Summary Safety Review - Interferon beta products - Assessing the Potential Risk of Pulmonary Arterial Hypertension
November 2, 2016 - updated November 30, 2016
Interferon beta-1a (Avonex and Rebif) and interferon beta-1b (Betaseron and Extavia)
Potential Safety Issue
Risk of high blood pressure in the arteries which carry blood from the heart to the lungs (pulmonary arterial hypertension)
- Interferon beta products are used to treat some forms of multiple sclerosis, a disease of the central nervous system.
- Health Canada carried out a safety review, after the European Medicines Agency found a possible link between the use of interferon beta products for treating multiple sclerosis and the risk of high blood pressure in the arteries which carry blood from the heart to the lungs (pulmonary arterial hypertension).
- Health Canada's safety review concluded that there was a possible link between the use of interferon beta products for multiple sclerosis and the risk of developing pulmonary arterial hypertension. The Canadian product safety information for interferon beta products has been updated to include the risk of this side effect.
Health Canada carried out a safety review regarding the risk of pulmonary arterial hypertension associated with the use of interferon beta products after a report from the European Medicines Agency found a possible link between them. Pulmonary arterial hypertension is potentially life-threatening if untreated. Cases of pulmonary arterial hypertension in patients treated with interferon beta therapies to treat multiple sclerosis have been reported in safety reports received from the manufacturers and in published case reports.
Use in Canada
- Interferon beta products are used to treat multiple sclerosis.
- Two types of interferon beta products are authorized for sale, by prescription only, in Canada: type 1a (Avonex and Rebif) and type 1b (Betaseron and Extavia).
- The first of these (Betaseron) was marketed in Canada in 1995.
Safety Review Findings
- At the time of the review, there were 2 Canadian cases of pulmonary arterial hypertension that were possibly related to interferon beta use, and in both cases, the patients improved with treatment of the pulmonary arterial hypertension, and stopping interferon beta use.,
- Worldwide, there were 136 case reports of pulmonary arterial hypertension in patients that were using interferon beta (which includes the 2 Canadian cases). In 14 cases, the pulmonary arterial hypertension may have been related to interferon beta use. In the remaining cases, the information available was too limited to make any conclusions.
- At the time of the review, information regarding the risk of pulmonary arterial hypertension was not included in the Canadian product safety information for any of the interferon beta products.
Conclusions and Actions
- Health Canada's safety review concluded that pulmonary arterial hypertension is a very rare side effect of interferon beta use. Given the potentially life-threatening effects of pulmonary arterial hypertension, healthcare professionals and patients should be made aware of this risk.
- Health Canada has worked with the manufacturers to include the risk of pulmonary arterial hypertension in the Canadian product safety information for interferon beta products.
- Health Canada will continue to monitor side effect information involving interferon beta products, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.
The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what are known about the use of this product both in Canada and internationally.
For additional information, contact the Marketed Health Products Directorate.