What is the recommended dosage and treatment protocol for Citalopram (Selective Serotonin Reuptake Inhibitor) for depression?

Citalopram Dosing and Treatment Protocol for Depression

For adults with major depressive disorder, initiate citalopram at 20 mg once daily and increase to a maximum of 40 mg/day after at least one week if needed, with doses above 40 mg/day not recommended due to QT prolongation risk. 1

Initial Dosing Strategy

• Start at 20 mg once daily (morning or evening, with or without food) for most adult patients 1
• Allow a minimum of one week before any dose increase to assess tolerability and initial response 1
• The 40 mg/day and 60 mg/day doses demonstrate significantly greater efficacy than placebo on all depression rating scales, while 10 mg/day and 20 mg/day show more modest effects 2

Maximum Dosing and Safety Limits

The absolute maximum dose is 40 mg/day for most patients due to QT prolongation risk, with no demonstrated additional benefit at 60 mg/day compared to 40 mg/day 1, 2

Reduced Maximum Doses (20 mg/day) Required For:

• Patients over 60 years of age 1
• Hepatic impairment 1
• CYP2C19 poor metabolizers 1
• Concurrent use of cimetidine or other CYP2C19 inhibitors 1

Treatment Duration and Maintenance

• Acute phase: Continue at effective dose for 6-8 weeks to achieve response 1
• Continuation phase: Maintain treatment for several months after acute response to prevent relapse 1
• Maintenance therapy: Long-term treatment (up to 24 weeks following initial response) significantly reduces relapse rates compared to placebo 1
• The dose that induced remission should generally be continued during maintenance treatment 1

Therapeutic Drug Monitoring

• Therapeutic plasma range: 30-130 ng/mL for citalopram 3
• At 40 mg/day, expected steady-state levels are approximately 86±38 ng/mL for parent compound and 35±11 ng/mL for demethylcitalopram 3

Discontinuation Protocol

Never stop citalopram abruptly - gradual dose reduction over 10-14 days is essential to minimize withdrawal symptoms 3

• If intolerable symptoms emerge during taper, resume the previous dose and decrease more gradually 1
• Monitor for discontinuation symptoms including dizziness, sensory disturbances, anxiety, and flu-like symptoms 1

MAOI Interactions

Critical safety requirement: Allow at least 14 days between discontinuing an MAOI and starting citalopram, and vice versa 1

Special Clinical Scenarios

Adolescent Depression (Ages 12-18)

• Starting dose: 10 mg once daily 3
• Effective dose: 20 mg daily 3
• Maximum dose: 60 mg daily (though lower than adult maximum due to different safety profile in this population) 3
• Increments of 10 mg 3

Treatment-Resistant Depression

• If inadequate response at 40 mg/day after 4-8 weeks, consider augmentation strategies (such as lithium) rather than exceeding maximum dose 4
• Switching to another SSRI may be appropriate if tolerability issues emerge, as SSRIs do not have interchangeable tolerability profiles 5

Renal Impairment

• Mild to moderate: No adjustment needed 1
• Severe: Use with caution (specific dosing not established) 1

Monitoring Requirements

Initial Phase (First 4-8 Weeks)

• Contact patient within first week after initiation to assess tolerability and adherence 3
• Monitor for behavioral activation, switch to mania, or suicide-related events, particularly in adolescents and young adults 3
• Avoid starting at higher than recommended doses, as this increases risk of deliberate self-harm and suicidal behavior 3

Ongoing Monitoring

• Assess response using standardized depression rating scales (HAM-D, MADRS, CGI) 2
• Monitor for common adverse effects: nausea, dry mouth, somnolence, insomnia, increased sweating 2
• ECG monitoring may be warranted in patients at risk for QT prolongation 1

Common Pitfalls to Avoid

• Do not exceed 40 mg/day in standard patients - no additional efficacy and increased cardiac risk 1, 2
• Do not use 20 mg/day maximum doses in elderly, hepatically impaired, or CYP2C19-related scenarios - this is a hard ceiling, not a starting point 1
• Do not rush dose escalation - allow full week intervals between increases 1
• Do not abruptly discontinue - always taper gradually 3, 1
• Do not combine with MAOIs without appropriate washout period 1

Efficacy Timeline

• Initial improvement may be seen within 2 weeks 5
• Full therapeutic trial requires 4-8 weeks at adequate dose 3
• Maximum benefit typically achieved by 6 weeks 2