Summary Safety Review - Antidepressants - Assessing the Potential Risk of Serious Eye Disorder (Angle-Closure Glaucoma)

August 12, 2016

Product

Antidepressants

Potential Safety Issue

Angle-closure glaucoma

Key Messages

• Antidepressants are drugs used for the treatment of depression, anxiety, obsessive compulsive disorder, insomnia, and post-traumatic stress disorder, among many other conditions.
• Health Canada carried out a safety review when it became aware that the U.S. Food and Drug Administration (FDA) was investigating the risk of angle-closure glaucoma linked to antidepressant use.
• Health Canada’s review found a link between antidepressant use and the occurrence of angle-closure glaucoma. Health Canada is therefore working with manufacturers of antidepressant products to update the Canadian product information to include a warning of the potential risk for angle-closure glaucoma with the use of antidepressants.

Overview

Health Canada carried out this safety review when it became aware that the FDA was investigating the risk of angle-closure glaucoma linked to antidepressant use. Angle-closure glaucoma is a serious eye disorder where eye fluid drainage is blocked, leading to a sudden increase in the pressure in the eye and causing pain and blurred vision. If not treated immediately, angle-closure glaucoma can lead to permanent vision loss.

The safety review was carried out to determine whether the information available on angle-closure glaucoma included in the Canadian product information for antidepressants was accurate and in agreement with the current scientific evidence.

Use in Canada

• Antidepressants are widely used drugs that have been available on the Canadian market since the 1950s for the treatment of depression, anxiety, obsessive compulsive disorder, insomnia, and post-traumatic stress disorder, among many other conditions.
• The safety review focused on the following 23 antidepressant medications available in Canada: desipramine, imipramine, clomipramine, doxepin, trimipramine, amitriptyline, nortriptyline, maprotiline, mirtazapine, phenelzine, moclobemide, tranylcypromine, fluoxetine, citalopram, paroxetine, sertraline, fluvoxamine, escitalopram, venlafaxine, duloxetine, desvenlafaxine, trazodone, and bupropion.
• Prescriptions for antidepressants in Canada have been increasing since 2009 at an average rate of 5.6% per year. An estimated 40.5 million prescriptions of antidepressants were dispensed in 2013.

Safety Review Findings

• At the time of the review, there were 163 reports of angle-closure glaucoma linked with the use of antidepressants from different sources. Health Canada received 2 of these reports through the Canada Vigilance Program.
• At the time of the review, there were 2226 reports of pupil dilation linked with the use of antidepressants from different sources. Health Canada received 130 of these reports through the Canada Vigilance Program. Pupil dilation is a well-known risk factor that may lead to angle-closure glaucoma in certain patients (patients who have narrow eye fluid channels).
• Based on the review finding that there was no difference in the level of risk for angle-closure glaucoma among the different antidepressants reviewed, it was recommended that the potential risk of angle-closure glaucoma be listed in the product information for all antidepressants.

Conclusions and Actions

• Health Canada’s review found a link between antidepressant use and the occurrence of angle-closure glaucoma.
• Health Canada is working with manufacturers of antidepressant products to update the Canadian product information to include a warning of the potential risk for angle-closure glaucoma with antidepressant use.
• Health Canada will continue to monitor safety information involving antidepressants, 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 contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.