BLACK BOX WARNING
- suicidality in children, adolescents, and young adults
citalopram
Brand: Celexa
⚠ BBW Beers Criteria Prototype: fluoxetine
Drug Class: SSRI
Drug Family: antidepressant
Subclass: selective serotonin reuptake inhibitor
Organ Systems: cns
Mechanism of Action
Selectively inhibits the serotonin transporter with high selectivity and minimal effects on norepinephrine or dopamine transporters, CYP enzymes, or muscarinic receptors, making it one of the most selective SSRIs available.
SERT (serotonin transporter)
Indications
- major depressive disorder
- off-label: panic disorder
- off-label: OCD
- off-label: generalized anxiety disorder
Contraindications
- concurrent MAOI use
- concurrent pimozide use
- congenital long QT syndrome
- doses >40 mg/day (QT risk)
Adverse Effects
Common
- nausea
- somnolence
- dry mouth
- increased sweating
- tremor
- sexual dysfunction
Serious
- QT prolongation and torsades de pointes (dose-dependent)
- serotonin syndrome
- hyponatremia (SIADH)
- suicidal ideation
Pharmacokinetics (ADME)
| Absorption | well absorbed orally; bioavailability ~80%; food has no effect |
| Distribution | protein binding ~80%; Vd ~12 L/kg |
| Metabolism | primarily via CYP2C19 and CYP3A4; mild CYP2D6 inhibitor; active metabolite didesmethylcitalopram |
| Excretion | primarily renal with some fecal; dose reduction required if CrCl <20 mL/min and in hepatic impairment |
| Half-life | 35 hours |
| Onset | 1-4 weeks for antidepressant effect |
| Peak | 4 hours |
| Duration | 24 hours |
| Protein Binding | 80% |
| Vd | 12 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| MAOIs | serotonin syndrome | contraindicated |
| pimozide | additive QT prolongation | contraindicated |
| omeprazole (CYP2C19 inhibitors) | increases citalopram exposure and QT risk | moderate |
| linezolid | serotonin syndrome risk | major |
Nursing Considerations
- Maximum dose is 40 mg/day due to QT prolongation risk; 20 mg/day maximum for patients >60 years, those with hepatic impairment, or CYP2C19 poor metabolizers.
- Obtain baseline ECG in patients with known cardiac disease, hypokalemia, or hypomagnesemia before initiating; monitor ECG if dose increases.
- Monitor serum sodium in elderly patients; citalopram can cause SIADH — suspect if patient develops confusion, headache, or neurological changes.
- Educate patients that full antidepressant effect may take 4-6 weeks; partial response at 2 weeks is prognostically favorable.
Clinical Pearls
- Citalopram has the most dose-dependent QT prolongation of all SSRIs; FDA issued a safety communication in 2011 limiting the maximum dose to 40 mg/day.
- Its high selectivity and minimal drug interaction profile make it preferred in medically complex patients requiring polypharmacy.
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.