CELEXA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CELEXA (CELEXA).
Selective serotonin reuptake inhibitor (SSRI); potentiates serotonergic activity in the CNS by blocking reuptake of serotonin into presynaptic neurons.
| Metabolism | Hepatic via CYP2C19 (major), CYP3A4, and CYP2D6; active metabolites: S-demethylcitalopram and didemethylcitalopram. |
| Excretion | Primarily renal: 75% as metabolites (10% as parent citalopram, 65% as desmethylcitalopram, didesmethylcitalopram, and citalopram-N-oxide). Fecal excretion accounts for approximately 20% of the dose. Biliary excretion minimal. |
| Half-life | Terminal elimination half-life is approximately 35 hours (range 23–45 h) in healthy adults. This long half-life allows once-daily dosing; steady state is reached in about 1 week. In elderly patients, half-life may extend to 45–90 hours. |
| Protein binding | Approximately 80% bound to plasma proteins (primarily albumin and α1-acid glycoprotein). Binding is independent of drug concentration. |
| Volume of Distribution | Mean Vd is 12 L/kg (range 8–16 L/kg). This large Vd indicates extensive extravascular distribution, including CNS penetration. High Vd contributes to the long half-life. |
| Bioavailability | Oral bioavailability is approximately 80% (range 60–90%). No significant first-pass metabolism. Food does not affect bioavailability. |
| Onset of Action | Oral: Antidepressant effect typically begins within 1–4 weeks, with initial improvements in sleep, appetite, and anxiety often seen in the first 2 weeks. No parenteral route available. |
| Duration of Action | Due to the long half-life, therapeutic effects persist for several days after discontinuation. To avoid withdrawal, taper over 1–2 weeks. Duration of single-dose effects: minimal; clinical benefit requires chronic dosing. |
| Action Class | Selective Seretonin Reuptake inhibitors (SSRIs) |
| Brand Substitutes | Lopram 10mg Tablet, C-Talo 10mg Tablet, Madam 10mg Tablet, Cetadep 10mg Tablet, Citadep 10mg Tablet, Lopram 20mg Tablet, C-Talo 20mg Tablet, Celepra 20mg Tablet, Cytop 20mg Tablet, Madam 20mg Tablet |
20 mg orally once daily initially, may increase to 40 mg once daily after at least 1 week; maximum 40 mg/day.
| Dosage form | TABLET |
| Renal impairment | GFR >20 mL/min: no adjustment; GFR ≤20 mL/min: maximum 20 mg/day; not recommended for GFR <10 mL/min. |
| Liver impairment | Child-Pugh Class A: 10 mg once daily; Child-Pugh Class B or C: maximum 20 mg/day with careful titration. |
| Pediatric use | Adolescents 12-17 years: 10 mg orally once daily initially, may increase to 20 mg once daily after 3 weeks; maximum 20 mg/day. Children <12 years: not approved. |
| Geriatric use | Patients >60 years: 10 mg orally once daily initially, maximum 20 mg once daily. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CELEXA (CELEXA).
| Breastfeeding | Citalopram is excreted into breast milk; average infant dose relative to maternal weight-adjusted dose is 3.9% (range 1.7-8.5%). Milk-to-plasma ratio (M/P) approximately 1.5. Cases of adverse effects in breastfed infants (excessive somnolence, poor feeding) reported; caution with higher maternal doses. Benefits of breastfeeding generally outweigh risks for mild cases, but alternative agents with lower M/P (e.g., sertraline, paroxetine) may be preferred for moderate-severe depression. |
| Teratogenic Risk | First trimester: Data insufficient to definitively assess major malformation risk; some studies suggest small increased risk of cardiac defects (e.g., septal defects). Second/Third trimester: Risk of persistent pulmonary hypertension of the newborn (PPHN), preterm birth, low birth weight; late third trimester exposure may cause neonatal adaptation syndrome (irritability, respiratory distress, feeding difficulties). |
■ FDA Black Box Warning
Increased risk of suicidal thinking and behavior in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders.
| Serious Effects |
Concomitant use with MAOIs or within 14 days of MAOI use, concomitant use with pimozide, hypersensitivity to citalopram or any excipients.
| Precautions | QT prolongation, serotonin syndrome, hyponatremia, increased risk of bleeding, activation of mania/hypomania, seizures, angle-closure glaucoma, sexual dysfunction, and discontinuation syndrome. |
| Food/Dietary | No specific food interactions. Avoid grapefruit and grapefruit juice as they may increase citalopram levels via CYP3A4 inhibition. Alcohol may exacerbate CNS depression and should be avoided. |
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| Fetal Monitoring | Prenatal: Screening for fetal anomalies (anatomy ultrasound) if first-trimester exposure; fetal echocardiography if concerns from population studies. Late pregnancy: Monitor for signs of PPHN, preterm labor. Neonatal: Observe for adaptation syndrome (e.g., respiratory distress, feeding intolerance, jitteriness) for at least 48 hours. Maternal: Monitor for worsening depression, suicidal ideation, serotonin syndrome (especially with co-prescribed serotonergic drugs). |
| Fertility Effects | Human data limited; citalopram may cause reversible ejaculatory dysfunction and decreased libido in men; effects on spermatogenesis or oocyte quality not well characterized. No clear evidence of impaired fertility in women; but serotonin reuptake inhibition may influence hypothalamic-pituitary-gonadal axis. Discontinuation of treatment should be weighed against risk of relapse for mood disorders. |
| Clinical Pearls | Celexa (citalopram) is an SSRI antidepressant. Key pearls: (1) Max dose 40 mg/day due to QT prolongation risk at higher doses; (2) CYP2C19 and CYP3A4 metabolism; avoid with MAOIs and linezolid; (3) Onset of therapeutic effect takes 2-4 weeks; (4) More selective for serotonin reuptake than fluoxetine or paroxetine, with fewer drug interactions; (5) May cause mild SIADH in elderly; (6) Abrupt discontinuation can cause withdrawal syndrome; (7) Electrolyte monitoring recommended in patients at risk for QT prolongation. |
| Patient Advice | Take exactly as prescribed; do not increase dose without consulting your doctor. · It may take 2-4 weeks to feel the full benefit; do not stop abruptly. · Avoid alcohol while taking this medication. · Report any symptoms of serotonin syndrome (agitation, hallucinations, rapid heart rate, fever, muscle stiffness) immediately. · Notify your doctor if you experience unusual bleeding or bruising, or if you have a history of QT prolongation or electrolyte disturbances. |