Classifications: n-methyl-d-aspartate (nmda) receptor antagonist; antidementia agent; Therapeutic: antidementia agent; nmda receptor antagonist
Pregnancy Category: B
5 mg, 10 mg tablets; 2 mg/mL solution
Glutamate activation at the (N-methyl-D-aspartate) NMDA receptor is needed for memory and learning processes in the brain. Excess glutamate may play a role in
Alzheimer's disease by over-stimulating NMDA receptors, thus causing increased Ca2+ movement into neurons leading to neuronal damage. Memantine is a low-affinity, uncompetitive antagonist at NMDA receptors
in the brain. Blockade of NMDA receptors may slow intracellular calcium accumulation, preventing nerve damage without interfering
with actions of glutamate that are required for memory and learning.
Improves cognitive functioning in moderate-to-severe Alzheimer's disease (AD) and in mild-to-moderate vascular dementia.
Treatment of symptoms of moderate to severe Alzheimer's disease.
Treatment of moderate to severe vascular dementia.
Renal failure. Safety and efficacy in children are unknown.
Moderate to severe renal impairment; history of seizure disorder; older adults; concurrent use with carbonic anhydrase inhibitors,
or sodium bicarbonate, pregnancy (category B), lactation.
Route & Dosage
Adult: PO Initiate with 5 mg once daily, increase dose by 5 mg/wk over a 3-wk period to target dose of 10 mg b.i.d.
Severe Renal Impairment
Decrease to 5 mg b.i.d.
- Note: The recommended interval between dose increases is 1 wk.
- Dose reductions should be considered with moderate renal impairment.
- Store between 15°30° C (59°86° F).
Adverse Effects (≥1%)Body as a Whole: Fatigue
, pain, flu-like symptoms
, peripheral edema. CNS:
Dizziness, headache, confusion, somnolence, hallucinations, agitation, insomnia
, abnormal gait, depression
, anxiety, syncope,
TIA, vertigo, ataxia, hypokinesia, aggressive reaction. CV:
Hypertension, cardiac failure. GI: Constipation
, vomiting, diarrhea
, nausea, anorexia. Hematologic: Anemia
Weight loss, increased alkaline phosphatase
Back pain, arthralgia
, upper respiratory infections, pneumonia
Rash. Special Senses: Conjunctivitis
Urinary incontinence, UTI, frequent micturition.
Drugs that increase the pH of the urine (CARBONIC ANHYDRASE INIBITORS
, sodium bicarbonate
) may increase levels of memantine; may enhance the effects of amantadine, dextromethorphan, ketamine, bromocriptine, pergolide, pramipexole,
may enhance the adverse effects of levodopa
100% from GI tract. Duration:
46 h. Distribution:
Easily crosses the bloodbrain barrier. Metabolism:
Primarily excreted unchanged in urine. Increases in urinary pH can decrease elimination of drug. Half-Life:
Assessment & Drug Effects
- Monitor respiratory and CV status, especially with preexisting heart disease.
- Assess for and report S&S of focal neurologic deficits (e.g., TIA, ataxia, vertigo).
- Lab tests: Periodic Hct & Hgb, serum sodium, alkaline phosphatase, and blood glucose.
- Monitor diabetics for loss of glycemic control.
Patient & Family Education
- Report any of the following to the physician: problems with vision, skin rash, shortness of breath, swelling in throat or
tongue, agitation or restlessness, confusion, dizziness, or incontinence.
- Do not drive or engage in other hazardous activities until reaction to drug is known.