Dementa® 5 Tablet:Each film coated tablet contains Memantine Hydrochloride INN 5 mg.
Dementa® (Memantine HCl) is a voltage dependent, uncompetitive, with moderate affinity, NMDA (N-methyl-D-aspartate) receptor antagonist that binds to the NMDA receptor channel and regulates the Calcium
influx into the neurons. The chemical name of Memantine Hydrochloride is 1-amino-3, 5 -dimethyladamantane Hydrochloride.
Mode of Action
Persistent activation of N-methyl-D-aspartate (NMDA) receptors in Central Nervous System 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 as an uncompetitive (open-channel) NMDA receptor antagonist which binds preferentially to the NMDA receptor-operated cation channels.
Pharmacokinetics: Memantine(Dementa®) is well absorbed after oral administration and has linear pharmacokinetics over the therapeutic dose range. It is excreted predominantly unchanged in the urine and has a terminal elimination half life of about 60-80 hours.
Following oral administration, Memantine (Dementa®) is highly absorbed with peak concentrations reached in about 3-7 hours. Food has no effect on the absorption of Memantine. The mean volume of distribution of Memantine is 9-11 L/kg and the plasma protein binding is low (45%).
Memantine (Dementa®) undergoes partial hepatic metabolism. About 48% of administered drug is excreted unchanged in urine; the remainder is converted primarily to three polar metabolites which possess minimal
NMDA receptor antagonistic activity: the 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 CYP-450 enzyme system does not play a significant role in the metabolism of Memantine.
Dementa is indicated for the treatment of all froms of dementia of the Alzheimer's type. Memantine may also be indicated in other types of dementia.
The recommended maintenance dose of Dementa for adults and older patients is 20 mg every day. In order to lower the risk of side effects, the dose should be achieved by upward titration with 5 mg per week over 3 weeks,
achieving the maintenance dose of 20 mg/day from the start of week 4 according to the following dosage
guideline:
A.M. (Morning) | P.M. (Night) | |
Week 1 (Everyday) | 5 mg (1 tablet) | No dose |
Week 2 (Everyday) | 5 mg (1 tablet | 5 mg (1 tablet |
Week 3 (Everyday) | 5 mg (1 tablet) | |
Most frequent side effects (frequency of 2% or less) include hallucination, confusion, dizziness, headache and fatigue. Occasional side effects include anxiety, hypertonus (heightened muscle tension), vomiting, bladder infections and increased sexual drive.If there is a history of epileptic seizures, there is a slight chance that Dementa may increase the probability of an attack.
Caregivers should be instructed in the recommended administration (twice per day for doses above 5 mg) and dose escalation (minimum interval of one week between dose increases). If the patients suffer from kidney dysfunction, the kidney function should be monitored at regular basis.
Neurological Conditions Seizures: Memantine has not been systematically evaluated in patients with a seizure disorder. One clinical trial shows that seizures occurred in 0.2% of patients treated with Memantine and 0.5% of patients treated with placebo.
Carcinogenesis, Mutagenesis and Impairment of Fertility Study shows that no risk of carcinogenesis, mutagenesis and impairment of fertility are caused after Memantine use.
Operating Vehicles or Machinery Taking Memantine may alter the reaction time significantly; therefore safe driving and safe operation of machinery may no longer be possible.
Missed Dose If any dose is missed, just wait and take the next dose at the usual time. Do not double the dose to compensate for the missed dose.
Memantine (Dementa®) is contraindicated in patients with known hypersensitivity to Memantine Hydrochloride or to any excipients used in the formulation.
Pregnancy Category B. Yet there are no adequate and well-controlled studies of Memantine in pregnant women. Memantine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
It is not known whether Memantine is excreted in human breast milk. Because many drugs are excreted in human milk, caution should be exercised when Memantine is administered to a nursing mother.
Dementa® 5 Tablet: Each carton contains 3x10's Tablets in blister pack.
Amantadine, Anticholinergics, Anticonvulsives, Baclofen, Barbiturates, Cimetidine, Dantrolene, Dextromethorphan, Dopaminergic, Hydrochlorothiazide, Ketamine, Neuroleptics, Nicotine, Procainamide,
Quinidine, Quinine, Ranitidine.
Store in a cool and dry place, protected from light. Keep this medication out of reach of children.