Exelon Patch Starting Dose for Mild to Moderate Dementia
The starting dose of the Exelon (rivastigmine) transdermal patch is 4.6 mg/24 hours (5 cm² patch), applied once daily. 1, 2
Initial Dosing Protocol
Begin with the 4.6 mg/24 hours patch applied to clean, dry, hairless skin on the upper or lower back, upper arm, or chest, rotating application sites daily. 1, 2
Maintain the starting dose for a minimum of 4 weeks before considering dose escalation to allow assessment of tolerability and initial therapeutic response. 3, 4
The 4.6 mg/24 hours starting dose applies to both treatment-naïve patients and those transitioning from other cholinesterase inhibitors. 5
Dose Titration Strategy
After at least 4 weeks on the starting dose, increase to 9.5 mg/24 hours (10 cm² patch) if the patient tolerates the initial dose well and requires higher dosing based on clinical response. 3, 1
The 9.5 mg/24 hours patch is considered the recommended maintenance dose for most patients with mild to moderate Alzheimer's disease. 1, 2
For patients experiencing continued functional and cognitive decline on the 9.5 mg/24 hours patch, escalation to 13.3 mg/24 hours (15 cm² patch) can be considered after adequate trial duration. 4, 1
Evidence Supporting This Approach
The rivastigmine transdermal patch formulation provides continuous drug delivery with improved tolerability compared to oral capsules, particularly regarding gastrointestinal side effects like nausea and vomiting. 2, 5
In clinical trials, rivastigmine at doses of 6-12 mg daily orally or 9.5 mg daily transdermally demonstrated statistically significant benefits on cognitive function (ADAS-Cog improvement of -2.1 points), activities of daily living, and clinician-rated global assessment compared to placebo. 2
Real-world effectiveness data from 1204 patients showed that the rivastigmine patch maintained cognitive function over 18 months with 88.2% of caregivers preferring the transdermal patch to oral medications. 5
Critical Dosing Considerations
Abrupt switching from oral rivastigmine to patch without proper dose conversion creates effective underdosing, which can precipitate cholinergic withdrawal manifesting as acute cognitive decline and hallucinations. 3
When converting from oral rivastigmine, patients on 6 mg oral twice daily should transition to the 9.5 mg/24 hours patch, not the 4.6 mg/24 hours starting dose, to maintain therapeutic equivalence. 3
Allow 6-12 months to assess full therapeutic response after reaching maintenance dosing, as cognitive benefits may take time to manifest. 3, 4
Monitoring for Adverse Effects
The most common adverse events are nausea, vomiting, diarrhea, anorexia, and dizziness, consistent with cholinergic effects. 2, 6
These side effects can be managed by ensuring the patch is applied after meals and monitoring for skin reactions at application sites. 3
Patients receiving rivastigmine are approximately twice as likely to withdraw from treatment compared to placebo (OR 2.01), primarily due to gastrointestinal adverse events. 2