British Columbia overdoses on tranquillizers
UBC study finds 170,000 in province use
more pills than experts recommend
CanWest News Service
February 7, 2005
by Sharon Kirkey
Benzodiazepines, potentially addictive tranquilizers that include Xanax and Ativan, are being prescribed to thousands of B.C. residents in amounts 10 times higher than recommended, despite the risk of harm and "scant evidence" of any benefit, University of B.C. research shows.
"Benzos" are prescribed widely to treat anxiety and insomnia, as well as panic attacks. The sedatives, which depress brain function, are intended for short-term use only - two to three weeks - and it's recommended most people take no more than 100 pills a year.
But UBC researchers found 4.2 per cent of the population of B.C. - about 170,000 people - received more than 100 pills in 2002. About 10,000 people in B.C. were prescribed more than 1,000 pills.
Nationally, more than 14 million prescriptions were filled by drug stores last year, says prescription-drug tracking firm, IMS Health Canada.
"The overall benefits and harms from this drug exposure in B.C. is unknown," the researchers report in the most recent Therapeutics Letter, a bi-monthly publication produced by the Therapeutics Initiative, a world-renowned drug research group based at UBC.
Nearly 10 per cent of B.C.'s population (or 400,000 people) received at least one prescription for the sedatives in 2002, putting the drug class near the top in terms of pills dispensed.
Overall, 84 million benzos were prescribed in British Columbia in 2002 - more than the number of acid-suppressing pills, cholesterol-lowering pills, prescription painkillers such as Celebrex, or diuretics.
The two groups most vulnerable to side effects from benzodiazepines - women and the elderly - are the biggest users. But the tranquilizers are also being prescribed to children, even toddlers under four, even though they have not been licensed for use by kids.
The researchers doubt the findings hold true for B.C. only. If anything, the province's population tends to take fewer prescription drugs than other Canadians.
Hailed as "wonder drugs" and "mother's little helpers" when they first hit the market more than 40 years ago, benzodiazepines quickly replaced barbiturates as the top-prescribed anxiety pills because they were far less toxic in overdose.
But, "these drugs are habituating, it's known they tend to lose their effectiveness if used regularly, and you don't want someone to become dependent on them because in that setting it can be extremely difficult to stop," says Dr. James Wright, director of the Therapeutics Initiative.
The Internet is filled with sites on benzo addiction and withdrawal, and Wright's group warned Canadian doctors in 1995 about the dangers of long-term use.
"People who start these drugs are often not warned that, when they do stop, they can expect to have withdrawal effects." These include anxiety, tremors and confusion - symptoms that can last for weeks or months, Wright says. The most common withdrawal reaction is insomnia.
"So, when they stop and they can't sleep, they think they continue to need the drug."
Benzos work by boosting the effect of a brain chemical called gamma-amino butyric acid. The acid acts as the body's "natural tranquilizer" by telling neurons to slow down.
The pills are also prescribed for epilepsy, muscle spasms and to sedate people before surgery.
But the drugs can cause confusion, dizziness, depression, temporary amnesia and "daytime sedation" that can lead to falls, fractured hips and bones and impaired driving. Some researchers have warned there are more "benzo drivers" than drunk drivers.
There are a more than a dozen generic versions on the market. The seven most used benzodiazepines in B.C. were lorazepam (brand name Ativan), clonazepam (Rivotril), zopiclone (Imovane/Rhovane), oxazepam (Serax), alprazolam (Xanax), diazepam (Valium), and temazepam (Restoril).
Five of the drugs have "half lives" (meaning the time it takes for half the original dose to leave the body) ranging from 10 to 100 hours.
"When such long half-life drugs are taken at night, daytime sedation is expected and common," the researchers warn.
Wright's team also found antidepressant use increased by 73 per cent between 1996 and 2002, rising to 124 million pills; benzo use increased by 11 per cent over the same period. Antidepressants are also sometimes used to treat insomnia.
Wende Wood, a psychiatric pharmacist at the Centre for Addiction and Mental Health in Toronto, says there are still legitimate, short-term uses for benzos. But, "If someone is having a lot of problems with insomnia, they should go to their doctor to find out why. It could be pain, it could be depression or it could be anxiety. Just giving them a sleeping pill is like a Band-Aid solution."
HIGH ANXIETY:
The facts about benzodiazepines:
Tranquilizers with more than a dozen generic versions, including Ativan and Xanax
Prescribed to treat anxiety, insomnia and panic attacks
Favoured over barbiturates because they're less toxic in the event of an overdose
Women and the elderly are most vulnerable to side-effects
Withdrawal effects include tremors, confusion and, most commonly, insomnia
