eMedExpert Home > Medications Facts > Escitalopram (Lexapro)

Escitalopram was developed in a short time space of 3.5 years by the Danish pharmaceutical company Lundbeck. By comparison, it normally takes 5-6 years to develop a new drug. Lexapro (escitalopram oxalate) was developed by isolating a part of the citalopram HBr molecule, known as an isomer.

In the summer of 1997, H. Lundbeck A/S and Forest Laboratories, Inc. decided to develop escitalopram for the treatment of depression. Two years later, in August 1999, the first patients participated in the clinical studies which provide the clinical documentation for marketing authorisation. The pivotal clinical phase III studies were already completed in June 2000, and the first clinical results were publicly presented in December 2000 2.

In December 2001, Lundbeck received Swedish approval for the treatment of depression and panic disorder, and in January 2002, the product was approved in Switzerland for the treatment of depression. By May 2002 it had been approved in Belgium, Denmark, the UK, France, Iceland, Luxembourg, Norway and Austria, as a result of the European Mutual Recognition Procedure.

In the US, Forest submitted an NDA in March 2001 and in January 2002, Forest received an approvable letter from the FDA for escitalopram. By March 2002, Lundbeck had started to supply escitalopram to Forest 9. The FDA issued the approval of escitalopram for major depression in August 2002 and for generalized anxiety disorder in December 2003.

• Major Depressive Disorder
• Generalized Anxiety Disorder

• obsessive-compulsive disorder 11
• panic disorder 13
• social anxiety disorder 14
• posttraumatic stress disorder
• premenstrual dysphoric disorder 15
• pathological gambling 12
• menopause-related symptoms in women 16

• Advantages:
• high rates of remission 3
• fast onset of antidepressant effect, ususally within 2 weeks 5, 6
• significantly reduces relapse rates in depression and generalized anxiety disorder 7, 8
• well-tolerated (discontinuation rate <2% in clinical trials)
• low potential for clinically significant drug interactions
• superior to the SSRIs (citalopram, fluoxetine, paroxetine, sertraline) in efficacy (particularly in severe depression) 4, 10
• fewer discontinuation symptoms than with paroxetine and venlafaxine 8
• less severe weight gain and sexual problems
• Disadvantages:
• high costs
• as other SSRIs, may induce sexual dysfunction and weight gain

Escitalopram is the S-enantiomer of the racemate (citalopram). Pharmacological studies have shown that the R-enantiomer is not inert but counteracts the serotonin-enhancing properties of the S-enantiomer in citalopram.

The antidepressant action of escitalopram is presumably linked to the potentiation of serotonergic activity in the central nervous system resulting from its inhibitory effect on the reuptake of 5-HT from the synaptic cleft. Escitalopram is a highly selective serotonin reuptake inhibitor. Escitalopram has no, or minimal effect on noradrenaline, dopamine and gamma-amino butyric acid (GABA) uptake.

The elimination half-life of escitalopram is about 27-33 hours and is consistent with once-daily administration.

The pharmacokinetics of escitalopram are linear over the clinical dosage range. Steady state plasma levels are achieved within 7-10 days of administration.

Escitalopram tends to work faster than other SSRIs. In clinical studies, many patients treated with Lexapro began to feel better within 1 or 2 weeks 5, 6, although the full antidepressant effect may take 4 to 6 weeks.

After treatment with escitalopram, abrupt cessation of the drug may produce discontinuation (withdrawal) reactions. Onset of these symptoms usually occurs within a week of discontinuation or dose reduction and symptoms may last from a few days to 3 weeks. Escitalopram discontinuation symptoms include:

• dysphoric mood
• irritability
• fatigue
• weakness
• agitation
• dizziness
• sensory disturbances (paresthesias such as electric shock sensations)
• anxiety
• confusion
• headache
• lethargy
• emotional lability
• insomnia
• hypomania
• nausea and vomiting

Tips for Escitalopram withdrawal:

• Never stop your medication “cold turkey", withdrawal must be gradual to avoid withdrawal symptoms.
• Make each dose reduction as small as possible.
• Allow 1-2 weeks between each dosage reduction.
• If withdrawal symptoms are severe, increase the dosage slightly (e.g. to the dose at your last reduction). When symptoms have settled, resume withdrawal at a slower rate.

