DONEPEZIL HYDROCHLORIDE  (don-e'pe-zil)  Aricept, Aricept ODT Classifications: cholinergic, central acting; cholinesterase inhibitor; Therapeutic: antidementia Pregnancy Category: C
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Availability
5 mg, 10 mg tablets and orally disintegrating tablets
Action
In early stages of Alzheimer's disease, pathologic changes in neurons result in deficiency of acetylcholine. Aricept, a
cholinesterase inhibitor, presumably elevates acetylcholine concentration in the cerebral cortex by slowing degrading acetylcholine
released by remaining intact neurons.
Therapeutic Effect
Improves global function, cognition, and behavior of patients with mild to moderate Alzheimer's.
Uses
Mild, moderate or severe dementia of Alzheimer's type.
Unlabeled Uses
Vascular dementia, poststroke aphasia, memory improvement in multiple sclerosis patients.
Contraindications
Hypersensitivity to donepezil or tracine; pregnancy (category C), lactation; children; GI bleeding, jaundice.
Cautious Use
Anesthesia, sick sinus rhythm, AV block, bradycardia, cardiac arrhythmias, cardiac disease, hypotension; hyperthyroidism,
history of ulcers, abnormal liver function; patients with asthma or obstructive pulmonary disease, history of seizures, seizures,
urinary tract obstruction, intestinal obstruction; diarrhea, emesis, GI disease, renal failure, renal impairment, surgery.
Route & Dosage
Alzheimer's Disease Related Dementia (Mild to Moderate) Adult: PO 510 mg h.s.
Alzheimer's Disease Related Dementia (Severe) Adult: PO 10 mg q.d.
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Administration
Oral
- Give at h.s. just prior to going to bed.
- Increase dosage to 10 mg ONLY after 46 wk of therapy with the 5-mg dose.
- Store at 15°30° C (59°86° F).
Adverse Effects (≥1%)
Body as a Whole: Headache, fatigue.
CNS: Insomnia, dizziness,
depression, tremor, irritability, vertigo, ataxia.
CV: Syncope, hypertension, atrial fibrillation, hot flashes, hypotension.
GI: Nausea, diarrhea, vomiting, muscle cramps, anorexia, GI bleeding, bloating, fecal incontinence, epigastric pain.
Respiratory: Dyspnea.
Skin: Pruritus, sweating, urticaria.
Other: Ecchymoses, muscle cramps, dehydration, blurred vision, urinary incontinence, nocturia.
Interactions
Drug: Ketoconazole, quinidine may inhibit donepezil
metabolism;
carbamazepine, dexamethasone, phenobarbital, phenytoin, rifampin may increase donepezil elimination; donepezil may interfere with the action of
anticholinergic agents.
Pharmacokinetics
Absorption: Rapidly absorbed from GI tract.
Peak: 34 h.
Distribution: 96% protein bound.
Metabolism: Metabolized in the liver by CYP2D6 and CYP3A4 to at least 2 active metabolites.
Elimination: Primarily in urine.
Half-Life: 70 h.
Nursing Implications
Assessment & Drug Effects
- Monitor therapeutic effectiveness: Improvement as noted on the Alzheimer's Disease Assessment Scale.
- Monitor closely for S&S of GI ulceration and bleeding, especially with concurrent use of NSAIDS.
- Monitor carefully patients with a history of asthma or obstructive pulmonary disease.
- Monitor cardiovascular status; drug may have vagotonic effect on the heart, causing bradycardia, especially in presence
of conduction abnormalities.
Patient & Family Education
- Exercise caution. Fainting episodes related to slowing the heart rate may occur.
- Report immediately to physician any S&S of GI ulceration or bleeding (e.g., "coffee-grounds" emesis, tarry stools,
epigastric pain).