Lexapro -- the brand name for escitalopram -- and Celexa -- the brand name for citalopram -- are very similar in many ways. They are both prescription drugs used for depression and both belong to a class of medications called selective serotonin reuptake inhibitors (SSRIs). As SSRIs, their mood-elevating effects are primarily the result of increased levels of serotonin in the brain.
But Lexapro and Celexa are not interchangeable. They differ in chemical structure, uses, effectiveness and some side effects. Your doctor will help you decide which is best for you.
Celexa is a mixture of 2 similar, but not identical, types of citalopram molecules called enantiomers. Enantiomers are molecules that contain the same number and types of atoms, but the atoms are arranged differently so the enantiomers -- like your right and left hands -- are mirror images of each other. The enantiomers in Celexa are called R-citalopram and S-citalopram.
Lexapro was developed from Celexa. It contains just the S-citalopram enantiomer, which is the reason for its generic name _es_citalopram. Lexapro was developed because researchers discovered that S-citalopram was a more effective antidepressant than R-citalopram.
Both Lexapro and Celexa are approved by the U.S. Food and Drug Administration (FDA) for the treatment of major depressive disorder. Lexapro is also approved for generalized anxiety disorder, whereas Celexa is only approved for depression. This doesn't necessarily mean that Celexa cannot help with anxiety -- it simply means that Celexa has not undergone formal assessment by the FDA to ensure that its benefits outweigh its risks when used to treat anxiety.
Even though the usual dose of Lexapro is about one-half of the usual dose for Celexa, Lexapro is generally more effective than Celexa for treating major depression. A systematic review of several previous studies published by the Norwegian Institute of Public Health in 2007 reported that depression was more likely to improve with Lexapro than with Celexa. A more recent systematic review published in the “Cochrane Database of Systematic Reviews” in July 2012 also compared Lexapro and Celexa for the treatment of major depressive disorder. The results showed that improvement was about 1.5 times more likely with Lexapro than with Celexa.
For both Lexapro and Celexa, FDA-approved prescribing information contains similar warnings about possible serious side effects, including suicidal thoughts or behavior, serotonin syndrome, withdrawal symptoms when abruptly stopping the drug, acute glaucoma, abnormal bleeding, low sodium levels, seizures and impaired ability to concentrate, think or perform physical tasks. Less serious, and more frequent, side effects are also generally similar for the 2 drugs.
One difference between Lexapro and Celexa is a side effect related to the heart. In 2012, the FDA issued a warning that Celexa may cause a heart problem known as prolonged QT interval, which may lead to serious heart rhythm abnormalities. Because of this, the FDA lowered the maximum recommended dose of Celexa and indicated that the drug should not be used by people with conditions that predispose to a prolonged QT interval. Lexapro can also prolong the QT interval, but the amount of prolongation is only about one-half that produced by Celexa. The FDA has not recommended that the maximum dose of Lexapro be decreased or that it be avoided in people with predisposing conditions.
Fatigue is the other reported difference between Lexapro and Celexa. The July 2012 “Cochrane Database of Systematic Reviews” review found that fatigue was only about one-third as likely with Celexa than with Lexapro. The authors detected no other differences in side effects between the 2 drugs, but they did not evaluate QT prolongation or heart rhythm disturbances.
Reviewed and revised by Mary D. Daley, M.D.