Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the delayed switch group were switched to 5 cm^2 rivastigmine patch formulation on Day 8, following a 7-day withdrawal period from donepezil. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.

Patients randomized to the immediate switch group continued treatment with donepezil through the evening prior to Day 8 of the study. On Day 8, all patients began open-label treatment with 5 cm^2 rivastigmine patch formulation. A new patch was applied daily for 4 weeks. Patients who completed the core phase had the option of entering the extension phase, in which they received open-label treatment with rivastigmine patch formulation for an additional 20 weeks. In the absence of any dose-limiting adverse events (AEs), the dose was increased to 10 cm^2 patch, and it remained the same through Week 25. Patients who experienced dose-limiting AEs had their dose reduced to 5 cm^2 patch and continued on their best tolerated dose for the remainder of the study.