Citolapram, marketed under the brand name Celexa, belongs to a group of anti-depressants called SSRIs — selective serotonin reuptake inhibitors. The brain chemical serotonin seems to be decreased in people suffering from depression. The SSRIs do what their name implies; they slow the removal of this chemical from the blood. This allows the available serotonin to be active longer, decreasing symptoms of depression. These SSRIs provide relief to millions of people suffering from depression, but like all medications, have side effects or potential complications associated with their use. Celexa is no exception.
Recently, however, the Food and Drug Administration issued a specific warning regarding Celexa and its potential association with certain abnormal heart rhythms. The FDA, in its August 2011 warning, cautions against using more than 40mg per day of Celexa in any patient due to the risk of these arrhythmias.
The ventricles are the pumping chambers of the heart and receive their electrical signal from the atria, the collecting chambers, as the impulse travels through the heart muscle. This allows a coordinated and effective heartbeat. When this conduction sequence is disrupted, arrhythmias occur, leading to ineffective pumping of blood and, as a result, inadequate delivery of oxygen to the body. With higher doses of Celexa, arrhythmias related to the uncoordinated contraction of the ventricles presents a danger, especially as related to QT prolongation.
The QT segment on the electrocardiogram –ECG– is an interval that can be measured. It is the time it takes the heart to beat and then recover and be able to receive another electrical signal to be able to beat again. Celexa leads to prolongation of this interval, which allows errant signals to cause irregular heartbeats. This may progress to a very fast, ineffective beating of the ventricles, called ventricular tachycardia or a particular subtype of ventricular arrhythmia called “Torsades de Pointes.” These can be serious or even fatal.
Caution with Celexa use is especially advised in patients with pre-existing heart conditions and those with low levels of potassium and magnesium in their blood. A pre-existing prolonged QT puts a patient at particular risk. Some people have this disorder from birth, and sometimes it can be a result of medications or other disease processes. An ECG can show the presence or absence of this condition and the FDA now advises that Celexa not be used at all in people with congenital prolonged QT syndrome and certain other heart conditions.
For people without pre-existing conditions, the risk seems to be dose-related and, therefore, it is not always necessary to stop taking Celexa. The dose should be kept to less than 40mg per day. For those who do need to decrease or stop this medication, it is crucial to do this only with the guidance of a physician. Serious problems can occur by decreasing or stopping SSRIs suddenly. It is unclear at this time exactly how many people who use Celexa also fall into the higher-risk categories. People taking this medication should seek the advice of the prescribing physician as soon as possible.