Product Information: Aricept (Donepezil)
Donepezil is an oral medication used to treat Alzheimer's disease. It belongs to a class of drugs called cholinesterase inhibitors that also includes tacrine (Cognex). Scientists believe that Alzheimer's disease may result from a deficiency in chemicals (neurotransmitters) used by nerves in the brain to communicate with one another. Donepezil inhibits acetylcholinesterase, an enzyme responsible for the destruction of one neurotransmitter, acetylcholine. This leads to increased concentrations of acetylcholine in the brain, and the increased concentrations are believed to be responsible for the improvement seen during treatment with Donepezil. Donepezil improves the symptoms but does not slow down the progression of Alzheimer's disease.
Aricept is available in 10 mg tablets. Tablets should be stored at room temperature, 15-30°C (59-86°F). Donepezil is generally taken once daily at night prior to retiring. Its absorption is not affected by food so that it may be taken with or without food.
Donepezil is used for the treatment of mild to moderate dementia of the Alzheimer's type.
Drugs with anti-cholinergic properties that can cross into the brain, such as atropine, benztropine (Cogentin), and trihexyphenidyl (Artane) counteract the effects of Donepezil and should be avoided during therapy with Donepezil.
Donepezil is metabolized (eliminated) by enzymes in the liver. The rate of metabolism of Donepezil may be increased by medications that increase the amounts of these enzymes, such as carbamazepine (Tegretol), dexamethasone (Decadron), phenobarbital, phenytoin (Dilantin), and rifampin (Rifadin). By increasing elimination, these drugs may reduce the effects of Donepezil.
Ketoconazole (Nizoral) has been shown to block the enzymes in the liver that metabolize Donepezil. Therefore, concurrent use of ketoconazole and Donepezil may result in increased concentrations of Donepezil in the body and possibly lead to Donepezil side effects. Quinidine (Quinidex, Quinaglute) also has been shown to inhibit the enzymes that metabolize Donepezil and may cause Donepezil side effects.
PREGNANCY: It is not known whether Donepezil is harmful to the foetus. Safe use during pregnancy has not been established.
NURSING MOTHERS: It is not known whether the Donepezil is secreted into breast milk or if breast-feeding while taking Donepezil is safe for the nursing infant.
SIDE EFFECTS: The most frequently reported side effects associated with Donepezil include headache, generalized pain, fatigue, dizziness, nausea, vomiting, diarrhoea, loss of appetite, weight loss, muscle cramping, joint pain, insomnia, and increased frequency of urination.
Tacrine (Cognex), another anticholinesterase medication used in the treatment of Alzheimer's disease, is associated with liver toxicity. Donepezil does not appear to be associated with liver toxicity.
ARICEPT / DONEPEZIL ®
Information for the User:
As in any case of overdose, general supportive measures should be utilized. Overdosage with cholinesterase inhibitors can result in cholinergic crisis characterized by severe nausea, vomiting, salivation, sweating, bradycardia, hypotension, respiratory depression, collapse and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Tertiary anticholinergics such as atropine may be used as an antidote for ARICEPT ® overdosage. Intravenous atropine sulfate titrated to effect is recommended: an initial dose of 1.0 to 2.0 mg IV with subsequent doses based upon clinical response. Atypical responses in blood pressure and heart rate have been reported with other cholinomimetics when co-administered with quaternary anticholinergics such as glycopyrrolate. It is not known whether ARICEPT ® and/or its metabolites can be removed by dialysis (hemodialysis, peritoneal dialysis, or hemofiltration). Dose-related signs of toxicity in animals included reduced spontaneous movement, prone position, staggering gait, lacrimation, clonic convulsions, depressed respiration, salivation, miosis, tremors, fasciculation and lower body surface temperature.
The higher dose of 10 mg did not provide a statistically significantly greater clinical benefit than 5 mg. There is a suggestion, however, based upon order of group mean scores and dose trend analyses of data from these clinical trials, that a daily dose of 10 mg of ARICEPT ® might provide additional benefit for some patients. Accordingly, whether or not to employ a dose of 10 mg is a matter of prescriber and patient preference.
Evidence from the controlled trials indicates that the 10 mg dose, with a one week titration, is likely to be associated with a higher incidence of cholinergic adverse events than the 5 mg dose. In open label trials using a 6 week titration, the frequency of these same adverse events was similar between the 5 mg and 10 mg dose groups. Therefore, because steady state is not achieved for 15 days and because the incidence of untoward effects may be influenced by the rate of dose escalation, treatment with a dose of 10 mg should not be contemplated until patients have been on a daily dose of 5 mg for 4 to 6 weeks.
ARICEPT ® should be taken in the evening, just prior to retiring. ARICEPT ® can be taken with or without food.
Please follow your doctor's instructions.
Many people take more than one medicine. Always check with the doctor before taking any other medicines with Aricept. These include: Prescriptions, Home remedies, Vitamins, Herbal remedies, Aspirin, Dietary supplements, Cold and allergy medicines, Other over the counter treatments
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