Pharmacogenomic information in the Warning section of drug labels: A comparison between labels in the United States and those in five other countries/regions.

WHAT IS KNOWN AND OBJECTIVE: Clinically validated pharmacogenomic information useful for patient selection and/or dose adjustment is included in drug labels. However, the label information may differ among countries. This commentary summarizes the pharmacogenomic information on drug labels in different countries.

COMMENT: We selected six drugs, namely, clopidogrel, atomoxetine, irinotecan, mercaptopurine, abacavir and carbamazepine and compared the pharmacogenomic information in the "Warning" section of these drug labels in the United States and 5 other countries/regions.

WHAT IS NEW AND CONCLUSION: The pharmacogenomic information in drug labels is not well harmonized across countries/regions, possibly due to differences in population characteristics such as relevant allele frequencies, variable genetic test availability and differences in insurance coverage. Further and periodical investigations of this issue would be useful.