Citalopram (Celexa): Uses, Dosage, Side Effects, and What to Expect

Citalopram (brand name: Celexa) is a selective serotonin reuptake inhibitor (ssri). Citalopram is a racemic mixture of R-citalopram and S-citalopram (escitalopram). The S-enantiomer is responsible for nearly all of the serotonin reuptake inhibition, while the R-enantiomer is largely inactive and may actually counteract some beneficial effects. This is why escitalopram (the pure S-enantiomer) was developed. Citalopram is otherwise a relatively selective SSRI with fewer drug interactions than most alternatives, making it a practical choice for patients on multiple medications.

• Major Depressive Disorder

Common off-label uses:

• Generalized Anxiety Disorder
• Panic Disorder
• Social Anxiety Disorder
• OCD
• PMDD
• Binge Eating Disorder

Start 20 mg once daily. Maximum 40 mg/day (FDA dose ceiling due to QT prolongation). Elderly and hepatic impairment: maximum 20 mg/day. CYP2C19 poor metabolizers: maximum 20 mg/day. Can be taken morning or evening.

Some improvement in 1-2 weeks. Full antidepressant effect in 4-6 weeks.

• Nausea
• Dry mouth
• Drowsiness
• Insomnia
• Increased sweating
• Sexual dysfunction
• Tremor
• Diarrhea

• Dose-dependent QT prolongation (risk of torsades de pointes at doses >40 mg — FDA safety alert 2011)
• Serotonin syndrome
• Suicidal ideation in young adults
• Hyponatremia
• Abnormal bleeding

Fewer CYP450-mediated interactions than most SSRIs (does not significantly inhibit CYP2D6). However, avoid doses >20 mg with CYP2C19 inhibitors (omeprazole, esomeprazole, cimetidine, fluconazole). Avoid with other QT-prolonging drugs. Contraindicated with MAOIs and pimozide.

Category C. Similar risk profile to other SSRIs. No unique teratogenic signal compared to other SSRIs.

Taper gradually over 1-2 weeks. Discontinuation symptoms are moderate — less severe than paroxetine or venlafaxine but more notable than fluoxetine.