Dosage and usage of donepezil transdermal patch

Donepezil Transdermal System (Donepezil Transdermal System) is a cholinesterase inhibitor used for the treatment of Alzheimer's disease (AD). It maintains stable blood concentration through transdermal absorption. The recommended starting dose is 9.5 mg/24 hours, changed weekly, equivalent to 5 mg donepezil orally. If the patient tolerates it well, it can usually be increased to 19mg/24 hours after 4 to 6 weeks, changing once a week, which is equivalent to the oral dose of 10mg. The highest dose is usually 19 mg/24 hours, and further increases are not recommended to avoid the risk of side effects.

The patch should be applied to clean, dry, hair-free skin, and recommended areas include the back, upper arms, chest, or thighs to reduce skin irritation. A different site should be selected for each replacement, and avoid sticking to the same area continuously to reduce the incidence of contact dermatitis. The patch should not be cut or trimmed to avoid affecting the uniformity of drug release. In addition, although the patch is waterproof to a certain extent, long-term immersion, such as swimming or long bathing, should be avoided to avoid affecting the efficacy.

Special groups should pay attention when using it. The elderly and patients with impaired liver and kidney function should use it under the guidance of a doctor and closely monitor adverse reactions. Patients with cardiovascular disease, especially those with a history of bradycardia, should use it with caution to avoid affecting the heart rate. In addition, patients taking other cholinergic or anticholinergic drugs need to avoid drug interactions that may increase or decrease efficacy.

If the patient misses a patch change, it should be reimbursed as soon as possible, but if it is close to the next change time, it should be skipped directly, and both patches should not be used at the same time. If discontinuation of medication is necessary, it is recommended that the dose be gradually reduced to avoid cognitive decline or mood swings that may result from sudden discontinuation. Patients with long-term use should be followed up regularly, and doctors will adjust the dosage or change the treatment plan according to the condition to ensure the best effect.

References: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/212304s000lbl.pdf