Celexa, generic name citalopram, is approved by the FDA for treatment of major depressive disorder, although like most of the selective serotonin reuptake inhibitors (SSRI) Celexa is often used off-label for the treatment of anxiety, obsessive compulsive disorder, and panic disorder. IN recent years Celexa has been found to be associated with cardiac arrhythmias in higher doses and the maximum FDA approved Celexa dosage has been reduced to 40 mg daily in most patients, although the maximum Celexa dosage in patients over the age of 60 or with a known poor CYP-2D19 metabolism. Prior to the reduction in maximum Celexa dosage was 80 mg daily.
The usual starting Celexa dosage in adults with depression is 20 mg daily, most often used as a single daily morning dose. One of the potential Celexa side effects is trouble sleeping, and this is felt to be less common if the Celexa dosage is taken early in the day. In patients with anxiety often the starting Celexa dosage is 10 mg daily, which is then increased to 20 mg daily after 2-4 weeks if needed. After initiation of the usual Celexa dosage of 20 mg daily most patients will notice the earliest improvement between one and four weeks after the onset of treatment, and may continue to notice improvement for 8-12 weeks. Many physicians will consider a Celexa dosage increase after 4 weeks on the initial Celexa dosage if a patient has noted only slight improvement, but may wait longer if a moderate to good response has been noted.
Celexa has not been approved for use in children, and like all SSRIs carries a black-box warning for use in patients under age 25 years old. In younger patients the risk of suicide may be increased with Celexa, and careful observation is advised when Celexa is used in patients in this age range. Increased suicidality is not observed in patients age 25 and older, and may even be decreased in patients over age 65.
Common Celexa side effects include sexual dysfunction. In women difficulty achieving orgasm is often noted, and in men delayed ejaculation or even inability to ejaculate may be noted. Serious Celexa side effects worsening depression, the serotonin withdrawal syndrome (more below on this topic), hyponatremia, mania (especially in patients with bipolar disorder), extrapyramidal symptoms, and especially at higher Celexa dosage Torsades de Pointes. This serious cardiac arrhythmia that can be fatal is the reason the maximum Celexa dosage was reduced to 40 mg daily.
Like all SSRI medications when discontinuing Celexa it is recommended that the Celexa dosage be gradually tapered rather than abruptly stopped. Abrupt cessation of Celexa from a moderate or high Celexa dosage may result in a discontinuation syndrome. Symptoms of Celexa discontinuation vary from none at all in some patients, to minor balance issues, zinging or zapping sensations sometimes called brain-zaps, and can be very disconcerting to patients with more severe symptoms. The SSRI discontinuation syndrome is well recognized and varies a good deal from one patient to another. The incidence and severity of the SSRI discontinuation syndrome also varies from one medication in the SSRI class to another. In general the shorter the serum half-life of the SSRI the more frequent and more severe the SSRI discontinuation symptoms. Celexa has a serum half-life of approximately 35 hours which is longer than many of the other SSRI medications, and so the incidence and severity of discontinuation symptoms is less than with many other drugs in the class. For comparison Paxil (paroxetine) has a serum half-life of 21 hours, Zoloft (sertraline) has a half-life of 26 hours, Effexor (venlafaxine, an SNRI) has a half-life of 11 hours, and Prozac (fluoxetine) is extraordinary with its half-life of 4-6 days. This very long fluoxetine half-life allows weekly dosing of Prozac in some patients, and sometimes Prozac is used to alleviate SSRI discontinuation symptoms in patients with severe difficulty getting off another SSRI.
In summary Celexa dosage typically ranges from 10 mg to 40 mg daily except in patients with delayed Celexa metabolism such as persons over age 60 or with known slow CYP-2D19 metabolism in whom the maximum approved Celexa dosage is 20 mg daily. Celexa is usually taken as a single morning dose daily.