Skip to main content
Resources › Psychotropics A-Z › Citalopram | Celexa | Celexa
Selective Serotonin Reuptake Inhibitor (SSRI)

Citalopram | Celexa

Clinical Overview

Citalopram is a selective serotonin reuptake inhibitor (SSRI) indicated for major depressive disorder. It has high selectivity for the serotonin transporter with minimal effects on other neurotransmitter systems, but requires dose limitations due to QT prolongation risk at higher doses.

Primary Clinical Applications

Citalopram is indicated for major depressive disorder in adults. It was one of the most widely prescribed antidepressants due to its efficacy and tolerability, though dose restrictions implemented in 2011 have limited its use compared to other SSRIs with fewer cardiac concerns.

Mechanism and Pharmacological Profile

Citalopram selectively inhibits serotonin reuptake with high specificity and minimal activity at other receptors. However, it blocks cardiac potassium channels in a dose-dependent manner, leading to QT interval prolongation and FDA-mandated maximum dose restrictions.

Clinical Considerations

The FDA has established maximum dose limits: 40 mg daily for most adults, and 20 mg daily for patients over 60 years, those with hepatic impairment, or CYP2C19 poor metabolizers. These restrictions have made other SSRIs more favorable choices for patients requiring higher doses.

Prescribing Information

Dosing & Administration

Major Depressive Disorder – Adults:

  • Initial: 20 mg once daily
  • Range: 20-40 mg daily
  • Maximum: 40 mg daily (general population)

Dose Restrictions:

  • Patients >60 years: Maximum 20 mg daily
  • Hepatic impairment: Maximum 20 mg daily
  • CYP2C19 poor metabolizers: Maximum 20 mg daily

Administration:

  • Take once daily, morning or evening
  • With or without food
  • Same time each day for consistency

Indications

  • Treatment of major depressive disorder in adults

Contraindications

  • Hypersensitivity to citalopram
  • Use with MAOIs (within 14 days)
  • Use with pimozide
  • Congenital long QT syndrome
  • Use with linezolid or IV methylene blue

Warnings & Precautions

  • Boxed Warning: Increased risk of suicidal thoughts and behavior in patients under 25 years
  • QT prolongation: Dose-dependent risk – maximum dose restrictions apply
  • Serotonin syndrome: Risk with concurrent serotonergic drugs
  • Activation of mania: Monitor in patients with bipolar disorder
  • Discontinuation syndrome: Taper gradually when stopping
  • Hyponatremia: Particularly in elderly patients

Drug Interactions

  • MAOIs: Contraindicated – minimum 14-day washout
  • Pimozide: Contraindicated – QT prolongation risk
  • QT-prolonging drugs: Use caution, monitor ECG
  • CYP2C19 inhibitors: May increase citalopram levels
  • Anticoagulants: Increased bleeding risk

Adverse Reactions

Common (≥5%):

  • Nausea, dry mouth, somnolence, insomnia
  • Sweating increased, tremor, diarrhea
  • Sexual dysfunction, fatigue

Serious:

  • QT prolongation, serotonin syndrome, abnormal bleeding

Special Populations

  • Elderly (>60 years): Maximum 20 mg daily due to QT risk
  • Hepatic Impairment: Maximum 20 mg daily
  • CYP2C19 poor metabolizers: Maximum 20 mg daily
  • Pregnancy: Category C – use only if benefits outweigh risks
  • Cardiac monitoring: Consider ECG in patients with cardiac risk factors
Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. Always consult with qualified healthcare professionals before making any treatment decisions. Individual patient circumstances may vary significantly.