March 2014

Canada’s off label drug problem

In January 2014, the Senate’s Standing Committee on Social Affairs, Science and Technology released its report on the off-label use of prescription drugs in Canada. This report forms the third phase of a four-phase study on prescription drugs in Canada that’s examining clinical trials and medication access, post-approval monitoring of patient safety and drug effectiveness, and the “unintended consequences” of pharmaceuticals.

When Health Canada approves a drug for sale, the drug approval specifies “the population for whom the drug can be prescribed, the indication(s) the drug can treat and the dosage(s) that can be administered.” The prescribing and use of a drug outside of these parameters is deemed “off-label use.”

Off-label use of approved drugs is quite common, and drugs are often used in a broader scope or context than those originally approved. The report indicates that rare diseases are the most common conditions treated with off-label uses of prescription drugs, but because of the small number of patients suffering from rare diseases, this represents a small proportion of overall practice. A recent study published in the Archives of Internal Medicine suggested that 11% of all drugs prescribed are for conditions or circumstances that fall outside their Health Canada approval.

Older drugs are more likely to be prescribed off-label than newer drugs. These older drugs have generally come off patent and are already in competition with generic versions in the market. As a result, there is little incentive for the manufacturers of these older drugs to incur the costs associated with filing changes to their product monograph with Health Canada and amending their approval to include the off-label use.

The concern with off-label drug use is really twofold: patient safety and therapeutic effectiveness.

On the patient safety side, the study turns its focus to populations that are most frequently prescribed off-label medications: pregnant and nursing women, children and seniors. These populations receive the majority of off-label scripts because they were not included in the clinical trials required for approval of the drug in the first place and are therefore not included in the approved indications. However, these are vulnerable populations, and the cost of impaired safety is high. The study states that 75% of medications prescribed to children are actually being prescribed off-label. Of particular concern within this group was the practice of prescribing antipsychotics off-label to children for the treatment of behavioural issues such as attention deficit/hyperactivity disorder and autism. Concurrently, prescriptions for antipsychotics have escalated rapidly over the past 10 years,
with Health Canada issuing warnings of serious adverse reactions when these drugs are used by young children and adolescents at the same time. And, in all populations, a patient receiving a prescription may have no idea that that prescription is for a drug that was never approved for the reason they were prescribed it, or that there may be increased risks or additional adverse reactions associated with it as a result.

The therapeutic effectiveness of off-label drug use is also in question. While in some circumstances such as cancer treatment, there is reasonable evidence to suggest that a specific drug can be used to treat a broader spectrum of sites or stages of tumors beyond its original approval, and can lead to innovative new uses that literally save lives. The Archives of Internal Medicine study found, however, that 79% of the time, drugs prescribed off-label did not have strong scientific evidence to support the off-label use.

In Canada, there is nothing truly preventing the off-label prescribing of drugs. And, while Health Canada does conduct post-approval audits of drugs to ensure compliance with the Food and Drugs Act, it does not presently have the ability to audit the prescribing practices of Canadian physicians. Prescribing is deemed a practice of medicine issue, and therefore, is regulated by the provinces and territories. What is prohibited is the drug manufacturer promoting the drug for off-label use. There is a fine line, however, between what is “promotion” and what is “information.” Several witnesses reporting to the Standing Committee stated that many physicians are educated about the drug’s uses from pharmaceutical sales representatives. And so, the prescribing physicians themselves may or may not be aware that they are prescribing a drug off-label.

With the exception of pre-authorization drugs, neither provincial drug programs nor insurers presently adjudicate and pay drug claims based on whether they are being used for their approved indications, or whether they are in fact being used off-label.

And today, Canada has no process in place for monitoring off-label drug use. For public and private drug plans struggling to contain increasing drug claims, should their plans cover off-label use prescription drugs? And, if not, how will provincial drug plans and insurers be able to determine whether a drug has been prescribed off-label?

excerpts provided by: Benefits Canada – February 2014 contributing freelance author Kim Siddall.

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