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Citalopram



Citalopram
Systematic (IUPAC) name
1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-
1,3-dihydro[2]benzofuran-5-carbonitrile
Identifiers
CAS number 59729-33-8
ATC code N06AB04 N06AB10
PubChem 2771
DrugBank APRD00147
Chemical data
Formula C20H21FN2O 
Mol. mass 324.392 g/mol
Pharmacokinetic data
Bioavailability 80%
Metabolism hepatic (CYP3A4 & CYP2C19)
Half life 35 hours
Excretion Mostly as unmetabolized Citalopram, partly DCT and traces of DDCT in urine
Therapeutic considerations
Pregnancy cat.

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Legal status

Prescription only

Routes Oral

Citalopram is an antidepressant drug used to treat depression associated with mood disorders. It is also used on occasion in the treatment of body dysmorphic disorder and anxiety.

Citalopram belongs to a class of drugs known as selective serotonin reuptake inhibitors (SSRIs). It is sold under the brand-names Celexa (U.S., Forest Laboratories, Inc.), Cipramil , Citrol, Seropram,Talam (Europe and Australia), Recital (Israel, Thrima Inc. for Unipharm Ltd.), Zetalo (India), Celepram, Ciazil (Australia), Zentius (South America, Roemmers), Cilift (South Africa) and Cipram (Denmark, H. Lundbeck A/S).

Contents

History

Citalopram was originally created in 1989,[1] by the pharmaceutical company Lundbeck. The patent expired in 2003, allowing other companies legally to produce generic versions.

Lundbeck has recently released an updated formulation called escitalopram (also known as Cipralex or Lexapro), which is the S-enantiomer of the racemic citalopram (see below), and acquired a new patent for it. In the United States, Forest Laboratories licenses the rights for both Celexa and Lexapro from Lundbeck, which is based in Denmark.

Indications

Approved

Citalopram is primarily used to treat the symptoms of depression but can also be prescribed for social anxiety disorder, panic disorder or obsessive-compulsive disorder. Also prescribed in Huntington's disease and premenstrual dysphoric disorder.

Unapproved/Off-label/Investigational

Citalopram has been found to significantly reduce the symptoms of diabetic neuropathy,[2] and premature ejaculation.[3] There is also evidence that citalopram may be effective in the treatment of post-stroke pathological crying.[4]

While on its own Citalopram is less effective than amitriptyline in the prevention of migraines, in refractory cases combination therapy may be more effective.[5]


Side effects and drug interactions

Citalopram is generally considered safe and well-tolerated in the therapeutic dose range of 20 to 60 mg/day. A doctor must always monitor a patient taking an SSRI like citalopram. Distinct from some other agents in its class, citalopram exhibits linear pharmacokinetics and minimal drug interaction potential, making it a better choice for the elderly or comorbid patients.[6] Citalopram should be taken with caution when using St John's wort.[7]

Citalopram can have a number of adverse effects. In clinical trials, over 10% of patients reported one or more of the following side effects: fatigue, drowsiness, dry mouth, increased sweating (hyperhidrosis), trembling, headache, dizziness, sleep disturbances, insomnia, cardiac arrhythmia, blood pressure changes, nausea and/or vomiting, diarrhea, heightened anorgasmia in females, impotence and ejaculatory problems in males. In rare cases (around over 1% of cases), some allergic reactions, convulsions, mood changes, anxiety and confusion have been reported. Also sedation may be present during treatment of citalopram. If this occurs it is advisable to take the dose at bedtime instead of in the morning.

Another uncommon side effect is bruxism (teeth grinding).[8] When patients start using citalopram they may experience a feeling similar to electricity or minor shocks in their upper body and in their hands. This is caused by the chemical changes occurring in the brain and they pass with time. Occasionally, panic attacks, thoughts of suicide or self-injury may occur or increase in the first few weeks, before the antidepressant effect starts.[9]

Citalopram and other SSRIs have been shown to cause sexual side effects in some patients, both males and females.[10] Although usually reversible, these sexual side effects can sometimes last for months, years or possibly indefinitely even after the drug has been completely withdrawn. This disorder is known as Post SSRI Sexual Dysfunction.

