Escitalopram (Lexapro)

Escitalopram in Brief
  • Generic name : Escitalopram oxalate
  • Brand names: Lexapro, Lexaprin, Cipralex, Sipralexa, Seroplex
  • Therapeutic class: Antidepressant
  • Pharmacologic class: Selective serotonin reuptake inhibitor (SSRI)
  • FDA Approved: August 14, 2002
  • Patent expiration date: March 14, 2012
  • Chemical Formula: C20H21N2FO
  • Pregnancy Category: C
  • Habit forming? No
  • Originally discovered: 1997, Denmark Denmark

Based on "Essential Psychopharmacology"
written by Stephen M. Stahl, MD, PhD


Escitalopram was developed in a short time space of 3.5 years by the Danish pharmaceutical company Lundbeck. By comparison, new drug development process normally takes 5-6 years. 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.

On March 14, 2012 Teva Pharmaceutical Industries/IVAX Pharmaceuticals gained U.S. FDA approval for the first generic Lexapro (escitalopram) tablets.

FDA approved indications

  • Major Depressive Disorder
  • Generalized Anxiety Disorder

In March 2009, the US FDA approved Lexapro for the acute and maintenance treatment of depression in adolescents between 12 and 17 years of age.

Off-label & Investigational uses

  • 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

Escitalopram "pros" and "cons"


  • 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 other SSRIs in severe depression 4, 10
  • fewer discontinuation symptoms than with paroxetine and venlafaxine 8
  • less severe weight gain and sexual problems


  • High costs despite generic availability
  • Causes sexual dysfunction17 and weight gain


Mechanism of action

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.

Time to clear out the system

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

Onset of action

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.

Escitalopram (Lexapro) withdrawal

After treatment with escitalopram, the abrupt cessation 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.

Further reading


  • 1. U.S. FDA Escitalopram Prescribing Information.
  • 2. H. Lundbeck A/S Annual report 2000.
  • 3. Bielski RJ, Ventura D, Chang CC. 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. PubMed
  • 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. 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. Townsend MH, Conrad EJ. The therapeutic potential of escitalopram in the treatment of panic disorder. Neuropsychiatr Dis Treat. 2007 Dec;3(6):835-8. Full text
  • 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.
  • 15. Eriksson E, Ekman A, Sinclair S, Sörvik K, Ysander C, Mattson UB, Nissbrandt H. Escitalopram in premenstrual dysphoric disorder during luteal phase. J Clin Psychopharmacol. 2008 Apr;28(2):195-202. 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
  • 17. Kassan M, Lasker GF, Sikka SC, Mandava SH, Gokce A, Matrougui K, Hellstrom WJ, Kadowitz PJ, Serefoglu EC. Chronic escitalopram treatment induces erectile dysfunction by decreasing nitric oxide bioavailability mediated by increased nicotinamide adenine dinucleotide phosphate oxidase activity and reactive oxygen species production. Urology. 2013 Nov;82(5):1188.e1-7. PubMed

Published: March 31, 2008
Last updated: February 01, 2017

Interesting facts

Escitalopram facts
  • Escitalopram is the newest and most selective of the selective serotonin reuptake inhibitors.

More Facts
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