What side effects should be monitored when switching from citalopram (Selective Serotonin Reuptake Inhibitor - SSRI) to bupropion (Norepinephrine-Dopamine Reuptake Inhibitor - NDRI)?

Side Effects to Monitor When Switching from Citalopram to Bupropion

Taper citalopram over 1-2 weeks before starting bupropion to minimize SSRI withdrawal symptoms, then monitor closely for seizures (bupropion's most serious risk), neuropsychiatric symptoms including worsening depression or suicidal ideation, and common side effects like agitation, insomnia, and gastrointestinal symptoms. 1

Critical Safety Concerns

Seizure Risk (Most Serious)

• Bupropion lowers the seizure threshold—this is the most serious side effect requiring vigilance. 2, 3
• Risk is dose-dependent; never exceed 400 mg/day of sustained-release formulation or 450 mg/day of immediate-release. 3
• Contraindicated in patients with seizure disorder, brain metastases, or epilepsy. 1
• Avoid in patients with eating disorders (anorexia nervosa, bulimia nervosa) due to increased seizure risk. 2

Neuropsychiatric Symptoms

• Monitor for worsening depression, suicidal thoughts, or suicidal behavior—particularly critical during the medication transition period. 1
• Watch for anxiety, panic attacks, and agitation. 2, 3
• These symptoms may emerge within the first weeks after switching. 1

SSRI Withdrawal Symptoms (From Citalopram Discontinuation)

Tapering Strategy

• Taper citalopram from 10 mg to 5 mg daily over the first week, then discontinue. 1
• All SSRIs must be tapered slowly to avoid withdrawal symptoms. 1

Withdrawal Symptoms to Monitor

• Dizziness, cognitive impairment (concentration and memory issues). 2
• Dysgeusia (taste disturbances), nausea. 2
• Anxiety and mood changes. 2

Common Bupropion Side Effects

Neurological and Psychiatric

• Agitation and anxiety (very common, may occur early in treatment). 3
• Insomnia and sleep disturbances (dose in morning to minimize). 3
• Headaches and migraines. 3
• Tremor. 3
• Dizziness. 2

Gastrointestinal

• Nausea and vomiting. 3
• Constipation. 3
• Dry mouth (xerostomia). 2

Other Side Effects

• Weight loss (contrast to SSRIs which may cause weight gain). 4
• Tachyarrhythmia and increased heart rate. 2

Cardiovascular Monitoring

• Monitor for increased heart rate and blood pressure. 2
• Watch for cardiac arrhythmias. 2

Contraindications and Drug Interactions

Absolute Contraindications

• MAO inhibitors within 14 days (risk of hypertensive reactions). 2, 1
• Seizure disorders. 2, 1
• Eating disorders (anorexia, bulimia). 2
• Narrow-angle glaucoma. 2, 1

Special Populations

• Patients with severe depression require closer monitoring. 2
• Dose adjustment needed for hepatic or renal impairment. 2
• May reduce effectiveness of tamoxifen in breast cancer patients. 1

Recommended Monitoring Schedule

Initial Phase (First 2-4 Weeks)

• Close monitoring is necessary in the first weeks after the medication switch. 1
• Contact patient (in-person or by phone) after starting bupropion to check for adherence and side effects. 1
• Most improvement occurs within the first 2 weeks. 5
• Full therapeutic effect typically achieved at 4 weeks. 3

Dosing Protocol

• Start bupropion SR 150 mg once daily in the morning for the first 3 days. 1
• Increase to 150 mg twice daily (300 mg total) if well tolerated. 1
• Maximum dose is 300 mg per day for sustained-release formulation. 1

Long-term Monitoring

• If inadequate response after 6-12 weeks, consider switching or augmenting therapy. 1
• Continue monitoring for neuropsychiatric symptoms throughout treatment. 1

Clinical Pitfalls to Avoid

• Do not combine with alcohol or depressant drugs, as this can worsen cognitive impairment. 2
• Do not discontinue bupropion abruptly if on higher doses. 2
• Avoid combining with other medications that lower seizure threshold. 3
• Be aware that bupropion has no serotonergic activity, so SSRI-related sexual dysfunction may improve, but this also means no serotonergic coverage during the switch. 3, 6