"Today, the U.S. Food and Drug Administration issued a proposal designed to assist companies developing new treatments for patients in the early stages of Alzheimer's disease, before the onset of noticeable (overt) dementia.
Medication Errors Resulting in Overdose
Medication errors with Exelon Patch have resulted in serious adverse reactions; some cases have required hospitalization, and rarely, led to death. The majority of medication errors have involved not removing the old patch when putting on a new one and the use of multiple patches at one time. Instruct patients and their caregivers on important administration instructions for Exelon Patch. [see DOSAGE AND ADMINISTRATION].
Gastrointestinal Adverse Reactions
Exelon Patch can cause gastrointestinal adverse reactions, including significant nausea, vomiting, diarrhea, anorexia/decreased appetite, and weight loss. Dehydration may result from prolonged vomiting or diarrhea and can be associated with serious outcomes. The incidence and severity of these reactions are dose-related [see ADVERSE REACTIONS]. For this reason, initiate treatment with Exelon Patch at a dose of 4.6 mg/24 hours and titrate to a dose of 9.5 mg/24 hours and then to a dose of 13.3 mg/24 hours, if appropriate [see DOSAGE AND ADMINISTRATION].
If treatment is interrupted for more than three days because of intolerance, reinitiate Exelon Patch with the 4.6 mg/24 hours dose to reduce the possibility of severe vomiting and its potentially serious sequelae. A postmarketing report described a case of severe vomiting with esophageal rupture following inappropriate reinitiation of treatment of an oral formulation of rivastigmine without retitration after 8 weeks of treatment interruption.
Inform caregivers to monitor for gastrointestinal adverse reactions and to inform the physician if they occur. It is critical to inform caregivers that if therapy has been interrupted for more than three days because of intolerance, the next dose should not be administered without contacting the physician regarding proper retitration.
Skin application site reactions may occur with Exelon Patch and are usually mild or moderate in intensity. These reactions are not in themselves an indication of sensitization. However, use of rivastigmine patch may lead to allergic contact dermatitis.
Allergic contact dermatitis should be suspected if application site reactions spread beyond the patch size, if there is evidence of a more intense local reaction (e.g. increasing erythema, edema, papules, vesicles) and if symptoms do not significantly improve within 48 hours after patch removal. In these cases, treatment should be discontinued [see CONTRAINDICATIONS].
In patients who develop application site reactions to Exelon Patch suggestive of allergic contact dermatitis and who still require rivastigmine, treatment should be switched to oral rivastigmine only after negative allergy testing and under close medical supervision. It is possible that some patients sensitized to rivastigmine by exposure to rivastigmine patch may not be able to take rivastigmine in any form.
There have been isolated postmarketing reports of patients experiencing disseminated hypersensitivity reactions of the skin when administered rivastigmine irrespective of the route of administration (oral or transdermal). In these cases, treatment should be discontinued [see CONTRAINDICATIONS]. Patients and caregivers should be instructed accordingly.
Other Adverse Reactions from Increased Cholinergic Activity
Extrapyramidal Symptoms: Cholinomimetics, including rivastigmine may exacerbate or induce extrapyramidal symptoms. Worsening of parkinsonian symptoms, particularly tremor, has been observed in patients with dementia associated with Parkinson's disease who were treated with Exelon capsules.
Peptic Ulcers/Gastrointestinal Bleeding
Cholinesterase inhibitors, including rivastigmine, may increase gastric acid secretion due to increased cholinergic activity. Monitor patients using Exelon Patch for symptoms of active or occult gastrointestinal bleeding, especially those at increased risk for developing ulcers, e.g., those with a history of ulcer disease or those receiving concurrent nonsteroidal anti-inflammatory drugs (NSAIDs). Clinical studies of rivastigmine have shown no significant increase, relative to placebo, in the incidence of either peptic ulcer disease or gastrointestinal bleeding.
Use with Anesthesia
Rivastigmine, as a cholinesterase inhibitor, is likely to exaggerate succinylcholine-type muscle relaxation during anesthesia.
Cardiac Conduction Effects
Because rivastigmine increases cholinergic activity, use of the Exelon Patch may have vagotonic effects on heart rate (e.g., bradycardia). The potential for this action may be particularly important in patients with sick sinus syndrome or other supraventricular cardiac conduction conditions. In clinical trials, rivastigmine was not associated with any increased incidence of cardiovascular adverse events, heart rate or blood pressure changes, or ECG abnormalities.
Although not observed in clinical trials of rivastigmine, drugs that increase cholinergic activity may cause urinary obstruction.
Drugs that increase cholinergic activity, including Exelon Patch should be used with care in patients with a history of asthma or obstructive pulmonary disease.
Impairment in Driving or Use of Machinery
Dementia may cause gradual impairment of driving performance or compromise the ability to use machinery. The administration of rivastigmine may also result in adverse reactions that are detrimental to these functions. During treatment with the Exelon Patch, routinely evaluate the patient's ability to continue driving or operating machinery.
Patient Counseling Information
See FDA-approved patient labeling (PATIENT INFORMATION).
