MEMANTINE HYDROCHLORIDE

Memantine hydrochloride extended-release capsules is an orally active NMDA receptor antagonist. 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 and is soluble in water. Memantine hydrochloride extended-release capsules are supplied for oral administration as 7 mg, 14 mg, 21 mg and 28 mg capsules. Among them, 7 mg strength is supplied in opaque light green cap and opaque white body capsule, with "LPM" black imprint on the cap and "7 mg" black imprint on the body, 14 mg strength is supplied in opaque blue cap and opaque white body capsule, with "LPM" black imprint on the cap and "14 mg" black imprint on the body, 21 mg strength is supplied in opaque white cap and opaque white body capsule, with "LPM" black imprint on the cap and "21 mg" black imprint on the body, 28 mg strength is supplied in the opaque rich yellow cap and opaque white body capsule, with "LPM" black imprint on the cap and "28 mg" black imprint on the body. Each capsule contains extended-release white to off-white beads with the labeled amount of memantine hydrochloride and the following inactive ingredients: sugar spheres (sucrose, maize starch, and dextrin), polyvinylpyrrolidone, hypromellose, talc, polyethylene glycol, triethyl citrate, ethylcellulose, ammonium hydroxide, oleic acid, and medium chain triglycerides in hard gelatin capsules. In addition, the capsule shells contain gelatin and titanium dioxide and are imprinted with black ink. Colorants in capsule shells are brilliant blue (7 mg, 14 mg), erythrosine (14 mg only) and ferric oxide yellow (7 mg, 28 mg). The black ink mainly contains shellac, black iron oxide, dehydrated alcohol, purified water and propylene glycol, with trace amount of isopropyl alcohol, butyl alcohol, strong ammonia solution and potassium hydroxide. Structure

Memantine hydrochloride extended-release capsules is indicated for the treatment of moderate to severe dementia of the Alzheimer's type. Memantine hydrochloride extended-release capsules is a N-methyl-D-aspartate (NMDA) receptor antagonist indicated for the treatment of moderate to severe dementia of the Alzheimer's type. ( 1 )

The recommended starting dose of memantine hydrochloride extended-release capsules is 7 mg once daily; the dose should be increased in 7 mg increments to the recommended maintenance dose of 28 mg once daily; the minimum recommended interval between dose increases is one week. ( 2.1 ) Patients with severe renal impairment: the recommended maintenance dose of memantine hydrochloride extended-release capsules is 14 mg once daily. ( 2.3 ) 2.1 Recommended Dosing The dosage of memantine hydrochloride extended-release capsules shown to be effective in a controlled clinical trial is 28 mg once daily. The recommended starting dose of memantine hydrochloride extended-release capsules is 7 mg once daily. The dose should be increased in 7 mg increments to the recommended maintenance dose of 28 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 recommended dose is 28 mg once daily. Memantine hydrochloride extended-release capsules can be taken with or without food. Memantine hydrochloride extended-release capsules can be taken intact or may be opened, sprinkled on applesauce, and thereby swallowed. The entire contents of each memantine hydrochloride extended-release capsule should be consumed; the dose should not be divided. Except when opened and sprinkled on applesauce, as described above, memantine hydrochloride extended-release capsules should be swallowed whole. Memantine hydrochloride extended-release capsules should not be divided, chewed, or crushed. If a patient misses a single dose of memantine hydrochloride extended-release capsules, that patient should not double up on the next dose. The next dose should be taken as scheduled. If a patient fails to take memantine hydrochloride extended-release capsules for several days, dosing may need to be resumed at lower doses and retitrated as described above. 2.2 Switching from NAMENDA to Memantine Hydrochloride Extended-Release Capsules Patients treated with NAMENDA may be switched to memantine hydrochloride extended-release capsules as follows: It is recommended that a patient who is on a regimen of 10 mg twice daily of NAMENDA be switched to memantine hydrochloride extended-release capsules 28 mg once daily capsules the day following the last dose of 10 mg NAMENDA. There is no study addressing the comparative efficacy of these 2 regimens. In a patient with severe renal impairment, it is recommended that a patient who is on a regimen of 5 mg twice daily of NAMENDA be switched to memantine hydrochloride extended-release capsules 14 mg once daily capsules the day following the last dose of 5 mg NAMENDA. 2.3 Dosing in Patients with Renal Impairment In patients with severe renal impairment (creatinine clearance of 5 – 29 mL/min, based on the Cockcroft-Gault equation), the recommended maintenance dose (and maximum recommended dose) is 14 mg/day [see Clinical Pharmacology ( 12.3 )] .

