168 HR donepezil 0.417 MG/HR Transdermal System

INDICATIONS AND USAGE Memantine and donepezil hydrochlorides extended-release capsules are indicated for the treatment of moderate to severe dementia of the Alzheimer’s type in patients stabilized on 10 mg of donepezil hydrochloride once daily. Memantine and donepezil hydrochlorides extended-release capsules are a combination of memantine hydrochloride, an NMDA receptor antagonist, and donepezil hydrochloride, an acetylcholinesterase inhibitor, indicated for the treatment of moderate to severe dementia of the Alzheimer’s type in patients stabilized on 10 mg of donepezil hydrochloride once daily. ( 1 )

DOSAGE AND ADMINISTRATION • For patients on donepezil hydrochloride 10 mg only, the recommended starting dose of memantine and donepezil hydrochlorides extended-release capsules is 7 mg/10 mg, taken once daily in the evening. The dose should be increased in 7 mg increment to the recommended maintenance dose of 28 mg /10 mg. the minimum recommended interval between dose increases is one week. ( 2.1 ) • Patients on memantine hydrochloride (10 mg twice daily or 28 mg extended-release once daily) and donepezil hydrochloride 10 mg once daily can be switched to memantine and donepezil hydrochlorides extended-release capsules 28 mg/10 mg, taken once daily in the evening ( 2.1 ) • Memantine and donepezil hydrochlorides extended-release capsules can be taken with or without food, whole or sprinkled on applesauce; do not divide, chew, or crush ( 2.2 ) • Severe renal impairment: the recommended maintenance dose for memantine and donepezil hydrochlorides extended-release capsules is 14 mg/10 mg once daily in the evening. ( 2.3 ) 2.1 Recommended Dosing The recommended dose of memantine and donepezil hydrochlorides extended-release capsules is 28 mg/10 mg once daily. For patients stabilized on donepezil and not currently on memantine: For patients stabilized on donepezil hydrochloride 10 mg and not currently on memantine hydrochloride, the recommended starting dose of memantine and donepezil hydrochlorides extended-release capsules is 7 mg/10 mg, taken once a day in the evening. The dose should be increased in 7 mg increments of the memantine hydrochloride component to the recommended maintenance dose of 28 mg/10 mg once daily. The minimum recommended interval between dose increases is one week. The dose should only be increased if the previous dose has been well tolerated. The maximum dose is 28 mg /10 mg once daily. For patients stabilized on both donepezil and memantine: Patients stabilized on memantine hydrochloride (10 mg twice daily or 28 mg extended-release once daily) and donepezil hydrochloride 10 mg once daily can be switched to memantine and donepezil hydrochlorides extended-release capsules 28 mg/10 mg, taken once a day in the evening. Patients should start memantine and donepezil hydrochlorides extended-release capsules the day following the last dose of memantine hydrochloride and donepezil hydrochloride administered separately. If a patient misses a single dose of memantine and donepezil hydrochlorides extended-release capsules, the next dose should be taken as scheduled, without doubling up the dose. 2.2 Administration Information Memantine and donepezil hydrochlorides extended-release capsules can be taken with or without food. Memantine and donepezil hydrochlorides extended-release capsules can be taken intact or may be opened, sprinkled on applesauce, and swallowed without chewing. The entire contents of each memantine and donepezil hydrochlorides extended-release capsules should be consumed; the dose should not be divided. Except when opened and sprinkled on applesauce, as described above, memantine and donepezil hydrochlorides extended-release capsules should be swallowed whole. Memantine and donepezil hydrochlorides extended-release capsules should not be divided, chewed, or crushed. 2.3 Dosing in Patients with Severe Renal Impairment For patients stabilized on donepezil and not currently on memantine: For patients with severe renal impairment (creatinine clearance 5-29 mL/min, based on the Cockcroft-Gault equation) stabilized on donepezil hydrochloride 10 mg once daily and not currently on memantine hydrochloride, the recommended starting dose of memantine and donepezil hydrochlorides extended-release capsules is 7 mg/10 mg taken once a day in the evening. The dose should be increased to the recommended maintenance dose of 14 mg/10 mg once daily in the evening after a minimum of one week [ see Use in Specific Populations (8.6) ]. For patients stabilized on both donepezil and memantine: Patients with severe renal impairment, stabilized on memantine hydrochloride (5 mg twice daily or 14 mg extended-release once daily) and donepezil hydrochloride 10 mg once daily, can be switched to memantine and donepezil hydrochlorides extended-release capsules 14 mg/10 mg, taken once daily in the evening.

