Maximum Dose of Citalopram
The maximum recommended dose of citalopram is 40 mg per day for adults under 60 years of age, with a reduced maximum of 20 mg per day for adults over 60 years, patients with hepatic impairment, CYP2C19 poor metabolizers, or those taking CYP2C19 inhibitors. 1
Standard Adult Dosing
- The standard maximum dose of citalopram for adults under 60 years of age is 40 mg per day 2, 1
- Doses of 40 mg and 60 mg per day have shown significant improvement in depression symptoms compared to placebo, with no additional benefit observed at 60 mg compared to 40 mg 1
- Citalopram should be titrated gradually, typically starting at lower doses (e.g., 10-20 mg) and increasing as needed 2
Special Population Considerations
Elderly Patients (≥60 years)
- Maximum recommended dose is reduced to 20 mg per day for patients over 60 years of age due to increased risk of QT prolongation 1
- Pharmacokinetic studies show that citalopram AUC and half-life are increased in elderly subjects by 23-30% and 30-50%, respectively 1, 3
Hepatic Impairment
- Maximum recommended dose is 20 mg per day for patients with hepatic impairment 1
- Citalopram oral clearance is reduced by 37% and half-life is doubled in patients with reduced hepatic function 1
CYP2C19 Considerations
- Maximum recommended dose is 20 mg per day for CYP2C19 poor metabolizers 1
- Maximum recommended dose is 20 mg per day for patients taking concomitant CYP2C19 inhibitors (e.g., cimetidine, omeprazole) 1
- In CYP2C19 poor metabolizers, citalopram steady-state Cmax and AUC are increased by 68% and 107%, respectively 1
Safety Considerations
- The FDA issued a safety announcement in 2011 limiting citalopram dosage to 40 mg per day (20 mg for elderly) due to concerns about QT interval prolongation 4
- QT prolongation risk appears to be dose-dependent, with higher risk at doses exceeding the recommended maximum 4
- Despite concerns about QT prolongation, some research suggests the clinical significance of these findings may be questionable 4
- A retrospective study found that reducing citalopram doses from >40 mg to ≤40 mg was associated with increased hospitalizations without reduction in mortality or arrhythmia-related hospitalizations 5
Clinical Efficacy Considerations
- In clinical trials, citalopram at doses of 40 mg per day showed significant improvement in depression symptoms compared to placebo 1, 6
- While 60 mg per day was also effective in clinical trials, it did not demonstrate additional benefit over 40 mg per day 1, 6
- Lower doses (10-20 mg) also showed improvement compared to placebo but with less robust effects than higher doses 6
- Meta-analyses suggest that 20 mg appears to be the minimum effective dose for most patients, though some subgroups with severe depression may benefit from higher doses (up to 40 mg) 7
Practical Prescribing Guidance
- Titrate citalopram gradually, typically starting at 10-20 mg per day and increasing by increments of the initial dose every 5-7 days until therapeutic benefits or significant side effects become apparent 2
- After 9 months of treatment, consider dosage reduction to reassess the need for continued medication 2
- When discontinuing citalopram, taper over 10-14 days to limit withdrawal symptoms 2
- Monitor for common side effects including nausea, dry mouth, somnolence, insomnia, and increased sweating 6