memantine hydrochloride and donepezil hydrochloride

1 INDICATIONS AND USAGE Memantine and donepezil hydrochlorides extended-release capsules is 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 is 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 )

2 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 increments 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 impairmen …

3 DOSAGE FORMS AND STRENGTHS Extended-Release Capsules: 14 mg memantine hydrochloride and 10 mg donepezil hydrochloride: dark green opaque capsules, printed with "LPMD" on the cap and "14/10" on the body in black ink. 28 mg memantine hydrochloride and 10 mg donepezil hydrochloride: blue opaque capsules, printed with "LPMD" on the cap and "28/10" on the body in black ink. -Extended-Release Capsules: 14 mg memantine hydrochloride and 10 mg donepezil hydrochloride ( 3 ) 28 mg memantine hydrochloride and 10 mg donepezil hydrochloride ( 3 )

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

6 ADVERSE REACTIONS The following serious adverse reactions are discussed below and elsewhere in the labeling. Cardiovascular Conditions [see Warnings and Precautions ( 5.2 )] Peptic Ulcer Disease and Gastrointestinal Bleeding [see Warnings and Precautions ( 5.3 )] Nausea and Vomiting [see Warnings and Precautions ( 5.4 )] Genitourinary Conditions [see Warnings and Precautions ( 5.5 )] Seizures [see Warnings and Precautions ( 5.6 )] Pulmonary Conditions [see Warnings and Precautions ( 5.7 )] The most common adverse reactions, occurring at a frequency of at least 5% and greater than placebo with memantine hydrochloride extended-release 28 mg/day, were headache, diarrhea, and dizziness. ( 6.1 ) The most common adverse reactions, occurring at a frequency of at least 5% in patients receiving donepezil hydrochloride and at twice or more the placebo rate, include diarrhea, anorexia, vomiting, nausea, and ecchymosis. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Xiamen LP Pharmaceutical Co., Ltd. at 1-877-676-0778 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 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. Memantine Hydrochloride Memantine hydrochloride extended-release was evaluated in a double-blind, placebo-controlled trial in 676 patients with moderate to severe dementia of the Alzheimer's type (341 patients treated with memantine 28 mg/day dose and 335 patients treated with placebo) for a treatment period up to 24 weeks. Of the patients randomized, 236 treated with memantine 28 mg/day and 227 treated with placebo were on a stable dose of donepezil for 3 months prior to screening. Adverse Reactions Leading to Discontinuation with Memantine Hydrochloride In the placebo-controlled clinical trial of memantine hydrochloride extended-release, the proportion of patients in the memantine hydrochloride extended-release 28 mg/day dose group and in the placebo group who discontinued treatment due to adverse reactions was 10% and 6%, respectively. The most common adverse reaction in the memantine hydrochloride extended-release treated group that led to treatment discontinuation was dizziness, at a rate of 1.5%. Most Common Adverse Reactions with Memantine Hydrochloride The most common adverse reactions with memantine hydrochloride extended-release in patients with moderate to severe Alzheimer's disease, defined as those occurring at a frequency of at least 5% in the memantine hydrochloride extended-release group and at a higher frequency than placebo, were headache, diarrhea, and dizziness. Table 1 lists adverse reactions that occurred at an incidence of ≥ 2% in the memantine hydrochloride extended-release treated group and occurred at a rate greater than placebo. Table 1: Adverse reactions with memantine hydrochloride extended-release in patients with moderate to severe Alzheimer's disease Adverse Reaction Placebo (n = 335) % Memantine hydrochloride extended-release 28 mg (n = 341) % Gastrointestinal Disorders Diarrhea 4 5 Constipation 1 3 Abdominal pain 1 2 Vomiting 1 2 Infections and Infestations Influenza 3 4 Investigations Increased weight 1 3 Musculoskeletal and Connective Tissue Disorders Back pain 1 3 Nervous System Disorders Headache 5 6 Dizziness 1 5 Somnolence 1 3 Psychiatric Disorders Anxiety 3 4 Depression 1 3 Aggression 1 2 Renal and Urinary Disorders Urinary incontinence 1 2 Vascular Disorders Hypertension 2 4 Hypotension 1 2 Donepezil hydrochloride Adverse Reactions Leading to Discontinuation with Donepezil Hydrochloride In controlled clinical trials of donepezil hydrochloride, the rate of discontinuation due to adverse reactions for patients treated with donepezil hydrochloride was approximately 12%, compared to 7% for patients treated with placebo. The most common adv …

