A lawsuit over the anti-seizure drug Neurontin began in the United States on Monday, with patients, insurance companies and unions accusing the drug manufacturer of aggressively marketing it as pain medication, an unapproved use.

Neurontin, also known by its generic name gabapentin, is approved for use in Canada and the United States to help control epileptic seizures.

Doctors in both countries prescribe gabapentin to control pain. Canadian doctors wrote two million prescriptions for the drug or its generic versions in 2009.

In 2004, Pfizer subsidiary Warner-Lambert settled a lawsuit filed by federal and state drug programs over the marketing of gabapentin, admitting it fraudulently promoted the drug. Pfizer paid $430 million US in penalties and fines, including $152 million to reimburse the drug programs, which had covered the drugs.

In Monday's suit, a new group of claimants says Pfizer misrepresented the drugs as a painkiller and understated its risks.

The drug may help one in four or five people who take it for chronic pain, but it often causes severe weight gain and grogginess, said Dr. Harry Pollett of North Sydney, N.S., who specializes in treating chronic pain.

"It's a so-so drug that can be very helpful in some cases, but it's not all that helpful in a lot of cases," Pollett said.

Gabapentin class action in Canada

On Friday, Justice Paul Perell of the Ontario Superior Court ordered that a lawsuit relating to Neurontin be certified as a national class action except for residents of Quebec.

The London, Ont., law firm Siskinds LLP and the law firms of Dunn and Company and Hanson Wirsig Matheos in Vancouver, are representing the plaintiffs.

Siskands said the court will determine:

  • Whether Neurontin is ineffective and/or defective or unfit for the purpose for which it was intended and sold.
  • Whether Pfizer breached a duty to warn people or materially misrepresented any of the risks of harm from using Neurontin.
  • Whether the class can choose to require Pfizer to account for all or part of the gross revenue or net income received from the sale of the drug.

"We are disappointed with the court's ruling but are gratified that the court struck plaintiffs' claims of improper marketing and promotion of Neurontin," Heather Bisset, manager of corporate communications for Pfizer Canada, said in an email.

Perell also rejected the plaintiffs' efforts to make Pfizer Canada and Pfizer Inc. responsible for sales of gabapentin, the generic version of Neurontin.

In the 2004 suit, the company admitted promoting gabapentin for unapproved uses, including pain, psychiatric conditions and migraine.

Seeking $4 billion

In the civil suit that began in Boston on Monday, patients, insurance companies and unions argued they should be paid back about $4 billion US.

"Even after they lose a $450-million lawsuit, (the drug) still gets widely used and is almost certainly doing more harm than good," Dr. Gordon Guyatt, a professor in the department of clinical epidemiology and biostatistics at McMaster University in Hamilton, said in an interview. "That is clearly a very unsatisfactory response to the situation from the patient's point of view."

Pfizer Inc. disputes the allegations in the lawsuit, saying Neurontin has been used to treat millions of patients safely and effectively.

"This is a case of an insurance company, Kaiser, seeking its money back for a medicine that provided therapeutic value and that its own physicians prescribed using their best medical judgment," Pfizer said in a statement on the off-label use of the drug.

Canadians and their health plans bought $129 million worth of Neurontin and its generic versions in 2009, according to IMS Health, a company that tracks prescribing.

Glen Hutzul of Toronto has tried many medications, including Neurontin, for the chronic pain he's had since a fall eight years ago. Neurontin didn't work for him.

"It seemed when I took the gabapentin the pain became worse in my shoulder," said Hutzul, who, among other things, sings with the choir Guys Like Us to keep his mind off the pain.

Canada has rules

It is illegal in Canada to aggressively market drugs for off-label use — use of a marketed health product for something other than what's indicated on the authorized product label, Health Canada said.

Health Canada oversees the regulation of drugs but has no jurisdiction over how health-care professionals prescribe drugs once they are approved. Health-care professionals use their own medical discretion in prescribing and rely on information from the product label, medical journals, reports or peer-reviewed studies.

Pollett, the Nova Scotia pain doctor, recalled the sales pitch he received at a pain conference in the U.S.

"We were definitely wined and dined and given the big hard sell that we should be using this for pain," he said. "It made it sound like if we weren't using this for pain we weren't really practising good medicine."

Drug company trials have shown that Neurontin reduces pain. But a paper published in the New England Journal of Medicine in November 2009 said the company manipulated the research, burying unfavourable findings and twisting data to make the drug look more effective than it is.

Patients are "desperate for meds, and docs get told that these drugs work, so they prescribe them," said Jocelyn Downie, Canada research chair in health law and policy at Dalhousie University in Halifax.

Both Guyatt and Downie called for greater regulatory oversight by Health Canada on aggressively promoting drugs for off-label use.

"It's falling between cracks, regulatory cracks," Downie said.

"Some increased monitoring and some increased regulation of off-label use would be appropriate," Guyatt said.