Remem 10

Memantine hydrochloride.

Each film-coated tablet contains memantine hydrochloride 10 mg.

Pharmacology: Pharmacodynamics: Mechanism of Action: Memantine hydrochloride is a low to moderate affinity, noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist which binds to NMDA receptor-operated cation channels. Memantine also blocks the 5-hydroxytryptamine-3 receptor (at a potency similar to the NMDA receptor) and nicotinic acetylcholine receptors (at one-sixth to one-tenth the potency). However, memantine has low to negligible affinity for gamma-aminobutyric acid, benzodiazepine, dopamine, adrenergic, histamine, and glycine receptors and for voltage-dependent calcium, sodium, or potassium channels.
Pharmacokinetics: Memantine is well-absorbed after oral administration and has linear pharmacokinetics over the therapeutic dose range. Following oral administration, memantine is highly absorbed with peak concentrations reached in about 3 to 7 hours. The mean volume of distribution of memantine is 9 to 11 L/kg, and the plasma protein binding is low (45%). Memantine undergoes partial hepatic metabolism; about 48% of administered drug is excreted unchanged in urine. The remainder is converted primarily to 3 polar metabolites, which posses minimal NMDA receptor antagonists activity; N-glucuronide conjugate, 6-hydroxy memantine, and 1-nitroso-deaminated memantine. A total of 74% of the administered dose is excreted as the sum of the parent drug and the N-glucuronide conjugate. The hepatic microsomal cytochrome P450 (CYP-450) enzyme system does not play a significant role in the metabolism of memantine. Renal clearance involves active tubular secretion moderated by pH-dependent tubular reabsorption. Memantine has a terminal elimination half-life of about 60 to 80 hours.

Memantine hydrochloride is used for the treatment of moderate to severe dementia of the Alzheimer's type.

Adult: Usual dosage: 20 mg/day.
Initial dosage: 5 mg once daily.
Dosage titration: Increase in 5 mg increments to 10 mg/day (5 mg twice a day), 15 mg/day (5 and 10 mg as separate doses), and 20 mg/day (10 mg twice a day). The minimum recommended interval between dose increases is 1 week.
Renal function impairment: Severe renal impairment (creatinine clearance [CrCl] 5 to 29 mL/min): Usual dose: A target dosage of 5 mg twice daily is recommended.
Mode of Administration: Memantine hydrochloride is administered orally without regard to meals.

Symptoms: Signs and symptoms associated with memantine overdosage in clinical trials and from worldwide market experience alone or in combination with other drugs and/or alcohol include agitation, asthenia, bradycardia, coma, confusion, dizziness, electrocardiogram (ECG) changes, increased blood pressure, lethargy, loss of consciousness, psychosis, restlessness, slowed movement, somnolence, stupor, unsteady gait, visual hallucinations, vertigo, vomiting and weakness.
Treatment: Utilize general supportive measures and symptomatic treatment. Elimination of memantine can be enhanced by acidification of urine.

Memantine HCl is contraindicated in patients with known hypersensitivity to the drug or any excipients used in the formulation.

Memantine has not been systematically evaluated in patients with a seizure disorder.
Conditions that raise urine pH may decrease the urinary elimination of memantine, resulting in increased plasma levels of memantine.

Use in Pregnancy: Pregnancy Category B. There are no adequate and well-controlled studies of memantine in pregnant women. Use memantine during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Use in Lactation: Not known whether memantine is distributed into human milk. However, since many drugs are distributed into human milk, caution is advised if memantine is administered in nursing women.

Adverse effects occurring in 2% or more of patients receiving memantine in clinical studies and more frequently than with placebo include dizziness (7%), confusion (6%), headache (6%), constipation (5%), cough (4%), hypertension (4%), back pain (3%), hallucination (3%), pain (3%), somnolence (3%), vomiting (3%), dyspnea (2%), and fatigue (2%).
Other adverse reactions: Cardiovascular: Cardiac failure, cerebrovascular accident, syncope transient ischemic attack (at least 1%); angina pectoris, atrial fibrillation, bradycardia, cardiac arrest, hypotension, myocardial infarction, postural hypotension, pulmonary embolism, thrombophlebitis (0.1% to 1%).
Central Nervous System: Aggressive reaction, ataxia, hypokinesia, vertigo (at least 1%); abnormal coordination, abnormal crying, abnormal thinking, amnesia, apathy, aphasia, cerebral hemorrhage, convulsions, delirium, delusion, depersonalization, emotional lability, extrapyramidal disorder, hemiplegia, hyperkinesias, hypertonia, hypesthesia, increased libido, involuntary muscle contractions, nervousness, neuralgia, neuropathy, neurosis, paranoid reaction, paresthesia, paroniria, personality disorder, psychosis, ptosis, sleep disorder, stupor, suicide attempt, tremor (0.1% to 1%).
Dermatologic: Rash (at least 1%); alopecia, cellulitis, dermatitis, eczema, erythematous rash, pruritus, skin ulceration, urticaria (0.1% to 1%).
Gastrointestinal: Diverticulitis, esophageal ulceration, gastroenteritis, GI hemorrhage, melena (0.1% to 1%).
Genitourinary: Frequent micturition (at least 1%); dysuria, hematuria, urinary retention (0.1% to 1%).
Hematologic/Lymphatic: Anemia (at least 1%); leucopenia (0.1% to 1%).
Metabolic/Nutritional: Decreased weight, increased alkaline phosphatase (at least 1%); aggravated diabetes mellitus, dehydration, hyponatremia, increased appetite (0.1% to 1%).
Respiratory: Pneumonia (at least 1%); apnea, asthma, hemoptysis, pulmonary edema (0.1% to 1%).
Special sense: Cataract, conjunctivitis (at least 1%); abnormal lacrimation, blepharitis, blurred vision, conjunctival hemorrhage, corneal opacity, decreased hearing, decreased visual acuity, diplopia, eye pain, glaucoma, macula lutea degeneration, myopia, retinal detachment, retinal hemorrhage, tinnitus, xerophthalmia (0.1% to 1%).
Miscellaneous: Allergic reaction, hypothermia (0.1% to 1%).

Concomitant use of memantine with alkalinizing agents that increase urine pH (e.g., carbonic anhydrase inhibitors, sodium bicarbonate) results in decreased memantine clearance with resulting increases in adverse effects.
Concomitant administration of memantine with a fixed combination of hydrochlorothiazide and triamterene did not affect bioavailability of either memantine or triamterene and maximum plasma concentrations and AUC of hydrochlorothiazide decreased by only 20%.
Concomitant administration of memantine with other NMDA antagonists (e.g., amantadine, ketamine, dextromethorphan) has not been systematically evaluated. Use with caution.
Concomitant use of memantine with the acetylcholinesterase inhibitor donepezil did not affect the pharmacokinetics of either drug or substantially alter acetylcholinesterase inhibition by donepezil.

Store at a temperature below 30°C.

Neurodegenerative Disease Drugs

N06DX01 - memantine ; Belongs to the class of other anti-dementia drugs.

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