Too many Canadian women taking a powerful acne medication are not following guidelines to avoid pregnancy while taking the drug, putting themselves at risk of delivering a child with severe birth defects, according to a new study.
Isotretinoin, sold under the brand name Accutane as well as in generic form, has been available for use in Canada since 1983. The drug is a vitamin A derivative called a retinoid that helps prevent acne by reducing production of an oily skin substance called sebum.
While the drug is effective, it can also severely harm a developing fetus, causing malformations of the head and face, cardiac and central nervous system defects, as well increase the likelihood of miscarriage or the need for a medical termination.
Because of the risk of birth defects, Canada has a pregnancy prevention program in place so that women taking the drug are fully informed of the risks.
The program calls for patients starting the drug to provide two negative pregnancy tests, written consent that they understand the risks, and agree to use two reliable birth control methods while they are under treatment.
But a new study in this month鈥檚 finds that as many as 30 to 50 per cent of women taking the drug do not comply with the program鈥檚 requirements.
The researchers looked at patient records for more than 59,000 Canadian women aged 12 to 48 years taking isotretinoin between 1996 and 2011.
Over the 15 years, there were 1,473 pregnancies. Only 118 of these pregnancies resulted in live births, and of them, 11 of the babies were born with birth defects.
One of the study鈥檚 authors, Brandace Winquist, a research consultant with the Saskatchewan Health Quality Council, says if all of the recommendations of the pregnancy prevention program are followed, many, if not all, pregnancies can be avoided.
鈥淲hen they aren鈥檛, these mothers are put into difficult situations 鈥� situations that represent ethical dilemmas. And these dilemmas are very much avoidable with good clinical practice,鈥� she told 麻豆传媒 from Swift Current.
The researchers found that only one-quarter to one-third of women taking the drug also obtained birth control prescriptions. However, they note that they were not able to track the use of birth control pills obtained from free clinics or elsewhere, nor could they track the use of other birth control methods, such as intrauterine devices or condoms.
The study鈥檚 lead author, Dr. David Henry, a senior scientist at the Institute for Clinical Evaluative Sciences (ICES) and co-lead of the Canadian Network for Observational Drug Effect Studies (CNODES), says the pregnancy prevention program is only partly effective.
He says its effectiveness rate hasn鈥檛 improved in the 15 years that Accutane has been available in Canada and that both patients and doctors need to take isotretinoin鈥檚 risks seriously.
鈥淚t is the responsibility of doctors and pharmacists to ensure that these drugs are prescribed and dispensed safely and it鈥檚 the responsibility of patients to use them properly,鈥� he said.
Henry said it鈥檚 also worrying that many women prescribed isotretinoin don鈥檛 appear to be trying other prescription acne medications that might be safer for them to take.
鈥�(Isotretinoin) should only be used in severe scarring cases of acne,鈥� Henry said. 鈥淭his has been known a long time. And the price you pay for an effective therapy in that situation is to properly adhere to the program,鈥� said Henry.
Toronto dermatologist Dr. Paul Adam said that both doctors and patients need to be more careful with Isotretinoin.
鈥淚 had one case of a girl (seeking the drug) who said she hadn鈥檛 had sex in a long time, and when we went and did the baseline testing, she was already pregnant and didn鈥檛 know it,鈥� he said.
鈥淚f I feel the patient isn鈥檛 able to to carry out their part of it, I don鈥檛 give them the medication,鈥� he added.
A spokesperson for Health Canada said the agency is reviewing the results of the study 鈥渁nd will take appropriate action as needed upon completion of its review.鈥�
A spokesperson for Health Canada said the agency is reviewing the results of the study 鈥渁nd will take appropriate action as needed upon completion of its review.鈥�
With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip
