Cutaneous Reaction to Rivastigmine Patch

Because of polypharmacy, a 67-year-old man who had multiple medical problems, including urinary incontinence, heart block that required pacemaker implantation, and recently diagnosed Alzheimer dementia, was noncompliant with his medication for dementia. He was subsequently switched from an oral medication to a rivastigmine patch. The patient and his home attendant were educated about the use of the patch and application sites.

During a follow-up visit, he was noted to be scratching his gluteal region. The home attendant was concerned about irritation caused by diapers. Physical examination revealed several sharply demarcated round discrete erythematous lesions over his left gluteal region.

It was subsequently noticed that patient was applying the rivastigmine patch over his gluteal region because of concerns about his pacemaker. The rivastigmine patch was discontinued, and the patient was switched back to an oral medication. The skin lesions and irritation gradually resolved.

Transdermal therapeutic systems (TTS) have been widely used over the past 2 decades in drug delivery. They provide the benefits of both convenience and medication compliance, especially in the elderly population, in whom polypharmacy is a concern because of the multiple co-morbidities of these patients.

TTS come in various forms: multilayer drug-in-adhesive, single-layer drug-in-adhesive, reservoir, matrix, and vapor forms. The rivastigmine patch is a thin, matrix-type transdermal system consisting of four layers. Other drugs delivered by TTS include clonidine, scopolamine, estradiol, lidocaine, fentanyl, and nicotine.

Skin irritation is the most commonly reported cutaneous side effect of TTS use in general and usually resolves on discontinuation of the patch.¹ Most of these cutaneous manifestations are associated with allergens that may be from the active medication itself or other active component of the system, including irritants such as ethanol, glycerin, acryl aldehyde, and silicone.² Management of these cutaneous reactions includes change of application sites, trial of alternative brands, application for a shorter duration, and pretreatment of the skin with topical corticosteroids.³ A transition back to oral medications has been successful in most persons who have not tolerated these TTS, as in this patient.