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Pharmacologic class: N-methyl-D-aspartate receptor antagonist (NMDA)
Therapeutic class: Anti-Alzheimer's agent
Pregnancy risk category B
Unclear. Thought to act as a low- to moderate-affinity NMDA receptor antagonist, binding to NMDA receptor-operated channels. (Activation of these channels is thought to contribute to Alzheimer's symptoms.)
Oral solution: 2 mg/ml
Tablets: 5 mg, 10 mg
Tablets (titration pack): 28 tablets of 5 mg and 21 tablets of 10 mg
Indications and dosages
➣ Moderate to severe Alzheimer's-type dementia
Adults: Initially, 5 mg P.O. daily. Then titrate at intervals of at least 1 week in 5-mg increments, to a maximum of 10 mg P.O. b.i.d.
• Moderate renal impairment
• Hypersensitivity to drug or its components
Use cautiously in:
• neurologic conditions, moderate to severe renal impairment, genitourinary conditions that increase pH
• pregnant or breastfeeding patients.
• Give with or without food.
CNS: dizziness, headache, syncope, aggressive reaction, confusion, somnolence, hallucinations, agitation, insomnia, vertigo, ataxia, abnormal gait, hypokinesia, anxiety, transient ischemic attack, cerebrovascular accident (CVA)
CV: hypertension, cardiac failure
EENT: cataract, conjunctivitis
GI: nausea, vomiting, diarrhea, constipation, anorexia
GU: frequent voiding, urinary incontinence, urinary tract infection
Musculoskeletal: back pain, arthralgia
Respiratory: cough, dyspnea, bronchitis, pneumonia
Other: weight loss, fatigue, pain, falls, flulike symptoms, peripheral edema
Drug-drug. Cimetidine, hydrochlorothiazide, nicotine, quinidine, ranitidine, triamterene: altered blood levels of both drugs
Urine-alkalizing drugs (carbonic anhydrase inhibitors, sodium bicarbonate): decreased memantine elimination
Drug-diagnostic tests. Alkaline phosphatase: increased level
☞ Check for heart failure and signs and symptoms of CVA.
• Monitor kidney function tests.
• Tell patient to take with or without food.
• Instruct patient or caregiver not to mix solution with other liquids and to take or give oral solution only with included dosing device.
• Make sure patient or caregiver understands dose escalation.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.
memantineAn NMDA (N-methyl D-aspartate) receptor antagonist that counters the toxic effects of glutamate excess to manage the symptoms of moderate to severe Alzheimer’s disease.
Hallucinations, confusion, dizziness, headache, hypertonia, nausea, vomiting, constipation, hypertonia, cystitis, increased libido.
Interferes with homocysteine binding at the NMDA receptor; homocysteine also mediates excitotoxicity, and disturbs glutamatergic neurotransmission.