WARNINGS AND PRECAUTIONS Cholinesterase inhibitors are likely to exaggerate succinylcholine-type muscle relaxation during anesthesia ( 5.1 ) Cholinesterase inhibitors may have vagotonic effects on the sinoatrial and atrioventricular nodes manifesting as bradycardia or heart block ( 5.2 ) Donepezil hydrochloride tablets can cause vomiting. Patients should be observed closely at initiation of treatment and after dose increases ( 5.3 ) Patients should be monitored closely for symptoms of active or occult gastrointestinal (GI) bleeding, especially those at increased risk for developing ulcers ( 5.4 ) The use of donepezil hydrochloride tablets in a dose of 23 mg once daily is associated with weight loss ( 5.5 ) Cholinomimetics may cause bladder outflow obstructions ( 5.6 ) Cholinomimetics are believed to have some potential to cause generalized convulsions ( 5.7 ) Cholinesterase inhibitors should be prescribed with care to patients with a history of asthma or obstructive pulmonary disease ( 5.8 ) 5.1 Anesthesia Donepezil hydrochloride tablets, as a cholinesterase inhibitor, are likely to exaggerate succinylcholine-type muscle relaxation during anesthesia. 5.2 Cardiovascular Conditions Because of their pharmacological action, cholinesterase inhibitors may have vagotonic effects on the sinoatrial and atrioventricular nodes. This effect may manifest as bradycardia or heart block in patients both with and without known underlying cardiac conduction abnormalities. Syncopal episodes have been reported in association with the use of donepezil hydrochloride tablets. 5.3 Nausea and Vomiting Donepezil hydrochloride tablets, as a predictable consequence of its pharmacological properties, have been shown to produce diarrhea, nausea, and vomiting. These effects, when they occur, appear more frequently with the 10 mg/day dose than with the 5 mg/day dose, and more frequently with the 23 mg dose than with the 10 mg dose. Specifically, in a controlled trial that compared a dose of 23 mg/day to 10 mg/day in patients who had been treated with donepezil 10 mg/day for at least three months, the incidence of nausea in the 23 mg group was markedly greater than in the patients who continued on 10 mg/day (11.8% vs. 3.4%, respectively), and the incidence of vomiting in the 23 mg group was markedly greater than in the 10 mg group (9.2% vs. 2.5%, respectively). The percent of patients who discontinued treatment due to vomiting in the 23 mg group was markedly higher than in the 10 mg group (2.9% vs. 0.4%, respectively). Although in most cases, these effects have been transient, sometimes lasting one to three weeks, and have resolved during continued use of donepezil hydrochloride tablets, patients should be observed closely at the initiation of treatment and after dose increases. 5.4 Peptic Ulcer Disease and GI Bleeding Through their primary action, cholinesterase inhibitors may be expected to increase gastric acid secretion due to increased cholinergic activity. Therefore, patients should be monitored closely 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 donepezil hydrochloride tablets in a dose of 5 mg/day to 10 mg/day have shown no increase, relative to placebo, in the incidence of either peptic ulcer disease or gastrointestinal bleeding. Results of a controlled clinical study with 23 mg/day showed an increase, relative to 10 mg/day, in the incidence of peptic ulcer disease (0.4% vs. 0.2%) and gastrointestinal bleeding from any site (1.1% vs. 0.6%). 5.5 Weight Loss Weight loss was reported as an adverse reaction in 4.7% of patients assigned to donepezil hydrochloride tablets in a dose of 23 mg/day compared to 2.5% of patients assigned to 10 mg/day. Compared to their baseline weights, 8.4% of patients taking 23 mg/day were found to have a weight decrease of ≥ 7% by the end of the study, while 4.9% of patients taking 10 mg/day were found to have weight loss of ≥ 7% at the end of the study. 