DONEPEZIL HYDROCHLORIDE

Donepezil hydrochloride is a reversible inhibitor of the enzyme acetylcholinesterase, known chemically as (±)-2, 3-dihydro-5, 6-dimethoxy-2-[[1-(phenylmethyl)-4-piperidinyl]methyl]-1 H -inden-1-one hydrochloride. Donepezil hydrochloride is commonly referred to in the pharmacological literature as E2020. It has a molecular formula of C 24 H 29 NO 3 HCl and a molecular weight of 415.96. Donepezil hydrochloride is a white crystalline powder and is freely soluble in chloroform, soluble in water and in glacial acetic acid, slightly soluble in ethanol and in acetonitrile, and practically insoluble in ethyl acetate and in n-hexane. Donepezil hydrochloride is available for oral administration in film-coated tablets containing 5 and 10 mg of donepezil hydrochloride. Inactive ingredients in 5 mg and 10 mg tablets are lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, magnesium stearate. The film coating contains talc, polyethylene glycol, polyvinyl alcohol and titanium dioxide. Additionally, the 10 mg tablet contains yellow iron oxide as a coloring agent. Donepezil hydrochloride orally disintegrating tablets USP are available for oral administration. Each Donepezil hydrochloride orally disintegrating tablet USP contains 5 or 10 mg of donepezil hydrochloride. Inactive ingredients are mannitol, silicified microcrystalline cellulose, low substituted hydroxypropyl cellulose, sucralose, orange flavor,sodium stearyl fumarate. Additionally, the 10 mg tablet contains iron oxide yellow as a coloring agent. Molecular Structure

Donepezil hydrochloride is an acetylcholinesterase inhibitor indicated for the treatment of dementia of the Alzheimer's type. Efficacy has been demonstrated in patients with mild, moderate, and severe Alzheimer's Disease ( 1 ) Donepezil hydrochloride is indicated for the treatment of dementia of the Alzheimer's type. Efficacy has been demonstrated in patients with mild, moderate, and severe Alzheimer's disease.

Mild to Moderate Alzheimer's Disease: 5 mg to 10 mg once daily ( 2.1 ) Moderate to Severe Alzheimer's Disease: 10 mg to 23 mg once daily ( 2.2 ) 2.1 Dosing in Mild to Moderate Alzheimer's Disease The recommended starting dosage of donepezil hydrochloride is 5 mg administered once per day in the evening, just prior to retiring. The maximum recommended dosage of donepezil hydrochloride in patients with mild to moderate Alzheimer's disease is 10 mg per day. A dose of 10 mg should not be administered until patients have been on a daily dose of 5 mg for 4 to 6 weeks 2.2 Dosing in Moderate to Severe Alzheimer's Disease The recommended starting dosage of donepezil hydrochloride is 5 mg administered once per day in the evening, just prior to retiring. The maximum recommended dosage of donepezil hydrochloride in patients with moderate to severe Alzheimer's disease is 23 mg per day. A dose of 10 mg should not be administered until patients have been on a daily dose of 5 mg for 4 to 6 weeks. A dose of 23 mg per day should not be administered until patients have been on a daily dose of 10 mg for at least 3 months. 2.3 Administration Information Donepezil hydrochloride tablet should be taken in the evening, just prior to retiring. Donepezil hydrochloride tablet can be taken with or without food. Allow donepezil hydrochloride ODT to dissolve on the tongue and follow with water.

Known hypersensitivity to donepezil hydrochloride or to piperidine derivatives ( 4 ) Donepezil hydrochloride is contraindicated in patients with known hypersensitivity to donepezil hydrochloride or to piperidine derivatives.

