Sleep attacks associated with Parkinson's drugs

Health Canada has sent out warnings about two drugs used to treat Parkinson's disease. They say the drugs can cause sudden sleep attacks.

Studies dating back to 1999 show links between pramipexole (Mirapex) and ropinirole (ReQuip) and sleep attacks.

A recent study by the University of Manitoba found 21 out of 420 patients using the medications reported dozing off at the wheel. The study was supported by Boehringer, the manufacturer of Mirapex.

The study has been published in the most recent issue of the Journal of the American Medical Association.

As a result, Health Canada has directed the drugs' manufacturers, Boehringer and GlaxoSmithKline, to send letters to physicians to warn patients "not to drive or engage in other activities where impaired alertness could put themselves and others at risk of serious injury or death."

The letter obliges physicians in most provinces to inform the motor vehicle authorities when they prescribe the drug to a patient.

"This is a major problem, because these are the drugs we want to use in patients while they're still young with Parkinson's disease," says Dr. Douglas Hobson of the University of Manitoba.

"These are patients are still functioning and... doing well working, and if you suddenly tell them they can't drive, it's a huge issue for them."

Provinces have different rules regarding medically unfit drivers.

Outright ban on driving inappropriate

Doctors have to tell departments of motor vehicles in Manitoba, New Brunswick, Newfoundland andLabrador, the Northwest Territories, Nunavut, Ontario, Prince Edward Island, Saskatchewan and Yukon, when they prescribe these drugs.

Discretionary reporting is the rule in Quebec and Nova Scotia.

In Alberta, it is at the discretion of the physician but mandatory for the patient to report the change in their medical condition.

For British Columbia, there's a blanket prohibition in the province for people on these drugs to drive.

In Manitoba and Ontario, transportation departments assess each case individually before deciding whether to prohibit the person from driving.

The study says doctors can assess if their patients are prone to sleep attacks by using something called an "Epworth Score."

"(It's) a standardized assessment of how sleepy a person would be," says Hobson. "Patients can complete it in the waiting room and then bring it in for the physician to reviews."

Hobson says an outright ban on driving would be inappropriate. He says doctors have enough information now to pick "who is safe to drive and who isn't."

The Parkinson's Society is hoping to meet with Health Canada and provincial motor vehicle departments to issue new recommendations regarding the drugs and driving.

The society says people are actually refusing to take the drugs they need because they're reluctant to give up their driving privileges.