Malaria is a serious, potentially life-threatening infection with a mortality rate of 20% in patients infected with the most severe form. However, recently there have been some questions raised regarding the safety of mefloquine, one of a few drugs used to protect Canadians — civilian and military — from malaria when travelling to areas with a high infection risk.

Malaria life cycle/CDC
Malaria life cycle/CDC

Protecting the health and safety of Canadians, including members of the Armed Forces and Veterans, is a top priority for Health Canada. That is why Health Canada launched a safety review of mefloquine at the end of 2016.

As part of the review, Health Canada examined all available scientific and medical information, including previously reviewed evidence, to determine whether there is a potential link between the use of mefloquine and rare long-term and permanent neurological and psychiatric adverse events. Health Canada also examined whether certain individuals could be at increased risk of experiencing these long-term adverse events.

Health Canada’s safety review concluded that:

  • Although some cases have been reported, there is no conclusive evidence that mefloquine can cause long-lasting and permanent neurological and psychiatric adverse events;
  • some individuals were prescribed mefloquine even though they had contraindications against its use such as past or ongoing neurological or psychiatric conditions; and
  • there were a small number of reported cases of permanent damage to the vestibular system in the inner ear, which controls balance.

Mefloquine remains a first-line option to prevent malaria in the general population. The safety review found that the current product label for mefloquine contains the relevant information on the safe and effective use of the drug. As the label describes the potential for neurological and psychiatric adverse events, including those that are long-lasting and those related to permanent vestibular damage, no changes are needed in that regard.

However, Health Canada will work with the manufacturer to add a checklist about the contraindications to the use of mefloquine to the product label to support healthcare professionals when they prescribe this medication to patients. Health Canada will also work with the manufacturer to update the Patient Medication Information section to more clearly explain to patients the type of neurological adverse events that may, very rarely, become permanent in some patients. These adverse events are related to the vestibular system and include permanent dizziness, vertigo, tinnitus or loss of balance.

Health Canada will be informing Canadians and healthcare professionals once the product label updates have been completed. Considering the seriousness of malaria, the benefits of mefloquine continue to outweigh its risks.

In addition to Health Canada’s safety review, the Canadian Armed Forces will be announcing the release of the findings from its Surgeon General’s Review on the Operational Use of Mefloquine. Veterans Affairs Canada is also aware of this issue.

The Canadian Committee to Advise on Tropical Medicine and Travel is also currently reviewing the recommendations for the use of anti-malarial drugs, including mefloquine. The Public Health Agency of Canada will consider any updated recommendations from the Committee in its advice to Canadian travellers, as appropriate‎.

As with all other prescription drugs, Health Canada will continue to monitor the safety of mefloquine and will take further action as necessary to protect the health and safety of Canadians.