Off-label and on-label use of gabapentin didn’t decline until Warner Lambert, the drug’s manufacturer, paid $430 million to settle criminal charges and civil liability related to the off-label marketing of gabapentin in 2004. Warner Lambert was acquired by Pfizer in 2000.
“We found that upward trends in the number of new prescriptions for gabapentin and spending on them continued unchecked during all phases of the Department of Justice’s False Claims Act investigation and were greatest for off-label uses,” wrote the study’s authors. “Not until after the settlement did growth trends in gabapentin use become negative, but this occurred for both on- and off-label uses.”
The study analyzed claims data for about 425,000 Medicare beneficiaries who were enrolled in the Pennsylvania Pharmaceutical Assistance Contract for the Elderly and the New Jersey Pharmaceutical Assistance to the Aged and Disabled programs from 1994 to 2005.
The researchers identified three milestones that may have affected off-label prescribing and spending rates for gabapentin, including the beginning of the False Claims Act investigation in 1996 when the complaint was filed, the date in 2000 when the complaint was unsealed, and the settlement of the case in 2004.
“Because enforcement actions targeting illegal off-label promotion might not have a substantial deterrent effect on prescription rates until after settlement, they should be combined with other efforts to combat off-label promotion,” according to the study’s authors.
The additional efforts recommended in the study include increased resources for the Department of Justice to speed up investigations and steeper financial penalties for drug companies.
The authors noted that Warner-Lambert reported $2 billion in off-label sales for gabapentin in 2004, compared to the $430 million settlement.
The authors provided three reasons why off-label use of gabapentin continued to grow during the prosecution period: The manufacturer continued to engage in off-label marketing, previous off-label marketing efforts created a culture of use among physicians who continued to prescribe the drug, and off-label promotion does not affect physician prescribing practices.