Safety labeling on generic drugs is inconsistent, study saysBMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e8650 (Published 21 December 2012) Cite this as: BMJ 2012;345:e8650
Generic drugs are required by US law to carry safety warnings on their labels identical to those on the branded drugs, but a new study shows that 68% of the time there were inconsistencies between the two.1
The study used software to extract and compare electronic versions of all package inserts in the Food and Drug Administration’s DailyMed repository, a total of 9105 product labels as at September 2010, representing 1540 separate drugs. A single company produced both the branded and the generic versions of 500 of these drugs.
About two thirds of the drugs whose generic and branded versions were produced by two or more companies (711 of 1040 compounds) “showed some discrepancies within the labeling,” the study found. Labels had an overall mean of 4.4 adverse drug reactions and a median of 0.8. Measuring the range between the maximum and minimum number of possible adverse events reported on the label, the researchers found a mean of 12 and a median of 2. “These results indicated that the majority of drugs showed relatively small differences across their labels, while a smaller number of medications showed significant variation,” they said.
The greatest variation was seen in drugs produced by 10 or more companies.
The Indiana University School of Medicine researchers manually examined a sample of labels with the greatest divergence to better understand why. Often it was because the generic product carried a more limited label indication, while a branded drug carried additional indications that were still under patent protection.
“If physicians do not verify the presence of the intended indication when reviewing a generic label, they may inadvertently miss indication-specific safety data that is absent in one version of the label but present in another,” they said.
Because a branded drug generally is supported by the broadest scope of clinical study and is the most current information, the authors urged clinicians to review the brand label information even if they are prescribing the generic version.
The study was quantitative in nature and did not attempt to evaluate the qualitative nature of differences in labeling or their clinical significance.
Cite this as: BMJ 2012;345:e8650