Memantine hydrochloride extended-release capsules is contraindicated in patients with known hypersensitivity to memantine hydrochloride or to any excipients used in the formulation . Memantine hydrochloride extended-release capsules is contraindicated in patients with known hypersensitivity to memantine hydrochloride or to any excipients used in the formulation. ( 4 )

The most commonly observed adverse reactions occurring at a frequency of at least 5% and greater than placebo with administration of memantine hydrochloride extended-release capsules 28 mg/day were headache, diarrhea and dizziness. ( 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 Trial s Experience Memantine hydrochloride extended-release capsules was evaluated in a double-blind placebo-controlled trial in which a total of 676 patients with moderate to severe dementia of the Alzheimer's type (341 patients on memantine hydrochloride extended-release capsules 28 mg/day and 335 patients on placebo) were treated for up to 24 weeks. 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. Adverse Reactions Leading to Discontinuation In the placebo-controlled clinical trial of memantine hydrochloride extended-release capsules, the proportion of patients in the memantine hydrochloride extended-release capsules group and the placebo group who discontinued treatment due to adverse reactions was 10% and 6%, respectively. The most common adverse reaction that led to treatment discontinuation in the memantine hydrochloride extended-release capsules group was dizziness, at a rate of 1.5%. Most Common Adverse Reactions The most commonly observed adverse reactions seen in patients administered memantine hydrochloride extended-release capsules in the controlled clinical trial, defined as those occurring at a frequency of at least 5% in the memantine hydrochloride extended-release capsules group and at a frequency higher than placebo, were headache, diarrhea and dizziness. Table 1 lists adverse reactions that were observed at an incidence of ≥ 2% in the memantine hydrochloride extended-release capsules group and occurred at a rate greater than placebo. Table 1: Adverse Reactions Observed with a Frequency of ≥ 2% in the Memantine Hydrochloride Extended-Release Capsules Group and at a Rate Greater than Placebo Adverse R eaction Placebo (n = 335) % M emantine Hydrochloride Extended-R elease Capsules 28 mg (n = 341) % Gastrointestinal Disorders Diarrhea 4 5 Constipation 1 3 Abdominal pain 1 2 Vomiting 1 2 Infections and I nfestations Influenza 3 4 Investigations Weight, increased 1 3 Musculoskeletal and C onnective T issue D isorders Back pain 1 3 Nervous S ystem D isorders Headache 5 6 Dizziness 1 5 Somnolence 1 3 Psychiatric D isorders Anxiety 3 4 Depression 1 3 Aggression 1 2 Renal and U rinary D isorders Urinary incontinence 1 2 Vascular D isorders Hypertension 2 4 Hypotension 1 2 Seizure Memantine has not been systematically evaluated in patients with a seizure disorder. In clinical trials of memantine, seizures occurred in 0.3% of patients treated with memantine and 0.6% of patients treated with placebo. 6. 2 Post m arketing Experience The following adverse reactions have been identified during post-approval use of memantine. 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. These reactions include: Blood and Lymphatic System Disorders: agranulocytosis, leukopenia (including neutropenia), pancytopenia, thrombocytopenia, thrombotic thrombocytopenic purpura. Cardiac Disorders: cardiac failure congestive. Gastrointestinal Disorders: pancreatitis. Hepatobiliary Disorders: hepatitis. Psychiatric Disorders: suicidal ideation. Renal and Urinary Disorders: acute renal failure (including increased creatinine and renal insufficiency). Skin Disorders: Stevens Johnson syndrome.

7.1 Drugs That Make 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 effects. 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 with O th er N-methyl-D-aspartate (NMDA) A ntagonists The combined use of memantine hydrochloride extended-release capsules with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated and such use should be approached with caution.