Summary Safety Review - Loratadine - Abnormal heart rhythm (QT interval prolongation)

November 09, 2016

Product

Loratadine

Potential Safety Issue

Abnormal heart rhythm (QT interval prolongation)

Key Messages

• Loratadine is available as an ingredient in some over-the-counter (OTC) products used for the relief of symptoms of allergy.
• Health Canada carried out a safety review following international reports of abnormal heart rhythm (QT interval prolongation) suspected of being associated with the use of loratadine.
• After review of available data, a link between the use of loratadine and the abnormal heart rhythm could not be established. Health Canada will continue to monitor the safety of loratadine containing products.

Overview

Health Canada carried out a safety review to investigate the potential risk of developing an abnormal heart rhythm (QT interval prolongation) with the use of over-the-counter (OTC) drug products containing loratadine. This safety review was triggered by a publication, in the World Health Organization (WHO) Pharmaceuticals Newsletter^{Footnote 1}, describing cases of an abnormal heart rhythm (QT interval prolongation) possibly associated with the use of loratadine and desloratadine.

Use in Canada

• In Canada, loratadine is an ingredient found in some OTC drug products that relieve symptoms of seasonal allergy or allergy caused by pollen or dust (hay fever) such as sneezing, runny or itchy nose, itchy watery burning eyes, as well as allergic skin conditions.
• Loratadine has been marketed in Canada since 1988 under the brand name Claritin. Generic versions are also available. It is available in tablets or syrup.

Safety Review Findings

• At the time of the review, Health Canada had received 21 Canadian reports of abnormal heart rhythm (QT interval prolongation) suspected to be associated with loratadine use. Of these, 4 cases were further assessed. The review of these 4 cases could not conclude whether loratadine played a role in the abnormal heart rhythm. The information contained in the reports was limited, and some patients may have had other underlying heart conditions or were taking greater than the recommended dose of loratadine.
• In addition, Health Canada reviewed 81 international reports, of abnormal heart rhythm with the use of loratadine, that were provided by the manufacturer. A link between these cases and the abnormal heart rhythm could not be established, due to other risk factors which may have played a role, or there was not enough information in the reports to draw conclusions.
• Also, a search in the World Health Organization’s Adverse Drug Reaction Database (VigiBase) found 101 cases of abnormal heart rhythm suspected to be associated with loratadine use.  A link between the use of loratadine and the abnormal heart rhythm could not be established, because there was not enough information in the reports to draw conclusions.
• Scientific studies have shown that loratadine was not associated with abnormal heart rhythm in humans

Conclusions and Actions

• After review of available data, a link between the use of loratadine and the abnormal heart rhythm (QT interval prolongation) could not be established.
• Health Canada will continue to monitor safety information involving loratadine, 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.

Additional Information

The analysis that was carried out for this safety review took into consideration information from scientific and medical literature, Canadian and international adverse reaction reports as well as what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.