Thank you.
Good afternoon, everyone.
Thank you for the opportunity to appear today. I'm pleased to be here today to speak on the regulatory history of mefloquine.
Malaria is a serious life-threatening illness. Even with modern effective treatments and intensive-care support, as many as 20% of patients die when affected with the most severe form of malaria. Over the past three years, there have been approximately 65 cases of severe malaria per year in Canada. Preventing the infection is an important strategy for reducing malaria's impact on travellers.
Mefloquine is a prescription medication that is recommended as one of the few options for malaria prevention by the Public Health Agency of Canada's expert advisory Committee to Advise on Tropical Medicine and Travel, CATMAT, and by most public health and travel medicine authorities around the world. Mefloquine is a tablet taken by mouth and its once-weekly dosing may help with compliance, compared with other drugs that must be taken every day. These other available options, which include Malarone, doxycycline, and primaquine, are generally as effective in preventing malaria but have serious side effects as well. The benefits and risks of each option should be considered by the prescriber, and ultimately the decision on which drug to prescribe to a particular patient rests with the physician in discussion with the patient.
I would like to now speak about how Health Canada has monitored the safety profile of mefloquine since it came to market in 1993, and how it took steps to update, when needed, mefloquine's safety profile in the Canadian “Product Monograph”, the document listing information about uses, dosing, and side effects.
The side-effect information in the monograph is obtained from clinical trials as well as from market experience with the drug. Rare adverse events are usually only detected after a drug is launched onto the market as more patients are exposed to it. Health Canada relies on several sources of information, including its Canada Vigilance Adverse Reaction Online Database , the published literature, and communications from other regulatory authorities to monitor the safety of marketed drugs.
Through mefloquine's life-cycle, its safety information has been continuously monitored by Health Canada. As such, it has been periodically assessed to determine if current labelling appropriately reflects the drug's safety profile. The original monograph, introduced in 1993, included a warning to advise that patients with a past history of psychiatric disturbance or convulsions should not be prescribed mefloquine for malaria prevention. As a result of post-market adverse drug reaction reports, in January 1997 these warnings were moved into the contraindication section of the monograph.
In 1998, an article was published in Health Canada's Canadian Adverse Reaction Newsletter, describing four reports of neuropsychiatric adverse events with mefloquine use.
This action was followed in 1999 by a safety review that examined all Canadian adverse events in association with mefloquine, which resulted in an addition of suicidal thoughts as a listed side effect. Health Canada also decided at that time to assess all adverse events associated with mefloquine every six months.
Additional information on neurologic and psychiatric adverse events associated with mefloquine, including that they may continue long after mefloquine has been stopped, was added to to the monograph in 2003. This included the addition of a patient-information section as well as a wallet card describing the neurologic and psychiatric side effects and advising patients to consult a physician should these effects emerge. These changes were prompted by a similar update carried out by the U.S. Food and Drug Administration.
In 2005, two related public advisories, a “Dear Healthcare Professional” letter and a “Dear Pharmacist” letter, were issued by the manufacturers of mefloquine in collaboration with Health Canada.
The safety profile and product labelling were formally assessed again in 2006. This review concluded that no additional risk minimization measures were required. The department has since then continued to monitor the safety of mefloquine in a standard manner.
As mentioned before, Health Canada also monitors and assesses the actions taken by other regulatory authorities. In 2013, the U.S. Food and Drug Administration published a risk communication highlighting a boxed warning on neurologic and psychiatric adverse events in the U.S.'s mefloquine prescribing information. Health Canada reviewed the safety data at that time and determined that the safety issues were already adequately labelled in the product monograph.
In 2014, Health Canada introduced its plain language labelling initiative, setting out a new format for the Canadian product monograph. Following this, Health Canada requested that the sponsor update the mefloquine monograph to reflect this new format. The update was completed in August 2016, allowing for a clearer presentation of information. For example, the new product monograph and wallet card now include more prominent boxed warnings indicating that mefloquine may cause neurological and psychiatric adverse reactions that can persist after the product has been discontinued. The box warnings also state that if psychiatric or neurological symptoms occur, mefloquine should be discontinued and an alternative medicine substituted.
To conclude, malaria is a serious, life-threatening infection with a mortality rate of 20% in patients with severe malarial infection. Mefloquine is a very effective antimalarial drug when it's tolerated by travellers and when the drug is prescribed and taken as directed in the product monograph. Health Canada will continue to monitor its risks and take steps to address the safety issues in a timely manner. The benefit/risk profile of mefloquine for malaria prevention based on current information is considered positive.
I would like to thank the committee for the opportunity to speak to you today.
I will now turn to Barbara Raymond, from the Public Health Agency of Canada, to provide her remarks.