A new study has unveiled the extent to which Parke-Davis – now part of Pfizer after its acquisition of Warner-Lambert - promoted its epilepsy drug Neurontin (gabapentin) for off-label uses. Pfizer was forced to pay in excess of $430 million in 2004 to settle claims relating to the government’s investigation into the sales and marketing of its $2 billion a year drug.

The agreement brought to an end a 1996 lawsuit against Warner-Lambert's Parke-Davis subsidiary that claimed the company illegally promoted Neurontin on at least 13 separate conditions for conditions the drug was not approved to treat. Parke-Davis is said to have used illegal cash gifts for doctors, as well as other ploys, to buoy sales of the drug for these non-approved uses.

Now this new study, led by researchers at the University of California, San Francisco, and the San Francisco VA Medical Center, says the company conducted a host of activities – such as sponsored consultants’ meetings and medical education forums – that would generally be perceived by doctors to be unbiased but were instead used to encourage the prescription of Neurontin, often at doses or for uses for which it had not been approved. Tactics included sponsoring a large medical meeting to promote higher-than-approved doses, discouraging the publication of negative research results, and sponsoring apparently independent scientific publications. Many of these activities were organized through third-party companies paid by Parke-Davis through “unrestricted educational grants,” say the authors, adding that, while this created an aura of independence, in fact there were “extensive ties with Parke-Davis.”

When the lawsuit was filed – by a former employee – Neurontin was only available for the secondary treatment of a specific form of epilepsy but, claims the report, Parke-Davis promoted it “for pain, psychiatric conditions, migraine and other unapproved uses” [which] “by the end of the decade accounted for nearly nine out of every 10 prescriptions for the drug.” Currently, doctors are allowed to prescribe off-label, but pharmaceutical companies are prohibited from promoting these unapproved uses.

Says lead author Michael Steinman, assistant professor of medicine at UCSF: “It appears that many educational and scientific activities were twisted by promotional influence and were no longer truly independent or objective. This is dangerous, since physicians may be largely unaware of the bias to which they are being exposed.” He concludes: “the current system for separating commercial from scientific speech is inadequate. A self-regulatory approach has not worked. There are enormous loopholes through which commercial content can influence the course of medical debate.”

The paper appeared in the August 15th issue of the Annals of Internal Medicine.