7 DRUG INTERACTIONS Combined use with NMDA antagonists: use with caution. ( 7.2 ) Memantine and donepezil hydrochlorides extended-release capsules may interfere with anticholinergic medications. ( 7.4 ) Concomitant administration of succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists may lead to synergistic effect. ( 7.5 ) 7.1 Use of Memantine with Drugs That Make the Urine Alkaline The clearance of memantine was reduced by about 80% under alkaline urine conditions at pH 8. Therefore, alterations of urine pH towards the alkaline condition may lead to an accumulation of the drug with a possible increase in adverse reactions. Urine pH is altered by diet, drugs (e.g., carbonic anhydrase inhibitors, sodium bicarbonate) and clinical state of the patient (e.g., renal tubular acidosis or severe infections of the urinary tract). Hence, memantine should be used with caution under these conditions. 7.2 Use of Memantine with Other N-methyl-D-aspartate (NMDA) Antagonists The combined use of memantine hydrochloride with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated and such use should be approached with caution. 7.3 Effect of Other Drugs on the Metabolism of Donepezil Inhibitors of CYP3A4 (e.g., ketoconazole) and CYP2D6 (e.g., quinidine), inhibit donepezil metabolism in vitro . Whether there is a clinical effect of quinidine is not known. Inducers of CYP3A4 (e.g., phenytoin, carbamazepine, dexamethasone, rifampin, and phenobarbital) could increase the rate of elimination of donepezil. 7.4 Use of Donepezil with Anticholinergics Because of their mechanism of action, cholinesterase inhibitors, including donepezil hydrochloride, have the potential to interfere with the activity of anticholinergic medications. 7.5 Use of Donepezil with Cholinomimetics and Other Cholinesterase Inhibitors A synergistic effect may be expected when cholinesterase inhibitors, including donepezil hydrochloride, are given concurrently with succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists such as bethanechol.

8 USE IN SPECIFIC POPULATIONS 8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of memantine and donepezil hydrochlorides extended-release capsules or its active ingredients (memantine hydrochloride and donepezil hydrochloride) in pregnant women. Adverse developmental effects (mortality and decreased body weight and skeletal ossification) were observed in the offspring of rats administered memantine or donepezil during pregnancy at doses associated with minimal maternal toxicity. These doses are higher than those used in humans at the recommended daily dose of memantine and donepezil hydrochlorides extended-release capsules [see Data ] . In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. Data Animal Data Memantine Hydrochloride Oral administration of memantine (2, 6, or 18 mg/kg/day) to rats during the period of organogenesis resulted in decreased skeletal ossification in fetuses at the highest dose tested. The higher no-effect dose for adverse developmental effects (6 mg/kg) is 2 times the dose of memantine at the recommended human daily dose (RHD) of memantine and donepezil hydrochlorides extended-release capsules (28 mg memantine/10 mg donepezil) on a body surface area (mg/m 2 ) basis. Oral administration of memantine to rabbits (3, 10, or 30 mg/kg/day) during the period of organogenesis resulted in no adverse developmental effects. The highest dose tested is approximately 20 times the dose of memantine at the RHD of memantine and donepezil hydrochlorides extended-release capsules on a mg/m 2 basis. In rats, memantine (2, 6, or 18 mg/kg/day) was administered orally prior to and throughout mating and, in females, through the period of organogenesis or continuing throughout lactation to weaning. Decreased skeletal ossification in fetuses and decreased body weight in pups were observed at the highest dose tested. The higher no-effect dose for adverse developmental effects (6 mg/kg/day) is 2 times the dose of memantine at the RHD of memantine and donepezil hydrochlorides extended-release capsules on a mg/m 2 basis. Oral administration of memantine (2, 6, or 18 mg/kg/day) to rats from late gestation throughout lactation to weaning, resulted in decreased pup weights at the highest dose tested. The higher no-effect dose (6 mg/kg/day) is approximately 2 times the dose of memantine at the RHD of memantine and donepezil hydrochlorides extended-release capsules on a mg/m 2 basis. Donepezil Hydrochloride Oral administration of donepezil to rats and rabbits during the period of organogenesis resulted in no adverse developmental effects. The highest doses (16 and 10 mg/kg/day, respectively) were approximately 15 and 7 times, respectively, the dose of donepezil at the RHD of memantine and donepezil hydrochlorides extended-release capsules on a mg/m 2 basis. Oral administration of donepezil (1, 3, or 10 mg/kg/day) to rats during late gestation and throughout lactation to weaning resulted in an increase in stillbirths and offspring mortality at the highest dose tested. The higher no-effect dose (3 mg/kg/day) is approximately 3 times the dose of donepezil at the RHD of memantine and donepezil hydrochlorides extended-release capsules on a mg/m 2 basis. 8.2 Lactation Risk Summary There are no data on the presence of memantine or donepezil in human milk, the effects on the breastfed infant, or the effects of memantine and donepezil hydrochlorides extended-release capsules or its metabolites on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for memantine and donepezil hydrochlorides extended-release capsules and any potential adverse effects on the breastfed infant from memantine and donepezil …

12.1 Mechanism of Action Memantine and donepezil hydrochlorides extended-release capsules contain two approved medications: memantine hydrochloride and donepezil hydrochloride. Each of those medications is postulated to have a different mechanism in Alzheimer's disease. Memantine Persistent activation of central nervous system NMDA receptors by the excitatory amino acid glutamate has been hypothesized to contribute to the symptomatology of Alzheimer's disease. Memantine is postulated to exert its therapeutic effect through its action as a low to moderate affinity uncompetitive (open channel) NMDA receptor antagonist which binds preferentially to the NMDA receptor-operated cation channels. There is no evidence that memantine prevents or slows neurodegeneration in patients with Alzheimer's disease. Donepezil 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 is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine in the central nervous system through reversible inhibition of its hydrolysis by acetylcholinesterase. There is no evidence that donepezil prevents or slows neurodegeneration in patients with Alzheimer's disease.