5.6 Genitourinary Conditions Although not observed in clinical trials of donepezil hydrochloride tablets, cholinomimetics may cause bladder outflow obstruction. 5.7 Neurological Conditions: Seizures Cholinomimetics are believed to have some potential to cause generalized convulsions. However, seizure activity also may be a manifestation of Alzheimer’s disease. 5.8 Pulmonary Conditions Because of their cholinomimetic actions, cholinesterase inhibitors should be prescribed with care to patients with a history of asthma or obstructive pulmonary disease. 5.1 Anesthesia Donepezil hydrochloride tablets, as a cholinesterase inhibitor, are likely to exaggerate succinylcholine-type muscle relaxation during anesthesia. 5.2 Cardiovascular Conditions Because of their pharmacological action, cholinesterase inhibitors may have vagotonic effects on the sinoatrial and atrioventricular nodes. This effect may manifest as bradycardia or heart block in patients both with and without known underlying cardiac conduction abnormalities. Syncopal episodes have been reported in association with the use of donepezil hydrochloride tablets. 5.3 Nausea and Vomiting Donepezil hydrochloride tablets, as a predictable consequence of its pharmacological properties, have been shown to produce diarrhea, nausea, and vomiting. These effects, when they occur, appear more frequently with the 10 mg/day dose than with the 5 mg/day dose, and more frequently with the 23 mg dose than with the 10 mg dose. Specifically, in a controlled trial that compared a dose of 23 mg/day to 10 mg/day in patients who had been treated with donepezil 10 mg/day for at least three months, the incidence of nausea in the 23 mg group was markedly greater than in the patients who continued on 10 mg/day (11.8% vs. 3.4%, respectively), and the incidence of vomiting in the 23 mg group was markedly greater than in the 10 mg group (9.2% vs. 2.5%, respectively). The percent of patients who discontinued treatment due to vomiting in the 23 mg group was markedly higher than in the 10 mg group (2.9% vs. 0.4%, respectively). Although in most cases, these effects have been transient, sometimes lasting one to three weeks, and have resolved during continued use of donepezil hydrochloride tablets, patients should be observed closely at the initiation of treatment and after dose increases. 5.4 Peptic Ulcer Disease and GI Bleeding Through their primary action, cholinesterase inhibitors may be expected to increase gastric acid secretion due to increased cholinergic activity. Therefore, patients should be monitored closely 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 donepezil hydrochloride tablets in a dose of 5 mg/day to 10 mg/day have shown no increase, relative to placebo, in the incidence of either peptic ulcer disease or gastrointestinal bleeding. Results of a controlled clinical study with 23 mg/day showed an increase, relative to 10 mg/day, in the incidence of peptic ulcer disease (0.4% vs. 0.2%) and gastrointestinal bleeding from any site (1.1% vs. 0.6%). 5.5 Weight Loss Weight loss was reported as an adverse reaction in 4.7% of patients assigned to donepezil hydrochloride tablets in a dose of 23 mg/day compared to 2.5% of patients assigned to 10 mg/day. Compared to their baseline weights, 8.4% of patients taking 23 mg/day were found to have a weight decrease of ≥ 7% by the end of the study, while 4.9% of patients taking 10 mg/day were found to have weight loss of ≥ 7% at the end of the study. 5.6 Genitourinary Conditions Although not observed in clinical trials of donepezil hydrochloride tablets, cholinomimetics may cause bladder outflow obstruction. 5.7

CONTRAINDICATIONS Memantine and donepezil hydrochlorides extended-release capsules are contraindicated in patients with known hypersensitivity to memantine hydrochloride, donepezil hydrochloride, piperidine derivatives, or to any excipients used in the formulation. Memantine and donepezil hydrochlorides extended-release capsules are contraindicated in patients with known hypersensitivity to memantine hydrochloride, donepezil hydrochloride, piperidine derivatives, or to any excipients used in the formulation. ( 4 )

