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Citalopram

Celexa

FDA ApprovedPsychotherapeuticsSSRI Antidepressants
Half-life: Approximately 35 hoursPregnancy: Category C

Overview

Citalopram is a selective serotonin reuptake inhibitor (SSRI) antidepressant used to treat major depressive disorder.

Indications

  • Major depressive disorder

Contraindications

  • Concurrent or recent use of monoamine oxidase inhibitors
  • Congenital long QT syndrome
  • Concurrent use of pimozide

Classification

PsychotherapeuticsSSRI AntidepressantsCentral Nervous System

Mechanism of Action

Selectively inhibits the reuptake of serotonin at the presynaptic neuronal membrane, increasing serotonergic neurotransmission with minimal effect on other neurotransmitters.

Pharmacodynamics

Improves mood over several weeks of treatment. Citalopram is highly selective for the serotonin transporter and has a dose-dependent effect on the QT interval.

Pharmacokinetics

Absorption
Well absorbed orally, unaffected by food.
Distribution
Widely distributed with moderate protein binding.
Metabolism
Metabolized in the liver mainly by CYP2C19 and CYP3A4 to less active metabolites.
Excretion
Excreted in urine and feces as parent drug and metabolites.
Half-life
Approximately 35 hours
Bioavailability
Approximately 80%
Protein Binding
Approximately 80%

Dosage

Typical dosage: 20 mg once daily, up to 40 mg; maximum 20 mg in patients over 60 or with hepatic impairment

Available Forms

  • Tablet
  • Oral solution

Side Effects

Common

  • Nausea
  • Dry mouth
  • Somnolence
  • Insomnia
  • Sexual dysfunction

Serious

  • QT prolongation
  • Serotonin syndrome
  • Hyponatremia

Rare

  • Seizures

Drug Interactions

Tramadolmajor

Additive serotonergic effects increase the risk of serotonin syndrome.

Ondansetronmajor

Combined QT-prolonging effects increase the risk of torsades de pointes.

Warnings

⚠️BLACK BOX WARNING

Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies. Monitor patients closely for clinical worsening and emergence of suicidal thoughts, especially when initiating or changing the dose.

Pregnancy

Category C

Toxicity

Overdose can cause QT prolongation, seizures, and serotonin syndrome.

Overdose

Provide supportive care with cardiac monitoring; treat seizures with benzodiazepines. There is no specific antidote.

References

Looking for patient-friendly information? Visit RemedyDoor for easy-to-read guides about this medication.