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citalopram

Adjunctive therapy

Brand: Celexa

Published 2025-12-22 · Last reviewed 2025-12-29 · 4 references

Content sourced from FDA labeling (DailyMed) and peer-reviewed literature.

Print sheet Review evidence

At a glance

Class: Adjunctive therapy·Typical dose: Typical start is 20 mg once daily; increase to 40 mg/day after ≥4 weeks if needed (limit to 20 mg/day for ≥60 years, hepatic impairment, CYP2C19 inhibitors).·Half-life: Single-dose mean 35 h; Steady-state mean 38 h·LAI available: No

Class: Adjunctive therapy
Typical dose: Typical start is 20 mg once daily; increase to 40 mg/day after ≥4 weeks if needed (limit to 20 mg/day for ≥60 years, hepatic impairment, CYP2C19 inhibitors).
Half-life: Single-dose mean 35 h; Steady-state mean 38 h
LAI available: No

Quick answers

What is citalopram?: Citalopram is an SSRI used for major depressive and anxiety disorders in patients with serious mental illness, notable for relatively low drug interactions but dose-dependent QTc prolongation.
What is Celexa?: Celexa is a brand name for citalopram.
What is Celexa (citalopram) used for?: Label indications include: Major depressive disorder.
What drug class is Celexa (citalopram)?: SSRI Antidepressant.
What is the mechanism of action of Celexa (citalopram)?: Selective serotonin reuptake inhibitor (SSRI).
What strengths does Celexa (citalopram) come in?: Tablets 10–40 mg; oral solution 10 mg/5 mL.

General information

Citalopram is an SSRI used for major depressive and anxiety disorders in patients with serious mental illness, notable for relatively low drug interactions but dose-dependent QTc prolongation.

Clinical response often begins within 2–4 weeks, but an adequate trial frequently requires 6–8 weeks at a therapeutic dose; plan for gradual tapering to reduce discontinuation symptoms.

The citalopram compare view, citalopram evidence feed, and citalopram print page can be used together for shared decision-making; the bipolar disorder hub summarizes considerations when balancing antidepressant benefits against mania switch risk in mood disorders.

Sexual dysfunction and sleep disruption are common SSRI-class issues; documenting baseline symptoms helps distinguish medication side effects from the underlying mood/anxiety disorder.

U.S. approvals

Major depressive disorder (1998)

Formulations & strengths

Tablets 10–40 mg; oral solution 10 mg/5 mL.

Generic availability

All formulations available generically.

Dose limited to 40 mg/day (20 mg/day in older adults/hepatic impairment/CYP2C19 inhibitors) due to QTc prolongation; consider escitalopram for lower QT risk.

View labelExact

Mechanism of action

Refer to the Glossary entry on Neurotransmitters for background on receptor systems involved in serious mental illness.

Selectively inhibits serotonin reuptake, increasing synaptic serotonin; little affinity for other receptors.

Selective serotonin transporter inhibitor.

Metabolism & pharmacokinetics

Metabolized via CYP2C19 and CYP3A4 (minor CYP2D6); half-life ~35 h; steady state in 1 week.
Hepatic impairment can increase exposure; dosing caps and slower titration are used to reduce QTc risk and adverse effects.

Dosing & administration

Typical start is 20 mg once daily; increase to 40 mg/day after ≥4 weeks if needed (limit to 20 mg/day for ≥60 years, hepatic impairment, CYP2C19 inhibitors).
Gradual tapering can reduce discontinuation symptoms.
When discontinuation symptoms occur despite tapering, extending the taper interval (smaller steps over longer periods) is often better tolerated than abrupt pauses or rapid reductions.

Monitoring & labs

QTc monitoring when cardiac risk is present or when combining multiple QT-active medications; recheck ECG after dose changes when indicated.
Sodium in older adults or patients on diuretics if symptoms suggest hyponatremia.
Bleeding/bruising risk when combined with NSAIDs, antiplatelets, or anticoagulants; reinforce early symptom reporting.
Mood elevation or agitation in bipolar-spectrum illness; coordinate prevention plans via the bipolar disorder hub.

Citalopram is relatively low-interaction, but dose-dependent QT risk is a key differentiator from other SSRIs; keep documentation clear when higher doses are used or complex polypharmacy is present, or comorbidity.

Adverse effects

FDA boxed warnings

Antidepressants increase suicidality risk in young adults; monitor closely.

Common side effects (≥10%)

Nausea: Typically transient.
Somnolence/insomnia: Dose timing adjustments may help.
Sexual dysfunction: Reduced libido/delayed orgasm common.
Dry mouth: Hydration can help.

Other notable effects

QTc prolongation significant—baseline ECG is often obtained for cardiac risk or doses >20 mg in vulnerable populations.
Hyponatremia (SIADH), especially in elderly; sodium monitoring is considered.
Discontinuation symptoms can occur if stopped abruptly (dizziness, flu-like symptoms, irritability); tapering tends to be better tolerated than sudden discontinuation.
Bleeding risk can increase when combined with NSAIDs, antiplatelets, or anticoagulants; education about bruising and GI bleeding symptoms is important.
Serotonin syndrome is uncommon on monotherapy but becomes more likely with serotonergic combinations; provide escalation guidance for agitation, tremor, clonus, and fever.
Mania/hypomania can emerge in bipolar-spectrum illness; coordinate prevention strategies via the bipolar disorder hub when antidepressants are part of a regimen.

Interactions

CYP2C19 inhibitors (omeprazole, fluconazole) increase levels—limit dose to 20 mg/day and monitor QTc.
Label contraindicates concomitant use with MAOIs/linezolid due to serotonin syndrome risk.
Additive QTc risk with antipsychotics (ziprasidone, haloperidol)—monitor ECG.
Use caution with other serotonergic agents (triptans, tramadol, SNRIs, linezolid, St. John’s wort) that can raise serotonin syndrome risk.

Other useful information

Counseling often covers serotonin syndrome warning signs and when to seek care for palpitations, syncope, or persistent nausea.
Consider escitalopram (S-enantiomer) for patients needing higher potency with similar tolerability.
For patients with elevated QT risk, documentation often includes a monitoring plan (baseline ECG, electrolytes, follow-up after dose changes), and layering multiple QT-active medications is generally avoided when alternatives exist.
When switching antidepressants, the QT plan is often kept explicit (dose caps, ECG timing, and electrolyte checks), and overlapping multiple QT- and serotonergic-active medications is generally avoided when alternatives exist.

References

Related hubs:SMI toolkit·Support resources