How to taper Zoloft (sertraline) and switch to Prozac (fluoxetine)?

How to Taper Sertraline (Zoloft) and Switch to Fluoxetine (Prozac)

When switching from sertraline (Zoloft) to fluoxetine (Prozac), implement a gradual tapering schedule of sertraline with dose reductions of approximately 25% of the most recent dose every 1-2 weeks, followed by initiation of fluoxetine at a low dose after sertraline is completely discontinued or at a very low dose. 1

Sertraline Tapering Process

• Begin by reducing sertraline by 25% of the current dose every 1-2 weeks (e.g., from 100 mg to 75 mg, then to 56.25 mg, etc.) 1
• Monitor closely for withdrawal symptoms which may include anxiety, irritability, insomnia, dizziness, electric shock-like sensations, and gastrointestinal disturbances 2
• If withdrawal symptoms occur, slow the taper rate or temporarily return to the previous dose until symptoms subside 1
• For patients on higher doses or who have been on sertraline long-term, an even more gradual taper may be warranted 3
• Continue tapering until reaching the lowest available dose (typically 25 mg for sertraline) 1
• For the final reduction from 25 mg to zero, consider alternate-day dosing for 1-2 weeks before complete discontinuation 3

Initiating Fluoxetine

• Start fluoxetine at a low dose (10 mg every other morning) after sertraline is completely discontinued or at a very low dose 1
• Fluoxetine's very long half-life makes it less likely to cause withdrawal symptoms when eventually discontinued 1
• Increase fluoxetine gradually as needed up to 20 mg every morning 1
• Monitor for side effects which may include activation, nervousness, insomnia, and gastrointestinal disturbances 1

Monitoring During Transition

• Schedule more frequent follow-up appointments during the tapering and switching period to assess for return of original symptoms and emergence of withdrawal symptoms 4
• Be aware that withdrawal symptoms may be mistaken for relapse of the underlying condition 3
• Monitor for potential drug interactions if there is any overlap between sertraline and fluoxetine 2
• Watch for signs of serotonin syndrome if there is any overlap in dosing (symptoms include mental status changes, autonomic instability, neuromuscular symptoms, and gastrointestinal symptoms) 2

Special Considerations

• If the patient is also taking benzodiazepines, consider tapering benzodiazepines separately and with greater caution due to higher risks associated with benzodiazepine withdrawal 5
• Consider adding adjunctive medications temporarily to manage withdrawal symptoms if needed (e.g., trazodone for insomnia) 1
• Withdrawal symptoms should be preempted and treated with liberal use of adjuvant agents along with adequate clinician support 1
• Standard tapering schedules of 2-4 weeks may be too rapid for many patients; hyperbolic tapering (smaller reductions as the dose gets lower) may be more effective in reducing withdrawal symptoms 3, 6

Common Pitfalls to Avoid

• Avoid abrupt discontinuation of sertraline, which can precipitate withdrawal symptoms 2
• Do not mistake withdrawal symptoms for relapse of the original condition 7
• Avoid starting fluoxetine at too high a dose, which may increase side effects 1
• Be cautious about potential drug interactions between sertraline and fluoxetine if there is any overlap in dosing 2
• Do not rush the tapering process; slower tapering is generally more successful in reducing withdrawal symptoms 3