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Current theories on the pathogenesis of the cognitive signs and symptoms of Alzheimer’s disease attribute some of them to a deficiency of cholinergic neurotransmission. Donepezil hydrochloride is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by acetylcholinesterase. There is no evidence that donepezil alters the course of the underlying dementing process. 12.3 Pharmacokinetics Pharmacokinetics of donepezil are linear over a dose range of 1-10 mg given once daily. The rate and extent of absorption of donepezil hydrochloride tablets are not influenced by food. Based on population pharmacokinetic analysis of plasma donepezil concentrations measured in patients with Alzheimer’s disease, following oral dosing, peak plasma concentration is achieved for donepezil hydrochloride 23 mg tablets in approximately 8 hours, compared with 3 hours for donepezil hydrochloride 10 mg tablets. Peak plasma concentrations were about 2-fold higher for donepezil hydrochloride 23 mg tablets than donepezil hydrochloride 10 mg tablets. Donepezil hydrochloride ODT 5 mg and 10 mg are bioequivalent to donepezil hydrochloride 5 mg and 10 mg tablets, respectively. A food effect study has not been conducted with donepezil hydrochloride ODT; however, the effect of food with donepezil hydrochloride ODT is expected to be minimal. Donepezil hydrochloride ODT can be taken without regard to meals. The elimination half life of donepezil is about 70 hours, and the mean apparent plasma clearance (Cl/F) is 0.13-0.19 L/hr/kg. Following multiple dose administration, donepezil accumulates in plasma by 4-7 fold, and steady state is reached within 15 days. The steady state volume of distribution is 12-16 L/kg. Donepezil is approximately 96% bound to human plasma proteins, mainly to albumins (about 75%) and alpha1 -acid glycoprotein (about 21%) over the concentration range of 2-1000 ng/mL. Donepezil is both excreted in the urine intact and extensively metabolized to four major metabolites, two of which are known to be active, and a number of minor metabolites, not all of which have been identified. Donepezil is metabolized by CYP 450 isoenzymes 2D6 and 3A4 and undergoes glucuronidation. Following administration of 14 C-labeled donepezil, plasma radioactivity, expressed as a percent of the administered dose, was present primarily as intact donepezil (53%) and as 6-O-desmethyl donepezil (11%), which has been reported to inhibit AChE to the same extent as donepezil in vitro and was found in plasma at concentrations equal to about 20% of donepezil. Approximately 57% and 15% of the total radioactivity was recovered in urine and feces, respectively, over a period of 10 days, while 28% remained unrecovered, with about 17% of the donepezil dose recovered in the urine as unchanged drug. Examination of the effect of CYP2D6 genotype in Alzheimer’s patients showed differences in clearance values among CYP2D6 genotype subgroups. When compared to the extensive metabolizers, poor metabolizers had a 31.5% slower clearance and ultra-rapid metabolizers had a 24% faster clearance. Hepatic Disease In a study of 10 patients with stable alcoholic cirrhosis, the clearance of donepezil hydrochloride tablets was decreased by 20% relative to 10 healthy age-and sex-matched subjects. Renal Disease In a study of 11 patients with moderate to severe renal impairment (ClC < 18 mL/min/1.73 m 2 ) the clearance of donepezil hydrochloride tablets did not differ from 11 age-and sex-matched healthy subjects. Age No formal pharmacokinetic study was conducted to examine age-related differences in the pharmacokinetics of donepezil hydrochloride tablets. Population pharmacokinetic analysis suggested that the clearance of donepezil in patients decreases with increasing age. When compared with 65-year