Most common adverse reactions in clinical studies of donepezil hydrochloride are nausea, diarrhea, insomnia, vomiting, muscle cramps, fatigue, and anorexia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Unichem Pharmaceuticals (USA) Inc. at 1-866-562-4616 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The following serious adverse reactions are described below and elsewhere in the labeling: Cardiovascular Conditions [see Warnings and Precautions ( 5.2 )] Nausea and Vomiting [see Warnings and Precautions ( 5.3 )] Peptic Ulcer Disease and GI Bleeding [see Warnings and Precautions ( 5.4 )] Weight Loss [see Warnings and Precautions ( 5.5 )] Genitourinary Conditions [see Warnings and Precautions ( 5.6 )] Neurological Conditions: Seizures [see Warnings and Precautions ( 5.7 )] Pulmonary Conditions [see Warnings and Precautions ( 5.8 )] 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Donepezil hydrochloride has been administered to over 1,700 individuals during clinical trials worldwide. Approximately 1200 of these patients have been treated for at least 3 months and more than 1,000 patients have been treated for at least 6 months. Controlled and uncontrolled trials in the United States included approximately 900 patients. In regards to the highest dose of 10 mg/day, this population includes 650 patients treated for 3 months, 475 patients treated for 6 months, and 116 patients treated for over 1 year. The range of patient exposure is from 1 to 1,214 days. Mild to Moderate Alzheimer's Disease Adverse Reactions Leading to Discontinuation The rates of discontinuation from controlled clinical trials of donepezil hydrochloride due to adverse reactions for the donepezil hydrochloride 5 mg/day treatment groups were comparable to those of placebo treatment groups at approximately 5%. The rate of discontinuation of patients who received 7-day escalations from 5 mg/day to 10 mg/day was higher at 13%. The most common adverse reactions leading to discontinuation, defined as those occurring in at least 2% of patients and at twice or more the incidence seen in placebo patients, are shown in Table 1. Table 1 . Most Common Adverse Reactions Leading to Discontinuation in Patients with Mild to Moderate Alzheimer’s Disease Adverse Reaction Placebo ( n = 355 ) % 5 mg / day Donepezil hydrochloride ( n = 350 ) % 10 mg / day Donepezil hydrochloride ( n = 315 ) % Nausea 1 1 3 Diarrhea 0 <1 3 Vomiting <1 <1 2 Most Common Adverse Reactions The most common adverse reactions, defined as those occurring at a frequency of at least 5% in patients receiving 10 mg/day and twice the placebo rate, are largely predicted by donepezil hydrochloride's cholinomimetic effects. These include nausea, diarrhea, insomnia, vomiting, muscle cramp, fatigue, and anorexia. These adverse reactions were often transient, resolving during continued donepezil hydrochloride treatment without the need for dose modification. There is evidence to suggest that the frequency of these common adverse reactions may be affected by the rate of titration. An open-label study was conducted with 269 patients who received placebo in the 15-and 30-week studies. These patients were titrated to a dose of 10 mg/day over a 6-week period. The rates of common adverse reactions were lower than those seen in patients titrated to 10 mg/day over one week in the controlled clinical trials and were comparable to those seen in patients on 5 mg/day. See Table 2 for a comparison of the most common adverse reactions following one and six week titration regimens. Table 2. Comparison of Rates of Adverse Reactions in Mild to Moderate Patients Titrated to 10 mg/day over 1 and 6 Weeks No titration One week titration Six week titration Adverse Reaction Placebo (n=315) % 5 mg/day (n=311) % 10 mg/day (n=315) % 10 mg/day (n=269) % Nausea 6 5 19 6 Diarrhea 5 8 15 9 Insomnia 6 6 14 6 Fatigue 3 4 8 3 Vomiting 3 3 8 5 Muscle cramps 2 6 8 3 Anorexia 2 3 7 3 Table 3 lists adverse reactions that occurred in at least 2% of patients in pooled placebo-controlled trials who received either donepezil hydrochloride 5 mg or 10 mg and for which the rate of occurrence was greater for patients treated with donepezil hydrochloride than with placebo. In general, adverse reactions occurred more frequently in female patients and with advancing age. Table 3 . Adverse Reactions in Pooled Placebo - Controlled Clinical Trials in Mild toModerate Alzheimer’s Disease Adverse Reaction Placebo ( n = 355 ) % Donepezil hydrochloride ( n = 747 ) % Percent of Patients with any Adverse Reaction 72 74 Nausea 6 11 Diarrhea 5 10 Headache 9 10 Insomnia 6 9 Pain, various locations 8 9 Dizziness 6 8 Accident 6 7 Muscle Cramps 2 6 Fatigue 3 5 Vomiting 3 5 Anorexia 2 4 Ecchymosis 3 4 Abnormal Dreams 0 3 Depression <1 3 Weight Loss 1 3 Arthritis 1 2 Frequent Urination 1 2 Somnolence <1 2 Syncope 1 2 Severe Alzheimer's Disease (Donepezil hydrochloride 5 mg/day and 10 mg/day) Donepezil hydrochloride has been administered to over 600 patients with severe Alzheimer's disease during clinical trials of at least 6 months duration, including three double-blind, placebo-controlled trials, two of which had an open label extension. Adverse Reactions Leading to Discontinuation The rates of discontinuation from controlled clinical trials of donepezil hydrochloride