How to transition a patient from rivastigmine (Exelon) 1.5 mg twice daily (BID) to the Exelon (rivastigmine) patch?

Transitioning from Rivastigmine 1.5 mg BID to Exelon Patch

When transitioning a patient from rivastigmine oral 1.5 mg twice daily to the Exelon patch, start with the 4.6 mg/24-hour patch (5 cm²), as this provides equivalent systemic exposure to the 3 mg total daily oral dose. 1

Conversion Algorithm

Step 1: Determine Equivalent Patch Dose

• For rivastigmine oral 1.5 mg BID (3 mg/day total), initiate the 4.6 mg/24-hour patch 1
• The 4.6 mg/24-hour patch is the starting dose for patch therapy and provides comparable drug delivery to low-dose oral rivastigmine 2, 3
• Higher oral doses require correspondingly higher patches: the 9.5 mg/24-hour patch approximates 6 mg oral twice daily (12 mg/day total) 1

Step 2: Timing of Transition

• Apply the first patch on the morning after the last oral dose 2
• This approach avoids both treatment gaps (which can cause cholinergic withdrawal with acute cognitive decline and behavioral symptoms) and excessive overlap 1
• Do not overlap oral and patch dosing, as this increases risk of cholinergic side effects 3

Step 3: Patch Application Instructions

• Apply to clean, dry, hairless skin on the upper or lower back, upper arm, or chest 2, 3
• Rotate application sites daily to minimize skin irritation 2
• Replace the patch every 24 hours at approximately the same time each day 3
• Ensure good adhesion; the patch formulation demonstrates satisfactory adhesion in clinical studies 4

Monitoring and Dose Titration

Initial Monitoring (First 4 Weeks)

• Assess for gastrointestinal side effects (nausea, vomiting, diarrhea), which are typically milder with patch versus oral formulation 2, 3
• Monitor for application-site reactions, though most are mild in severity 2, 3
• Evaluate cognitive and functional status using caregiver reports and clinical assessment 5, 6

Dose Escalation Strategy

• If the patient tolerates the 4.6 mg/24-hour patch well but requires higher dosing based on their previous oral regimen or clinical response, increase to the 9.5 mg/24-hour patch after at least 4 weeks 5, 6
• The 9.5 mg/24-hour patch is the recommended maintenance dose for most patients 7
• For patients experiencing continued functional and cognitive decline on the 9.5 mg/24-hour patch, consider escalation to the 13.3 mg/24-hour patch, which provides additional benefit with acceptable tolerability 7

Key Advantages of Patch Formulation

• The transdermal patch provides more consistent drug delivery with reduced peak-to-trough fluctuations compared to oral dosing 2, 3
• Gastrointestinal side effects (nausea, vomiting, diarrhea) are significantly reduced with patch versus oral rivastigmine 2, 3
• Once-daily application improves adherence compared to twice-daily oral dosing 2, 3
• The patch maintains efficacy equivalent to oral formulation while improving tolerability 2, 3

Critical Pitfalls to Avoid

Underdosing During Conversion

• Inadequate dose conversion creates an effective underdosing situation that can precipitate acute cognitive decline and hallucinations 1
• Always match the total daily oral dose to the appropriate patch strength 1
• If symptoms emerge after conversion, immediately increase to the next patch strength rather than reverting to oral therapy 1

Premature Discontinuation

• Allow 6-12 months of treatment to assess full therapeutic response before considering discontinuation 6, 1
• Brief mental status tests are relatively insensitive measures of cholinesterase inhibitor effects; use comprehensive caregiver assessments and functional measures 6

Managing Side Effects

• Most application-site reactions are mild and can be managed with site rotation 2, 3
• If gastrointestinal symptoms occur despite patch use, they typically resolve with continued treatment 2
• The patch formulation has a more favorable tolerability profile than oral rivastigmine, making it less likely to require discontinuation 2, 3