Rivastigmine Patch to Oral Conversion
When converting from rivastigmine patch to oral formulation, use the following direct conversions: 4.6 mg/24-hour patch converts to 3 mg oral twice daily (6 mg/day total), 9.5 mg/24-hour patch converts to 6 mg oral twice daily (12 mg/day total), and 13.3 mg/24-hour patch converts to the maximum oral dose of 6 mg twice daily (12 mg/day total). 1, 2, 3
Conversion Algorithm
From Patch to Oral Dosing
4.6 mg/24-hour patch → Start oral rivastigmine at 1.5 mg twice daily, then titrate up to 3 mg twice daily (6 mg/day total) over 4 weeks 2, 3
9.5 mg/24-hour patch → Start oral rivastigmine at 3 mg twice daily, then titrate to 6 mg twice daily (12 mg/day total) over 4 weeks 1, 2, 3
13.3 mg/24-hour patch → Start oral rivastigmine at 3 mg twice daily, then titrate to the maximum oral dose of 6 mg twice daily (12 mg/day total) over 4 weeks 2, 4
Critical Implementation Details
Titration Schedule
Begin oral dosing the day after removing the final patch 3
Increase oral doses by 1.5 mg twice daily every 4 weeks as tolerated to reach target maintenance dose 2
Always administer oral rivastigmine with meals to minimize gastrointestinal side effects 2, 5
Important Pharmacokinetic Considerations
The patch provides sustained absorption with more stable plasma levels compared to oral formulation, which has peak-trough fluctuations 3, 6
Oral rivastigmine has rapid absorption with bioavailability of 35.5% and elimination half-life less than 2 hours, requiring twice-daily dosing 5
The pseudo-irreversible cholinesterase inhibition lasts up to 10 hours, providing rationale for twice-daily oral dosing 2, 5
Common Pitfalls and Management
Gastrointestinal Side Effects
Expect higher rates of nausea, vomiting, and diarrhea with oral formulation compared to patch (nausea occurs in up to 3.2% with patch vs higher rates with oral) 3, 6
Taking all oral doses with meals significantly reduces gastrointestinal symptoms 2, 5
Most gastrointestinal adverse events occur during titration phase and decrease during maintenance phase 5
Monitoring During Conversion
Assess for cholinergic withdrawal symptoms (acute cognitive decline, behavioral changes) if conversion is not done properly 1
Monitor for dose-related adverse events including nausea, vomiting, diarrhea, weight loss, abdominal pain, headaches, dizziness, fatigue, and anxiety 2
Allow 6-12 months to assess full therapeutic response after conversion 2, 7
Maximum Dosing Limitation
The maximum oral dose is 6 mg twice daily (12 mg/day total), which is equivalent to the 9.5 mg/24-hour patch 2, 3
Patients on the 13.3 mg/24-hour patch cannot achieve equivalent dosing with oral formulation, representing a therapeutic limitation of conversion 4, 8
If patient was on 13.3 mg/24-hour patch due to continued decline on lower doses, converting to oral may result in suboptimal dosing 4
Special Clinical Scenarios
When NOT to Convert
Patients with significant gastrointestinal intolerance to oral medications should remain on patch formulation 3, 6
Patients who achieved stability on 13.3 mg/24-hour patch should not convert to oral, as equivalent dosing is not achievable 4, 8
Elderly patients with age-related changes in drug metabolism may tolerate patch better than oral formulation 2