Recommended Dosing Regime for Paroxetine
The recommended initial dose of paroxetine is 20 mg once daily, which is both the starting dose and the minimal effective dose for most patients. 1, 2
Initial Dosing and Administration
- Paroxetine should be administered as a single daily dose with or without food, usually in the morning 1
- For major depressive disorder, the recommended initial dose is 20 mg/day 1
- For most patients, 20 mg/day will be the optimal therapeutic dose 2
- For elderly patients, the therapeutic dose range is 20 mg to 40 mg daily 2
Dose Adjustments
- For patients who do not show adequate therapeutic response within 1-3 weeks, the dose can be increased in 10-mg increments 1, 2
- Dose changes should occur at intervals of at least 1 week to allow for assessment of effects 1
- The maximum recommended dose is 50 mg/day for depression 1, 2
Condition-Specific Dosing
- For obsessive-compulsive disorder (OCD): Start with 20 mg/day, target dose is 40 mg/day, maximum 60 mg/day 1
- For panic disorder: Start with 10 mg/day, target dose is 40 mg/day, maximum 60 mg/day 1
- For social anxiety disorder: Initial and recommended dose is 20 mg/day 1
- For generalized anxiety disorder: Initial and recommended dose is 20 mg/day 1
Duration of Treatment
- For a first episode of major depressive disorder, treatment should continue for 4 to 12 months after remission 3
- For recurrent depression, prolonged treatment may be beneficial 3
- Systematic evaluation has shown that efficacy is maintained for periods up to 1 year with doses averaging about 30 mg 1
- Patients should be periodically reassessed to determine the need for continued treatment 1
Special Considerations
- Paroxetine is less activating but more anticholinergic than other SSRIs 3
- Paroxetine may not be ideal for older adults due to its anticholinergic effects 3
- CYP2D6 poor metabolizers may have higher plasma concentrations of paroxetine and may require lower doses 3
- Common side effects include nausea, sexual dysfunction, somnolence, asthenia, headache, constipation, dizziness, sweating, tremor, and decreased appetite 4, 5
- Lower doses (12.5 mg) of paroxetine controlled release (CR) have shown efficacy with improved tolerability profile, though 25 mg CR demonstrated more robust effects 6
Discontinuation
- Paroxetine has been associated with discontinuation syndrome 3
- To limit withdrawal symptoms, gradual dose reduction over 10 to 14 days is recommended when discontinuing 3
Monitoring
- Assess response to treatment within 1-3 weeks of initiating therapy 2
- Monitor for side effects, especially in the first few weeks of treatment 1
- Be alert for potential drug interactions, particularly with medications metabolized by CYP2D6 3
Paroxetine's favorable efficacy profile combined with once-daily dosing makes it a valuable option for treating depression and anxiety disorders, though careful attention to dosing and potential side effects is essential for optimal outcomes 7.