Importance of Correct Usage
Inform patients or caregivers of the importance of applying the correct dose on the correct part of the body. They should be instructed to rotate the application site in order to minimize skin irritation. The same site should not be used within 14 days. The previous day's patch must be removed before applying a new patch to a different skin location. Exelon Patch should be replaced every 24 hours and the time of day should be consistent. It may be helpful for this to be part of a daily routine, such as the daily bath or shower. Only one patch should be worn at a time.
Instruct patients or caregivers to avoid exposure of the patch to external heat sources (excessive sunlight, saunas, solariums) for long periods of time.
Instruct patients who have missed a dose to apply a new patch immediately. They may apply the next patch at the usual time the next day. Instruct patients to not apply two patches to make up for one missed.
Inform the patient or caregiver to contact the physician for retitration instructions if treatment has been interrupted.
Discarding Used Patches
Instruct patients or caregivers to fold the patch in half after use, return the used patch to its original pouch, and discard it out of the reach and sight of children and pets. They should also be informed that drug still remains in the patch after 24-hour usage. They should be instructed to avoid eye contact and to wash their hands after handling the patch. In case of accidental contact with the eyes, or if their eyes become red after handling the patch, they should be instructed to rinse immediately with plenty of water and to seek medical advice if symptoms do not resolve.
Gastrointestinal Adverse Reactions
Inform patients or caregivers of the potential gastrointestinal adverse reactions such as nausea, vomiting, and diarrhea, including the possibility of dehydration due to these symptoms. Explain that Exelon Patch may affect the patient's appetite and/or the patient's weight. Patients and caregivers should be instructed to look for these adverse reactions, in particular when treatment is initiated or the dose is increased. Instruct patients and caregivers to inform a physician if these adverse reactions persist.
Inform patients or caregivers about the potential for allergic contact dermatitis reactions to occur. Patients or caregivers should be instructed to inform a physician if application site reactions spread beyond the patch size, if there is evidence of a more intense local reaction (e.g., increasing erythema, edema, papules, vesicles) and if symptoms do not significantly improve within 48 hours after patch removal.
Concomitant Use of Drugs with Cholinergic Action
Inform patients or caregivers that while wearing Exelon Patch, patients should not be taking Exelon capsules or Exelon oral solution or other drugs with cholinergic effects.
Carcinogenesis, Mutagenesis, Impairment of Fertility
In oral carcinogenicity studies conducted at doses up to 1.1 mg base/kg/day in rats and 1.6 mg base/kg/day in mice, rivastigmine was not carcinogenic.
In a dermal carcinogenicity study conducted at doses up to 0.75 mg base/kg/day in mice, rivastigmine was not carcinogenic. The mean rivastigmine plasma exposure (AUC) at this dose was less than that in humans at the maximum recommended human dose (13.3 mg/24 hours).
Rivastigmine was clastogenic in in vitro chromosomal aberration assays in mammalian cells in the presence, but not the absence, of metabolic activation. Rivastigmine was negative in an in vitro bacterial reverse mutation (Ames) assay, an in vitro HGPRT assay, and in an in vivo mouse micronucleus test.
Impairment of Fertility
No fertility or reproduction studies of dermal rivastigmine have been conducted in animals. Rivastigmine had no effect on fertility or reproductive performance in rats at oral doses up to 1.1 mg base/kg/day.
Use In Specific Populations
Pregnancy Category B
There are no adequate and well-controlled studies in pregnant women. No dermal reproduction studies in animals have been conducted. Oral reproduction studies conducted in pregnant rats and rabbits revealed no evidence of teratogenicity. Studies in rats showed slightly decreased fetal/pup weight, usually at doses causing some maternal toxicity. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Rivastigmine and its metabolites are excreted in rat milk following oral administration of rivastigmine; levels of rivastigmine plus metabolites in rat milk are approximately two times that in maternal plasma. It is not known whether rivastigmine is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Exelon Patch, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Safety and effectiveness in pediatric patients have not been established. Use of Exelon Patch in children and adolescents (below 18 years of age) is not recommended.
Of the total number of subjects in clinical studies of Exelon Patch, 88% were 65 and over, while 55% were 75 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
No dose adjustment is necessary for patients with renal impairment [see CLINICAL PHARMACOLOGY].
In patients with mild or moderate hepatic impairment (Child-Pugh score 5 to 9), clearance of oral rivastigmine was reduced [see CLINICAL PHARMACOLOGY]. In these patients, consider using the lowest dose Exelon Patch (4.6 mg/24 hours) for both initial and maintenance therapy. No data are available on the use of rivastigmine in patients with severe hepatic impairment.
Low or High Body Weight
Because rivastigmine blood levels vary with weight [see CLINICAL PHARMACOLOGY], careful titration and monitoring should be performed in patients with low or high body weights. In patients with low body weight ( < 50 kg), monitor closely for toxicities (e.g., excessive nausea, vomiting), and consider reducing the maintenance dose to the 4.6 mg/24 hour Exelon Patch if such toxicities develop. In patients with body weight > 100 kg, consider the use of doses higher than 9.5 mg/24 hours.
Last reviewed on RxList: 7/30/2013
This monograph has been modified to include the generic and brand name in many instances.
Additional Exelon Patch Information
Exelon Patch - User Reviews
Report Problems to the Food and Drug Administration
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