Citalopram (Celexa)

Primer

Citalopram (Trade name: Celexa) is an antidepressant in the selective serotonin reuptake inhibitor (SSRI) class commonly used in the treatment of major depressive disorder.

Pharmacokinetics

Pharmacokinetics of Citalopram

Absorption
Distribution
Metabolism
Elimination
Half-life

Citalopram: Cytochrome P450 Metabolism

Substrate of (Metabolized by)
Induces
Inhibits

Pharmacodynamics

Mechanism of Action

Toxicity

Indications

  • Major depressive disorder
  • Generalized anxiety disorder
  • Behavioural and psychological symptoms of dementia

Citalopram vs. Escitalopram

Recommended daily dose ranges for citalopram and escitalopram

Population Citalopram Escitalopram
Adult 18-65 years
without risk factors 		• Starting: 20mg
• Maximum: 40mg 		• Starting: 10mg
• Maximum: 20mg
Adult >65 years or
impaired hepatic
function 		• Starting: 10mg
• Maximum: 20mg 		• Starting: 5mg
• Maximum: 10mg
Taking omeprazole* • Starting: 20mg
• Maximum: 20mg 		• Starting: 5mg
• Maximum: 10mg
*Omeprazole increases plasma levels of citalopram and escitalopram, increasing the risk of QT prolongation and hyponatraemia.

Dosing

Dosing for Citalopram

Starting 10 mg PO daily for 2 weeks
Titration Increase by 10 mg every 1 to 2 weeks depending on tolerability
Maximum 40 mg (previously approved for up to 60 mg/day, but no longer due to QTc concerns)
Taper Tapering/Switching Antidepressants

Formulations

  • Citalopram comes in oral formulation.

Monitoring

Contraindications

Absolute

Relative

Drug-Drug Interactions

  • Altered anticoagulant effects, including increased bleeding, have been reported when SSRIs and SNRIs are co-administered with warfarin. Thus, patients on warfarin therapy should be carefully monitored when citalopram is initiated or discontinued.[1]

Side Effects

Adverse Events

QTc Prolongation

Citalopram is linked to QTc prolongation. It is thought that SERT-R is the cause of QTc prolongation in dose dependent fashion

Clinical Pearls

  • The “cleanest” and most selective of the SSRIs, with minimal affinity for muscarinic, dopaminergic or norepinephrine receptors
  • Antihistamine effects likely contributes to more sedation, weight gain
  • May need HS dosing if too sedating

Special Populations

Geriatric

Pediatric

Obstetric and Fetal

Medically Ill

Resources

References

1) Product Monograph RIVA-CITALOPRAM