11 DESCRIPTION Memantine and donepezil hydrochlorides extended-release capsules contains memantine, an orally active NMDA receptor antagonist, as the hydrochloride salt and donepezil, a reversible inhibitor of the enzyme acetylcholinesterase, as the hydrochloride salt. Memantine Hydrochloride The chemical name for memantine hydrochloride is 1-amino-3,5-dimethyladamantane hydrochloride with the following structural formula: The molecular formula is C 12 H 21 N•HCl and the molecular weight is 215.76. Memantine hydrochloride occurs as a fine white to off-white powder. Memantine Hydrochloride Structural Formula Donepezil Hydrochloride The chemical name for donepezil hydrochloride is 2,3-dihydro-5,6-dimethoxy-2-[[1-(phenylmethyl)-4-piperidinyl]methyl]-1H-inden-1-one hydrochloride. The molecular formula is C 24 H 29 NO 3 •HCl and the molecular weight is 415.96. Donepezil hydrochloride is a white crystalline powder. Memantine and donepezil hydrochlorides extended-release capsules contain 14 mg or 28 mg memantine hydrochloride, 10 mg donepezil hydrochloride, and the following inactive ingredients: colloidal silicon dioxide, corn starch, ethylcellulose, hypromellose, lactose monohydrate, magnesium stearate, medium chain triglycerides, microcrystalline cellulose, triethyl citrate, ammonium hydroxide, oleic acid, polyethylene glycol, povidone, sugar spheres, and talc. The capsule shells contain gelatin and titanium dioxide and are imprinted with shellac and black iron oxide. Colorants are brilliant blue (14 mg/10 mg, 28 mg/10 mg), erythrosine (28 mg/10 mg) and ferric oxide yellow (14 mg/10 mg). Donepezil Hydrochloride Structural Formula

10 OVERDOSAGE Memantine hydrochloride and donepezil hydrochloride are the two active ingredients of memantine and donepezil hydrochlorides extended-release capsules. No specific antidote for memantine hydrochloride overdose is known; however, elimination of memantine can be increased by acidification of the urine. Tertiary anticholinergics such as atropine may be used as an antidote for donepezil hydrochloride overdose. In managing cases of overdose, consider the possibility of multiple drug involvement. In case of overdose, call Poison Control Center at 1-800-222-1222 for the latest recommendation. In general, supportive measures should be utilized, and treatment should be symptomatic. Memantine Hydrochloride Signs and symptoms most often accompanying overdosage with other formulations of memantine in clinical trials and from worldwide marketing experience, alone or in combination with other drugs and/or alcohol, include agitation, asthenia, bradycardia, confusion, coma, dizziness, ECG changes, increased blood pressure, lethargy, loss of consciousness, psychosis, restlessness, slowed movement, somnolence, stupor, unsteady gait, visual hallucinations, vertigo, vomiting, and weakness. The largest known ingestion of memantine worldwide was 2 grams in an individual who took memantine in conjunction with unspecified antidiabetic medications. This person experienced coma, diplopia, and agitation, but subsequently recovered. One patient participating in a memantine hydrochloride extended-release clinical trial unintentionally took 112 mg of memantine hydrochloride extended-release daily for 31 days and experienced elevated serum uric acid, elevated serum alkaline phosphatase, and low platelet count. No fatalities have been noted with overdoses of memantine alone. A fatal outcome has very rarely been reported when memantine has been ingested as part of overdosing with multiple drugs; in those instances, the relationship between memantine and a fatal outcome has been unclear. Donepezil Hydrochloride 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 donepezil hydrochloride 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 coadministered with quaternary anticholinergics such as glycopyrrolate. It is not known whether donepezil hydrochloride 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.

16 HOW SUPPLIED/STORAGE AND HANDLING 16.1 How Supplied 14 mg memantine hydrochloride and 10 mg donepezil hydrochloride: dark green opaque capsules, printed with "LPMD" on the cap and "14/10" on the body in black ink. Bottle of 30: NDC# 69680-183-30 28 mg memantine hydrochloride and 10 mg donepezil hydrochloride: blue opaque capsules, printed with "LPMD" on the cap and "28/10" on the body in black ink. Bottle of 30: NDC# 69680-185-30 16.2 Storage and Handling Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C and 30°C (59°F and 86°F) [see USP Controlled Room Temperature] . Dispense in a tight, light-resistant container, as defined in the USP.