Switching from Sertraline (Zoloft) to Duloxetine (Cymbalta)
The recommended protocol for switching from Zoloft to Cymbalta is to start with Cymbalta 30mg once daily for one week while gradually reducing Zoloft, then increase to Cymbalta 60mg once daily as you continue tapering off Zoloft completely over 2-4 weeks. 1
Cross-Tapering Schedule
- Week 1: Start Cymbalta 30mg once daily and reduce Zoloft to 75% of original dose
- Week 2: Increase Cymbalta to 60mg once daily and reduce Zoloft to 50% of original dose
- Week 3: Continue Cymbalta 60mg once daily and reduce Zoloft to 25% of original dose
- Week 4: Continue Cymbalta 60mg once daily and discontinue Zoloft completely
This gradual cross-tapering approach minimizes the risk of discontinuation syndrome while ensuring adequate treatment coverage during the transition.
Rationale for Cross-Tapering
- Abrupt discontinuation of Zoloft can lead to withdrawal symptoms including dizziness, fatigue, headaches, nausea, sensory disturbances, anxiety, and irritability 1
- Duloxetine also has potential discontinuation symptoms when stopped abruptly, with dizziness being the most common (12.4%), followed by nausea (5.9%), headache (5.3%), and paresthesia (2.9%) 2
- Starting with a lower dose of Cymbalta (30mg) reduces the risk of initial side effects, particularly nausea 1
Monitoring During Cross-Tapering
Schedule follow-up within 1-2 weeks of initiating the cross-taper to assess:
- Withdrawal symptoms from Zoloft
- Adverse effects from Cymbalta
- Changes in mood, anxiety, or suicidal ideation 1
Monitor closely for serotonin syndrome during the cross-taper period, especially in the first 24-48 hours after dosage changes 1
- Symptoms include: agitation, tremor, hyperthermia, autonomic instability, and mental status changes
Potential Adverse Effects
- Common Cymbalta side effects include diaphoresis, dry mouth, abdominal discomfort, nausea, vomiting, diarrhea, dizziness, headache, tremor, insomnia, somnolence, decreased appetite, and weight loss 3
- Cymbalta may cause increased blood pressure and pulse, requiring monitoring 3
- Serious but rare adverse effects include suicidal thinking (through age 24), behavioral activation, hypomania, mania, sexual dysfunction, seizures, abnormal bleeding, and serotonin syndrome 3
Contraindications for This Cross-Taper
- Concomitant use of MAOIs (monoamine oxidase inhibitors) is absolutely contraindicated due to risk of serotonin syndrome 3
- Severe hepatic impairment (Cymbalta has been associated with hepatic failure) 3
- Uncontrolled narrow-angle glaucoma 1
Common Pitfalls to Avoid
- Tapering too quickly: Increases risk of withdrawal symptoms and may compromise treatment efficacy 1, 4
- Starting Cymbalta at too high a dose: Increases risk of nausea and other initial side effects 1
- Inadequate monitoring: Regular follow-up is essential during the cross-taper period 1
- Overlooking drug interactions: Duloxetine may interact with drugs metabolized by CYP1A2 and CYP2D6 3
This cross-tapering approach balances the need to minimize discontinuation symptoms while ensuring adequate treatment coverage during the transition from Zoloft to Cymbalta.