due to adverse reactions for the donepezil hydrochloride patients were approximately 12% compared to 7% for placebo patients. The most common adverse reactions leading to discontinuation, defined as those occurring in at least 2% of donepezil hydrochloride patients and at twice or more the incidence seen in placebo, were anorexia (2% vs. 1% placebo), nausea (2% vs. <1% placebo), diarrhea (2% vs. 0% placebo), and urinary tract infection (2% vs. 1% placebo). Most Common Adverse Reactions The most common adverse reactions, defined as those occurring at a frequency of at least 5% in patients receiving donepezil hydrochloride and at twice or more the placebo rate, are largely predicted by donepezil hydrochloride's cholinomimetic effects. These include diarrhea, anorexia, vomiting, nausea, and ecchymosis. These adverse reactions were often transient, resolving during continued donepezil hydrochloride treatment without the need for dose modification. Table 4 lists adverse reactions that occurred in at least 2% of patients in pooled placebo-controlled trials who received donepezil hydrochloride 5 mg or 10 mg and for which the rate of occurrence was greater for patients treated with donepezil hydrochloride than with placebo. Table 4. Adverse Reactions in Pooled Controlled Clinical Trials in Severe Alzheimer's Disease Body Systems/Adverse Reaction Placebo (n=392) % Donepezil hydrochloride (n=501) % Percent of Patients with any Adverse Reaction 73 81 Accident 12 13 Infection 9 11 Diarrhea 4 10 Anorexia 4 8 Vomiting 4 8 Nausea 4 8 Insomnia 2 6 Ecchymosis 4 5 Headache 2 5 Hypertension 3 4 Pain 2 3 Back Pain 2 3 Eczema 2 3 Hallucinations 2 3 Hostility 1 3 Increase in Creatine Phosphokinase 2 3 Nervousness 1 3 Fever 2 3 Chest Pain 1 2 Confusion <1 2 Dehydration 1 2 Depression 1 2 Dizziness 1 2 Emotional Lability 1 2 Hemorrhage 1 2 Hyperlipemia 1 2 Personality Disorder <1 2 Somnolence 1 2 Syncope 1 2 Urinary Incontinence 1 2 Moderate to Severe Alzheimer's Disease (Donepezil hydrochloride 23 mg/day) Donepezil hydrochloride 23 mg/day has been administered to over 1300 individuals globally in clinical trials. Approximately 1050 of these patients have been treated for at least three months and more than 950 patients have been treated for at least six months. The range of patient exposure was from 1 to over 500 days. Adverse Reactions Leading to Discontinuation The rate of discontinuation from a controlled clinical trial of donepezil hydrochloride 23 mg/day due to adverse reactions was higher (19%) than for the 10 mg/day treatment group (8%). The most common adverse reactions leading to discontinuation, defined as those occurring in at least 1% of patients and greater than those occurring with 10 mg/day are shown in Table 5. Table 5 . Most Common Adverse Reactions Leading to Discontinuation in Patients with Moderate to Severe Alzeimer's Disease Adverse Reaction 23 mg / day Donepezil hydrochloride ( n = 963 ) % 10 mg / day Donepezil Hydrochloride ( n = 471 ) % Vomiting 3 0 Diarrhea 2 0 Nausea 2 0 Dizziness 1 0 The majority of discontinuations due to adverse reactions in the 23 mg group occurred during the first month of treatment. Most Common Adverse Reactions with donepezil hydrochloride 23 mg/day The most common adverse reactions, defined as those occurring at a frequency of at least 5%, include nausea, diarrhea, vomiting, and anorexia. Table 6 lists adverse reactions that occurred in at least 2% of patients who received 23 mg/day of donepezil hydrochloride and at a higher frequency than those receiving 10 mg/day of donepezil hydrochloride in a controlled clinical trial that compared the two doses. In this study, there were no important differences in the type of adverse reactions in patients taking donepezil hydrochloride with or without memantine. Table 6. Adverse Reactions in a Controlled Clinical Trial in Moderate to Severe Alzheimer's Disease Adverse Reaction 23 mg/day Donepezil hydrochloride (n=963) % 10 mg/day Donepezil hydrochloride (n=471) % Percent of Patients with any Adverse Reaction 74 64 Nausea 12 3 Vomiting 9 3 Diarrhea 8 5 Anorexia 5 2 Dizziness 5 3 Weight Loss 5 3 Headache 4 3 Insomnia 3 2 Urinary Incontinence 3 1 Asthenia 2 1 Contusion 2 0 Fatigue 2 1 Somnolence 2 1 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of donepezil hydrochloride. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Abdominal pain, agitation, aggression, cholecystitis, confusion, convulsions, hallucinations, heart block (all types), hemolytic anemia, hepatitis, hyponatremia, neuroleptic malignant syndrome, pancreatitis, rash, rhabdomyolysis, QTc prolongation, and torsade de pointes.

Cholinesterase inhibitors have the potential to interfere with the activity of anticholinergic medications ( 7.1 ) A synergistic effect may be expected with concomitant administration of succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists ( 7.2 ) 7.1 Use with Anticholinergics Because of their mechanism of action, cholinesterase inhibitors have the potential to interfere with the activity of anticholinergic medications. 7.2 Use with Cholinomimetics and Other Cholinesterase Inhibitors A synergistic effect may be expected when cholinesterase inhibitors are given concurrently with succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists such as bethanechol.