The U.S. Food and Drug Administration (FDA) has reduced the maximum recommended dose of the antidepressant Celexa (citalopram) to 40 mg per day, warning that higher doses may trigger potentially fatal changes in heart rhythm.
The FDA also said that studies showed no benefit in the treatment of depression with doses higher than 40 mg per day.
The revised drug label was based on post-market reports and a clinical trial showing that people taking 60 mg per day of citalopram — a dose that was previously approved by the FDA for certain patients — were at increased risk of unsafe changes to the electrical activity of the heart, a condition known as “prolongation of the QT interval,” compared with patients taking 20 mg of citalopram a day or a placebo.
These electrical-activity changes can lead to abnormal heart rhythms, which can be fatal, the FDA said. Based on the trial data, the agency estimated that a 40-mg-per-day dose of Celexa would be safe.
People at particular risk for QT interval prolongation include those with underlying heart conditions or those who have low levels of potassium and magnesium in the blood.
The new drug labels for Celexa and its generics will no longer allow doses of 60 mg per day and will include a warning about the heart risks. The FDA’s safety communication did not include information about the closely related selective serotonin reuptake inhibitor Lexapro (escitalopram).
For now, the agency recommends that people taking higher doses of Celexa talk to their doctors before making any changes to their medication. Patients taking Celexa should seek immediate care, however, if they experience irregular heartbeat, shortness of breath, dizziness or fainting.
Any adverse events associated with Celexa should be reported to the FDA’s MedWatch program, by phone (800-332-1088) or online. (For other contact information, check out the FDA’s safety communication here.)