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NEW WARNINGS ABOUT HEART RHYTHM PROBLEMS WITH THE ANTIDEPRESSANT DRUG MIRTAZAPINE



May 5, 2014

Mirtazapine (REMERON, REMERON SOLTAB) is a Food and Drug Administration (FDA)-approved drug to treat major depression.[1] In February 2014, Merck, the company that makes the brand-name version of the drug, issued the first warnings regarding reports of serious, life-threatening abnormal heart rhythms associated with its use. These initial warnings went to health care professionals in the U.K.[2],[3] Merck Canada and Health Canada (the Canadian version of the FDA) issued similar...

May 5, 2014

Mirtazapine (REMERON, REMERON SOLTAB) is a Food and Drug Administration (FDA)-approved drug to treat major depression.[1] In February 2014, Merck, the company that makes the brand-name version of the drug, issued the first warnings regarding reports of serious, life-threatening abnormal heart rhythms associated with its use. These initial warnings went to health care professionals in the U.K.[2],[3] Merck Canada and Health Canada (the Canadian version of the FDA) issued similar warnings to Canadian health care professionals the following month.[4]

The cases reported involved patients taking mirtazapine who had developed an abnormality in the electrical activity of the heart, called QT prolongation, which can be detected with a routine electrocardiogram test. QT prolongation alone is asymptomatic, but in some patients, it can lead to abnormal heart rhythms called torsade de pointes and ventricular tachycardia. Both can cause sudden death without prompt treatment.

Merck reported that some patients taking mirtazapine have developed torsades de pointes and that some have died. The company’s letter to health care professionals in Canada stated that most reported cases of these dangerous heart rhythm abnormalities have resulted from an overdose of the drug or have occurred in patients who have other risk factors for abnormal heart rhythms, including known cardiovascular disease, a family history of QT prolongation, or use of other drugs that can cause QT prolongation.[5],[6]

Thus far, the FDA has not issued any similar warnings in the U.S. Since 2007, the drug label for mirtazapine has included a section titled “Other Adverse Events Observed During Postmarketing Evaluation,” which mentions four cases of torsades de pointes in patients taking mirtazapine. However, the label dismisses a direct link to mirtazapine by stating that three of the four cases implicated other drugs the patients were taking.[7]

What you can do

Public Citizen’s Health Research Group has designated mirtazapine as a Limited Use drug (see https://www.worstpills.org/member/drugprofile.cfm?m_id=76).

If you are taking mirtazapine, it is important to tell your doctor if you have heart problems or any family history of heart problems. Tell your doctor if you feel dizzy or faint, have palpitations (a fluttering sensation in your chest), or develop seizures, as these can be symptoms of problems caused by abnormal heart rhythms.

Do not stop any medication without first talking to your physician.

Read the complete Canadian safety alert issued in March 2014:

http://www.healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2014/38711a-eng.php

Report any adverse effects related to mirtazapine to the FDA MedWatch program:

http://www.fda.gov/downloads/AboutFDA/ReportsManualsForms/Forms/UCM349464.pdf

References

[1] Food and Drug Administration. Remeron label. http://www.accessdata.fda.gov/drugsatfda_docs/label/2007/020415s019,021208s010lbl.pdf. Accessed May 5, 2014.

[2] MSD Ireland (Human Health) Limited. Zispin SolTab. http://www.medicines.ie/history/7468/SPC/Zispin++SolTab. Accessed May 5, 2014.

[3] EMC. Zispin SolTab. http://www.medicines.org.uk/emc/medicine/21573/SPC/#CLINICAL_PRECAUTIONS. Accessed May 5, 2014.

[4] Health Canada. Health Canada Endorsed Important Safety Information on REMERON / REMERON RD (mirtazapine). http://www.healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2014/38709a-eng.php. Accessed May 5, 2014.

[5] Health Canada. PUBLIC COMMUNICATION - Health Canada Endorsed Important Safety Information on REMERON / REMERON RD (mirtazapine). http://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2014/38711a-eng.php. Accessed May 5, 2014.

[6] Merck. Letter to health care professionals; Subject: Association of REMERON/REMERON RD (mirtazapine) with QT prolongation/Torsades de Pointes. March 28, 2014. http://www.merck.ca/Assets/News/REMERON%20DHCPL_EN_Final%20-%20signed.pdf. Accessed May 5, 2014.

[7] Food and Drug Administration. Remeron label. http://www.accessdata.fda.gov/drugsatfda_docs/label/2007/020415s019,021208s010lbl.pdf. (p.26). Accessed May 5, 2014.