrect safety information. Until this problem is resolved, physicians and patients should rely on brand drug labeling only, even when the patient is getting a generic version of a drug.”

On average, a given drug had more than four deviations in the label. And overall, almost 78 percent of generic manufacturers had labels different from those of the brand name.

The brand name manufacturer checks how safe the medication is before it hits the pharmacy shelves and the FDA does not require the generic manufacturer to repeat the safety tests on its product.

Researchers said that using a centralized list of drug side effects kept by an independent source might help with the label inconsistencies.

"Drug labels would simply reference this common repository rather than attempting to maintain all the information within a single document,” Dr. Duke said.

"Clinicians could refer to this resource for the most up-to-date safety information regardless of generic manufacturer."

The authors note they gathered information solely from the FDA's online database rather than the actual paper labels, which may skew results. They also did not look at the precautions listing or the Boxed Warning data.

The study, which was funded by the Regenstrief Institute, was published online October 8 in the journal Pharmacoepidemiology and Drug Safety and will be published in a future print issue. The authors report no conflicts of interest.

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Review Date: 
December 18, 2012