Citalopram is contraindicated in individuals taking MAOIs. It is considered relatively safe in overdose, although fatal cases of dosages 840 mg to 1960 mg have been reported.[11]

SSRI discontinuation syndrome has been reported when treatment is stopped. Tapering off citalopram therapy, as opposed to abrupt discontinuation, is recommended in order to diminish the occurrence of discontinuation symptoms.

Stereochemistry

Citalopram has a stereocenter, to which a 4-fluorophenyl group and an N,N-dimethyl-3-aminopropyl group bind. Due to this chirality the molecule exists in (two) enantiomeric forms (mirror images). They are termed S-(+)-citalopram and R-(−)-citalopram.

S-(+)-citalopram R-(−)-citalopram

Citalopram is sold as a racemic mixture, consisting of 50% R-(−)-citalopram and 50% S-(+)-citalopram. Only the S-(+) enantiomer has the desired antidepressant effect. Lundbeck now markets the S-(+) enantiomer, the generic name of which is escitalopram. Whereas citalopram is supplied as the hydrobromide, escitalopram is sold as the oxalate salt (hydrooxalate).[12] In both cases, the salt forms of the amine makes these otherwise lipophilic compounds water-soluble.

References

  1. ^ Dorell K, Cohen MA, Huprikar SS, Gorman JM, Jones M (2005). "Citalopram-induced diplopia". Psychosomatics 46 (1): 91–3. PMID 15765832.
  2. ^ Sindrup SH, Bjerre U, Dejgaard A, Brøsen K, Aaes-Jørgensen T, Gram LF (1992). "The selective serotonin reuptake inhibitor citalopram relieves the symptoms of diabetic neuropathy". Clin. Pharmacol. Ther. 52 (5): 547–52. PMID 1424428.
  3. ^ Atmaca M, Kuloglu M, Tezcan E, Semercioz A (2002). "The efficacy of citalopram in the treatment of premature ejaculation: a placebo-controlled study". Int. J. Impot. Res. 14 (6): 502–5. doi:10.1038/sj.ijir.3900918. PMID 12494286.
  4. ^ Andersen G, Vestergaard K, Riis JO (1993). "Citalopram for post-stroke pathological crying". Lancet 342 (8875): 837–9. PMID 8104273.
  5. ^ Rampello L, Alvano A, Chiechio S, et al (2004). "Evaluation of the prophylactic efficacy of amitriptyline and citalopram, alone or in combination, in patients with comorbidity of depression, migraine, and tension-type headache". Neuropsychobiology 50 (4): 322–8. doi:10.1159/000080960. PMID 15539864.
  6. ^ Keller MB (2000). "Citalopram therapy for depression: a review of 10 years of European experience and data from U.S. clinical trials". The Journal of clinical psychiatry 61 (12): 896–908. PMID 11206593.
  7. ^ Karch, Amy (2006). 2006 Lippincott's Nursing Drug Guide. Philadephia, Baltimore, New York, London, Buenos Aires, Hong Kong, Sydney, Tokyo: Lippincott Williams & Wilkins. ISBN 1-58255-436-6. 
  8. ^ Bruxism/Teeth grinding. Mayo Clinic (2007-05-18). Retrieved on 2007-07-25.
  9. ^ Citalopram Hydrobromide Brand name: Celexa Drug monograph; Contraindications. Internet Mental Health (August 1999). Retrieved on 2007-07-25.
  10. ^ Clayton A, Keller A, McGarvey EL (2006). "Burden of phase-specific sexual dysfunction with SSRIs". Journal of affective disorders 91 (1): 27–32. doi:10.1016/j.jad.2005.12.007. PMID 16430968.
  11. ^ Citalopram Hydrobromide Brand name: Celexa Drug monograph; Symptoms and Treatment of Overdosage. Internet Mental Health (August 1999). Retrieved on 2007-07-25.]
  12. ^ Celexa.com

Lunbeck's official websites for citalopram under the trade name Cipramil:

  • Cipramil.com

Forest's official websites for citalopram under the trade name Celexa:

  • Celexa.com
  • Celexa product page on Forest Laboratories web site
  • Cipramil Patient Information Leaflet Cipramil Patient Information Leaflet
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Citalopram". A list of authors is available in Wikipedia.
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