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How Safe Are KIDS' Prescription Drugs?
Drugs prescribed to children and adolescents have been much in the news lately.Health Canada has issued warnings about some drugs that both patients and physicians trusted,and it has withdrawn others from the market.What's going on?Parents should understand these complicated and confusing issues.
How Are Prescription Drugs Approved in Canada?
When a pharmaceutical company has a new drug.it applies to Health Canada for a licence to sell it.Based oninformation the company provides,including the results of clinical trials,the drug is either approved or the application is rejected.
Is There a Difference in the Way Drugs Are Approved for Children and Adults?
Normally.drugs are tested in adults first.Dr.Denis Daneman.a clinical investigator at The Hospital for Sick Children in Toronto,says,“we have to be remarkably careful because children are physiologically different than adults and are seen by physicians as a highly vulnerable group.”
What Happens Once a Drug Is Approved?
“Once approved,” explains Daneman.“it's available on the market and doctors can prescribe it for any indication they'd like to.” Even if it has not been tested specifically in children.he says.“physicians may start to use it either in small trials or what we call off-label (use of a prescription drug to treat a condition for which the drug has not been approved) in children.”
How Common Is Off-label Use?
Dr.Michael Rieder. director of the Adverse Drug Reaction Clinic at the Children's Hospital of Western Ontario,says,“drugs commonly used in children，such as antibiotcs and asthma drugs,are tested in children.” But,he says,“there is a misconception that children take only those drugs.We did a study looking at a million kids in Canada over a year.It turns out they used l,400 different drugs,of which 60 percent have not been tested,or approved for use in children.”
If a Drug Is Safe in Adults,Why Do You Need to Test It in children?
Health Canada's Dr.Siddika Mithani says.“children are not small adults.”Their physiology is different.That goes for adolescents.too.Dr.Eric Wookltorton.an Ottawa-based family physician who writes a column on adverse events for the Canadian Medical Association Journal,says,“Depo Provera is an injectable birth-control product used by women of all ages.No one thought to test it in adolescents until recently.Teenagers arelaying down bone density and this drug decreased bone density.”
Are Older Drugs Safer?
“If I were to use a medication off-label that's been around for some time,I'd be less concerned about it.” advises Dr.Peter Nieman.a Calgary pediatrician.“But if you use a medication that's being promoted as che best thing since sliced bread,and you know it's fairly new and are using it off-label,you are a bit nervous.”
How Many Side Effects Are Reported?
In 2004 Health Canada received 10,238 reports of adverse reactions in people of all ages.The number of reports has been increasing since 1999,when just under 6,000 were sent in.However.Dr.Bruce Carleton.of the pharmaceutical outcomes program at the Children's and Women's Health Centre of British Columbia，says,“95 percent of negative reactions are never reported.”Wooltorton explains:“how do you track the more minor,long-term side effects,the ones where kids are a little bit stunted in growth or they are having learning problems in school.There's no regulation and no financial incentive to report anything at all.”
Should We Be More Careful with Some Drugs?
Dr.Jack Uetrecht,a Canada Research Chair in adverse drug reactions,advises extra caution with drugs that affect the central nervous system.“The effects and long-term outcomes of giving these types of drugs aren't totally understood. Make sure the appropriate tests are given to make as clear a diagnosis as possible.and that the appropriate treatment is given based on that diagnosis.Talking to the patient for a few minutes and prescribing a drug would not be the best method.If there is a severe clinical problem and a clear clinical benefit,then the benefit is worth the risk.”
Can Side Fffects Be Prevented?
If your child has had a reaction to a drug in the past,an allergist can advise if she is still allergic.and if so,what could be used instead.Genome Canada is funding an $8.4-million research project that may helpprevent side effects in the future.led by Carleton and geneticist Michael Hayden,director of the Centre for Molecular Medicine and Therapeutics.It is looking for genetic markers that would signal if a child was at risk for an adverse reaction.“There are genetic differences in the way a lot of physiological processeshappen in the human body,”says Carleton.“It makes sense that those differences would affect the way we process drugs.Therefore,understanding when that situation exists would help us to construct better guidelines.”
What Should You Ask About Your Child's Prescription?
First,be sure it is really necessary,says Wooltorton.“A lot of children don't always need prescriptions for a lot of things.Ear infections are an example of when antibiotics are sometimes,but not always,necessary.But there is a tendency in our society to want our kids to be like us.We want to get back to work.We want them to get back to school.We want a quick fix.But‘how wi11 we know the drug is working?'A child with asthma,for example,is usually given a couple of medications.One will be to open the airways.He should feel better after the First dose.If he doesn't,we have a problem.The other medication is used to reduce inflammation.This will decrease the number of acute breathless episodes,but it takes time to have an effect.”Find out how long your physician has been using the drug,says Rieder,and what the experience has been like.Your doctor may know quite a lot about the drug, even if it is being used off-label.
What Should Parents Watch Out for?
Dr.Michael Kramcr,of the Canadian Institutes of Health Research,says you should contact your physician“ifyour child is very sleepy or is agitated and unable to sleep.You should also be concerned about any rashesthat cause blistering or hivcs.”When you pick up a medication at the drugstore,it often comes with a listof potential side effecfs.Maura MacPhee,who teaches in the School of Nursing at the University of British Columbia,says,“this is generic information.Before leaving the physician's office,make sure you know what side effects are the ones you need to worry about with your child.”
How Safe Is the System?
In the last 25 to 30 years,we have seen significant advances in the treatment of childhood leukemia.“WhenI was training 30 years ago,”says Daneman,“childhood leukemia had an 80-percent mortality rate;now the survival rate is better than 80 percent.”Another important development:More drugs are being tested now in children.Daneman says:“if you look at the number of studies that go on,there are many more in the last five to eight years than there were 20 0r 30 years ago.”