old, subjects, 90-year old subjects have a 17% decrease in clearance, while 40-year old subjects have a 33% increase in clearance. The effect of age on donepezil clearance may not be clinically significant. Gender and Race No specific pharmacokinetic study was conducted to investigate the effects of gender and race on the disposition of donepezil hydrochloride tablets. However, retrospective pharmacokinetic analysis and population pharmacokinetic analysis of plasma donepezil concentrations measured in patients with Alzheimer’s disease indicates that gender and race (Japanese and Caucasians) did not affect the clearance of donepezil hydrochloride tablets to an important degree. Body Weight There was a relationship noted between body weight and clearance. Over the range of body weight from 50 kg to 110 kg, clearance increased from 7.77 L/h to 14.04 L/h, with a value of 10 L/hr for 70 kg individuals. Drug Interactions Effect of Donepezil Hydrochloride Tablets on the Metabolism of Other Drugs No in vivo clinical trials have investigated the effect of donepezil hydrochloride tablets on the clearance of drugs metabolized by CYP 3A4 (e.g., cisapride, terfenadine) or by CYP 2D6 (e.g., imipramine). However, in vitro studies show a low rate of binding to these enzymes (mean Ki about 50-130 μM), that, given the therapeutic plasma concentrations of donepezil (164 nM), indicates little likelihood of interference. Based on in vitro studies, donepezil shows little or no evidence of direct inhibition of CYP2B6, CYP2C8, and CYP2C19 at clinically relevant concentrations. Whether donepezil hydrochloride tablets have any potential for enzyme induction is not known. Formal pharmacokinetic studies evaluated the potential of donepezil hydrochloride tablets for interaction with theophylline, cimetidine, warfarin, digoxin, and ketoconazole. No effects of donepezil hydrochloride tablets on the pharmacokinetics of these drugs were observed. Effect of Other Drugs on the Metabolism of Donepezil Hydrochloride Tablets Ketoconazole and quinidine, strong inhibitors of CYP450 3A and 2D6, respectively, inhibit donepezil metabolism in vitro . Whether there is a clinical effect of quinidine is not known. Population pharmacokinetic analysis showed that in the presence of concomitant CYP2D6 inhibitors donepezil AUC was increased by approximately 17% to 20% in Alzheimer’s disease patients taking donepezil hydrochloride tablets 10 and 23 mg. This represented an average effect of weak, moderate, and strong CYP2D6 inhibitors. In a 7-day crossover study in 18 healthy volunteers, ketoconazole (200 mg q.d.) increased mean donepezil (5 mg q.d.) concentrations (AUC0-24 and Cmax) by 36%. The clinical relevance of this increase in concentration is unknown. Inducers of CYP 3A (e.g., phenytoin, carbamazepine, dexamethasone, rifampin, and phenobarbital) could increase the rate of elimination of donepezil hydrochloride tablets. Formal pharmacokinetic studies demonstrated that the metabolism of donepezil hydrochloride tablets is not significantly affected by concurrent administration of digoxin or cimetidine. An in vitro study showed that donepezil was not a substrate of P-glycoprotein. Drugs Highly Bound to Plasma Proteins Drug displacement studies have been performed in vitro between this highly bound drug (96%) and other drugs such as furosemide, digoxin, and warfarin. Donepezil hydrochloride tablets at concentrations of 0.3-10 micrograms/mL did not affect the binding of furosemide (5 micrograms/mL), digoxin (2 ng/mL), and warfarin (3 micrograms/mL) to human albumin. Similarly, the binding of donepezil hydrochloride tablets to human albumin was not affected by furosemide, digoxin, and warfarin. 12.1 Mechanism of Action Current theories on the pathogenesis of the cognitive signs and symptoms of Alzheimer’s disease attribute some of them to a deficiency of cholinergic neurotransmission. Donepezil hydrochloride is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accom