What are the potential side effects of citalopram (Selective Serotonin Reuptake Inhibitor) and how should they be managed?

Citalopram Side Effects and Management

Citalopram commonly causes side effects including nausea, sleep disturbances, sexual dysfunction, and QT prolongation, with doses exceeding 40mg daily potentially causing life-threatening cardiac complications. 1, 2

Common Side Effects

Citalopram, like other SSRIs, is associated with several common side effects:

• Gastrointestinal effects:

  • Nausea (most common, affecting up to 20% of patients)
  • Vomiting
  • Diarrhea
  • Constipation 1, 2

• Neurological effects:

  • Headache
  • Dizziness
  • Tremors
  • Insomnia or somnolence 1, 2

• Other common effects:

  • Increased sweating
  • Dry mouth
  • Sexual dysfunction
  • Fatigue/weakness 1, 2

Serious Side Effects

Cardiovascular Effects

• QT prolongation: Citalopram may cause QT prolongation associated with Torsade de Pointes, ventricular tachycardia, and sudden death at daily doses exceeding 40 mg/day 2
• Dose restrictions: Should not exceed 40 mg/day in adults and 20 mg/day in adults over 60 years 1
• Contraindications: Should be avoided in patients with congenital long QT syndrome 1

Neuropsychiatric Effects

• Suicidality: Increased risk of suicidal thinking or behavior, particularly in children, teenagers, and young adults within the first few months of treatment 1
• Serotonin syndrome: Life-threatening condition characterized by agitation, hallucinations, coma, coordination problems, racing heartbeat, high or low blood pressure, sweating, fever, nausea, vomiting, diarrhea, and muscle rigidity 1
• Seizures: Though rare, seizures have been reported 1

Other Serious Effects

• Hyponatremia: Risk of 0.5% to 12% in older adults, typically within the first month of treatment 2
• Abnormal bleeding: Increased risk of bleeding or bruising, especially when taken with antiplatelet drugs, NSAIDs, or aspirin 1
• Discontinuation syndrome: Characterized by dizziness, fatigue, lethargy, headaches, nausea, sensory disturbances, anxiety, irritability, and agitation 2

Management of Side Effects

Initial Dosing and Titration

1. Start low: Begin with 10 mg daily, especially in elderly patients 2
2. Test dose: Consider starting with a subtherapeutic dose as a "test" dose since initial anxiety/agitation can occur 2
3. Gradual titration: Increase dose gradually (every 1-2 weeks) as tolerated 2
4. Maximum dose: Do not exceed 40 mg daily (20 mg in elderly) due to QT prolongation risk 1

Managing Common Side Effects

• Nausea/GI effects: Take with food; symptoms often improve within 1-2 weeks
• Sexual dysfunction: Consider dose reduction if severe or switch to an alternative antidepressant with lower sexual side effect profile
• Sleep disturbances: Adjust timing of dose (morning for insomnia, evening for daytime sedation)
• Sweating: Symptomatic management; consider dose reduction if severe

Managing Serious Side Effects

• QT prolongation: Monitor ECG in high-risk patients; avoid in patients with pre-existing cardiac conditions or concomitant QT-prolonging medications 2
• Serotonin syndrome: Discontinue citalopram and any other serotonergic medications immediately; provide supportive care 1
• Hyponatremia: Monitor sodium levels in elderly patients, especially during the first month 2
• Bleeding risk: Avoid concomitant use with NSAIDs, antiplatelet drugs, or anticoagulants when possible 1

Discontinuation

• Taper gradually over 10-14 days to minimize withdrawal symptoms 2
• Never stop abruptly due to risk of discontinuation syndrome 1

Drug Interactions

• MAOIs: Contraindicated due to risk of serotonin syndrome 2
• QT-prolonging medications: Avoid concomitant use 2
• CYP450 interactions: Citalopram has less effect on CYP450 isoenzymes compared to other SSRIs, resulting in fewer drug interactions 2
• Serotonergic drugs: Use caution with other serotonergic medications (triptans, tramadol, St. John's wort) 1

Special Populations

Elderly

• Start at lower doses (10 mg daily)
• Maximum dose 20 mg daily due to increased risk of QT prolongation 1
• Monitor for hyponatremia 2

Children and Adolescents

• Parental oversight of medication is essential 2
• Monitor height and weight during treatment 1
• Increased risk of suicidal thinking requires close monitoring 1

Monitoring Recommendations

1. Monitor for suicidal thoughts or behaviors, especially in the first few months of treatment
2. Consider ECG monitoring in patients with cardiac risk factors
3. Monitor electrolytes, particularly sodium, in elderly patients
4. Assess for signs of serotonin syndrome when starting treatment or changing doses

Remember that while citalopram has a favorable side effect profile compared to tricyclic antidepressants, careful monitoring and appropriate management of side effects are essential to optimize treatment outcomes and patient safety.