Switching from Celexa (Citalopram) to Zoloft (Sertraline)
Stop citalopram abruptly and start sertraline 50 mg daily the next day without a washout period, as both are SSRIs with similar mechanisms and short half-lives that allow for direct switching. 1, 2
Switching Protocol
Direct Cross-Taper Approach (Recommended)
Discontinue citalopram immediately and initiate sertraline 50 mg daily the following day, as the short half-life of citalopram (approximately 35 hours) does not require a washout period when switching between SSRIs 2
No tapering of citalopram is necessary for most patients, as both medications are SSRIs with similar receptor profiles and minimal risk of serotonin syndrome when directly switched 1, 2
Monitor for SSRI discontinuation symptoms during the first 1-2 weeks, including dizziness, nausea, headache, and irritability, though these are typically mild with citalopram due to its relatively short half-life 2
Dosing Considerations
Start sertraline at 50 mg daily for most adults, which is the standard initial therapeutic dose 1, 3
For elderly patients (>65 years) or those with hepatic impairment, consider starting sertraline at 25 mg daily and titrating up to 50 mg after 1 week to minimize adverse effects 1
Maximum dose of sertraline can be increased to 200 mg daily if needed after 4-6 weeks, based on clinical response 1
Important Safety Considerations
Avoid exceeding citalopram 40 mg daily (or 20 mg daily in adults >60 years) prior to the switch due to dose-dependent QT prolongation risk, which is a unique concern with citalopram but not sertraline 1
Monitor for serotonin syndrome during the first week after switching, watching for the triad of mental status changes, neuromuscular hyperactivity (tremor, hyperreflexia, clonus), and autonomic instability (tachycardia, hypertension, hyperthermia) 4
Assess for gastrointestinal bleeding risk, particularly if the patient is taking concurrent NSAIDs or antiplatelet agents, as both SSRIs carry similar bleeding risk (OR 1.2-1.5) 1
Monitoring Timeline
Week 1-2: Assess for discontinuation symptoms from citalopram and initial tolerability of sertraline 2
Week 4-6: Evaluate treatment response and consider dose adjustment if inadequate improvement in depressive symptoms 1, 4
Week 12: Reassess for sustained response and tolerability, as both medications show comparable efficacy in treating depression 3
Clinical Pitfalls to Avoid
Do not use a conservative washout period (waiting days between medications) as this unnecessarily exposes the patient to untreated depression and increases relapse risk 2
Do not combine or overlap both medications for extended periods, as this increases serotonin syndrome risk without clinical benefit 4, 2
Do not assume treatment failure if response is inadequate at 2-3 weeks; both SSRIs require 4-6 weeks at therapeutic doses for full antidepressant effect 1
Special Population Adjustments
Pregnancy (after 20 weeks gestation): Both medications carry uncertain risk for persistent pulmonary hypertension of the newborn, though sertraline is preferred during breastfeeding due to lower infant plasma concentrations 1
Patients with dementia: Both citalopram and sertraline are agents of choice due to minimal anticholinergic effects, making the switch straightforward 1
Patients on multiple medications: Check for drug interactions, particularly with other serotonergic agents, anticoagulants, or medications metabolized by CYP2D6 1, 2