citalopram

General information

• Class: Adjunctive therapy
• Common US brands: Celexa
• Typical dose range: Typical start is 20 mg once daily; increase to 40 mg/day after ≥4 weeks if needed (limit to 20 mg/day for ≥60 years, hepatic impairment, CYP2C19 inhibitors).
• Therapeutic drug monitoring not routinely recommended.
• Last reviewed: 2025-12-29

Dosing & forms

• Forms/strengths: Tablets 10–40 mg; oral solution 10 mg/5 mL.
• Frequency: Typical start is 20 mg once daily; increase to 40 mg/day after ≥4 weeks if needed (limit to 20 mg/day for ≥60 years, hepatic impairment, CYP2C19 inhibitors).
• Typical range: Typical start is 20 mg once daily; increase to 40 mg/day after ≥4 weeks if needed (limit to 20 mg/day for ≥60 years, hepatic impairment, CYP2C19 inhibitors).

Mechanism (brief)

Selective serotonin reuptake inhibitor (SSRI).

Metabolism & Half‑life

• Metabolism: CYP2C19, CYP3A4, CYP2D6
• Half‑life: Single-dose mean 35 h; Steady-state mean 38 h

Therapeutic Drug Monitoring (TDM)

Recommended: No

Monitoring highlights

• QTc monitoring when cardiac risk is present or when combining multiple QT-active medications; recheck ECG after dose changes when indicated.
• Sodium in older adults or patients on diuretics if symptoms suggest hyponatremia.
• Bleeding/bruising risk when combined with NSAIDs, antiplatelets, or anticoagulants; reinforce early symptom reporting.
• Mood elevation or agitation in bipolar-spectrum illness; coordinate prevention plans via the bipolar disorder hub.

Sources

• Citalopram prescribing information — DailyMed (2025)
• APA Clinical Practice Guideline for the Treatment of Depression — American Psychiatric Association (2023)
• CANMAT 2024 Clinical Guidelines for Major Depressive Disorder — Canadian Journal of Psychiatry (2024)
• Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder — The Lancet (2018)