Celexa at Higher Doses Linked to Abnormal Heart Rhythm in Certain Patients
The US Food and Drug Administration (FDA) has issued a warning to physicians and patients that the antidepressant drug citalopram (brand name Celexa) has been linked to a dangerous heart rhythm change and should not be used in doses higher than 40 milligrams per day.
Celexa Greater than 40 Milligrams Confers No Benefit and Linked to Significant Risks
Citalopram belongs to a class of medications known as serotonin reuptake inhibitors, or SSRIs. It works by increasing the amount of serotonin, a natural substance in the brain that helps maintain mental balance. Celexa comes in 10, 20 and 40 milligram tablets, but some physicians have prescribed 60 milligram doses for resistant depression based on information on the drug label. Studies, however, indicate that citalopram does not show depression symptom benefits in doses higher than 40 mg.
The FDA states that doses higher than 40 milligrams have been linked to prolonged QT interval. Long QT Syndrome (LQTS) is a heart rhythm disorder that can potentially cause fast, chaotic heartbeats that could trigger a sudden fainting spell or seizure. In some cases, the heart beats so erratically for so long that it can cause sudden death.
The findings are based on a post-marketing study of 119 adults taking Celexa or a placebo. At 20 milligrams, the drug produced mean QT prolongation of 8.5 msec. At 60 mg, QT intervals were extended by an average of 18.5 msec. The FDA extrapolated from this data that a 40 mg dose would likely prolong QT intervals by an average of 12.6 msec, which was deemed marginally acceptable.
Patients at particular risk for developing the condition include those with a genetic mutation that puts them at risk for LQTS. The drug should also be avoided in those with congestive heart failure, bradyarrhythmias, or a predisposition to hypokalemia (low blood potassium) or hypomagnesemia (low blood magnesium) because of concomitant illness or drugs, warns the FDA.
For those taking Celexa, the FDA also warns not to stop taking the drug or change the dose without first speaking to your healthcare provider. Suddenly stopping citalopram can cause unwanted side effects. Patients should also seek immediate care if they experience an irregular heartbeat, shortness of breath, dizziness or fainting while taking Celexa.
Patients who have experienced adverse effects related to Celexa, or any medication, should contact the FDA MedWatch program by telephone at 1-800-332-1088, by fax at 1-800-332-1078, or mail at 5600 Fishers Lane, Rockville MD 29857. Consumers can also report medication concerns online at www.fda.gov.
Physicians are urged to perform blood work on patients before prescribing Celexa and correct hypokalemia and hypomagnesemia before administering. Electrolytes should be monitored as clinically indicated. Healthcare professionals may also want to consider more frequent electrocardiogram (ECG) monitoring in patients at risk for LQTS.
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