Citalopram (Celexa)

Pharmacokinetics of Citalopram

Citalopram: Cytochrome P450 Metabolism

Substrate of (Metabolized by)
  • Major depressive disorder
  • Generalized anxiety disorder
  • Behavioural and psychological symptoms of dementia

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
• Starting: 10mg
• Maximum: 20mg
• Starting: 5mg
• Maximum: 10mg
Taking omeprazole* • Starting: 20mg
• Maximum: 20mg
• Starting: 5mg
• Maximum: 10mg

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
  • Citalopram comes in oral formulation.
  • 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]

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

  • 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