This tapering process may take up to several months, and should be done under doctor's supervision. With slow tapering withdrawal symptoms from antidepressants are usually absent, or if they occur, are mild and short-lived.

• Escitalopram (Lexapro) versus Other Medications

• 1. U.S. Food and Drug Administration. Escitalopram U.S. Prescribing Information.
• 2. H. Lundbeck A/S Annual report 2000. Available at: PDF Format
• 3. Bielski RJ, Ventura D, Chang CC. A double-blind comparison of escitalopram and venlafaxine extended release in the treatment of major depressive disorder. J Clin Psychiatry. 2004 Sep;65(9):1190-6. PubMed
• 4. Kennedy SH, Andersen HF, Lam RW. Efficacy of escitalopram in the treatment of major depressive disorder compared with conventional selective serotonin reuptake inhibitors and venlafaxine XR: a meta-analysis. J Psychiatry Neurosci. 2006 Mar;31(2):122-31. PubMedCentral
• 5. Gorman JM, Korotzer A, Su G. Efficacy comparison of escitalopram and citalopram in the treatment of major depressive disorder: pooled analysis of placebo-controlled trials. CNS Spectr. 2002 Apr;7(4 Suppl 1):40-4. PubMed
• 6. Wade A, Friis Andersen H. The onset of effect for escitalopram and its relevance for the clinical management of depression. Curr Med Res Opin. 2006 Nov;22(11):2101-10. PubMed
• 7. Rapaport MH, Bose A, Zheng H. Escitalopram continuation treatment prevents relapse of depressive episodes. J Clin Psychiatry. 2004 Jan;65(1):44-9. PubMed
• 8. Allgulander C, Florea I, Huusom AK. Prevention of relapse in generalized anxiety disorder by escitalopram treatment. Int J Neuropsychopharmacol. 2006 Oct;9(5):495-505. Epub 2005 Sep 6. PubMed
• 9. McRae AL. Escitalopram H Lundbeck. Curr Opin Investig Drugs 2002 Aug;3(8):1225-9
• 10. Baldwin DS, Cooper JA, Huusom AK, Hindmarch I. A double-blind, randomized, parallel-group, flexible-dose study to evaluate the tolerability, efficacy and effects of treatment discontinuation with escitalopram and paroxetine in patients with major depressive disorder. Int Clin Psychopharmacol. 2006 May;21(3):159-69. PubMed
• 11. Stein DJ, Andersen EW, Tonnoir B, Fineberg N. Escitalopram in obsessive-compulsive disorder: a randomized, placebo-controlled, paroxetine-referenced, fixed-dose, 24-week study. Curr Med Res Opin. 2007 Apr;23(4):701-11. PubMed
• 12. Grant JE, Potenza MN. Escitalopram treatment of pathological gambling with co-occurring anxiety: an open-label pilot study with double-blind discontinuation. Int Clin Psychopharmacol. 2006 Jul;21(4):203-9. PubMed
• 13. Stahl SM, Gergel I, Li D. Escitalopram in the treatment of panic disorder: a randomized, double-blind, placebo-controlled trial. J Clin Psychiatry. 2003 Nov;64(11):1322-7. PubMed
• 14. Kasper S, Stein DJ, Loft H, Nil R. Escitalopram in the treatment of social anxiety disorder: randomised, placebo-controlled, flexible-dosage study. Br J Psychiatry. 2005 Mar;186:222-6. PubMed
• 15. Freeman EW, Sondheimer SJ, Sammel MD, Ferdousi T, Lin H. A preliminary study of luteal phase versus symptom-onset dosing with escitalopram for premenstrual dysphoric disorder. J Clin Psychiatry. 2005 Jun;66(6):769-73. PubMed
• 16. Soares CN, Arsenio H, Joffe H, Bankier B, Cassano P, Petrillo LF, Cohen LS. Escitalopram versus ethinyl estradiol and norethindrone acetate for symptomatic peri- and postmenopausal women: impact on depression, vasomotor symptoms, sleep, and quality of life. Menopause. 2006 Sep-Oct;13(5):780-6. PubMed