Memantine Side Effects
Some side effects of memantine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to memantine: oral capsule extended release, oral solution, oral tablet
Along with its needed effects, memantine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking memantine:Less common
- Bloating or swelling of the face, arms, hands, lower legs, or feet
- blurred vision
- pounding in the ears
- rapid weight gain
- slow or fast heartbeat
- tingling of the hands or feet
- unusual weight gain or loss
- Abdominal or stomach pain
- black, tarry stools
- bleeding gums
- blistering, peeling, or loosening of the skin
- blood in the urine or stools
- chest pain
- continuing vomiting
- dark-colored urine
- decreased urine output
- fast, pounding, or irregular heartbeat or pulse
- general feeling of tiredness or weakness
- high fever
- high or low blood pressure
- increased sweating
- infection from breathing foreign substances into the lungs
- light-colored stools
- lip smacking or puckering
- loss of consciousness
- muscle twitching
- no blood pressure
- no breathing
- no pulse
- numbness or tingling in the face, arms, or legs
- pain in the stomach, side, or abdomen, possibly radiating to the back
- pain or swelling in the arms or legs without any injury
- pain, tension, and weakness upon walking that subsides during periods of rest
- pinpoint red spots on the skin
- pounding, slow heartbeat
- puffing of the cheeks
- rapid or worm-like movements of the tongue
- rapid weight gain
- recurrent fainting
- red irritated eyes
- red skin lesions, often with a purple center
- severe constipation
- severe headache
- severe muscle stiffness
- severe vomiting
- sores, ulcers, or white spots in the mouth or on the lips
- sudden severe weakness
- swelling of the face, ankles, or hands
- total body jerking
- trouble with speaking or walking
- troubled breathing
- twitching, twisting, or uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
- uncontrolled chewing movements
- unusual bleeding or bruising
- unusually pale skin
- yellow eyes and skin
Some side effects of memantine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:More common
- back pain
- bladder pain
- bloody or cloudy urine
- change in walking and balance
- clumsiness or unsteadiness
- cough producing mucus
- difficult, burning, or painful urination
- difficulty with breathing
- difficulty with moving
- dry mouth
- feeling sad or empty
- frequent urge to urinate
- general feeling of discomfort or illness
- joint pain
- loss of appetite
- loss of bladder control
- loss of interest or pleasure
- lower back or side pain
- muscle pain or stiffness
- pain in the joints
- seeing, hearing, or feeling things that are not there
- shortness of breath
- sleepiness or unusual drowsiness
- sore throat
- tightness in the chest
- trouble with concentrating
- trouble with sleeping
- unusual tiredness or weakness
- Burning feeling in the chest or stomach
- burning, numbness, pain, or tingling in all fingers except smallest finger
- cold sweats
- cool pale skin
- decreased interest in sexual intercourse
- difficulty with swallowing
- general feeling of discomfort or illness
- inability to have or keep an erection
- increased hunger
- large amounts of fat in the blood
- loss in sexual ability, desire, drive, or performance
- slurred speech
- stomach cramps
- stomach upset
- tenderness in the stomach area
- watery or bloody diarrhea
For Healthcare Professionals
Applies to memantine: oral capsule extended release, oral kit, oral solution, oral tablet
Cardiovascular side effects have included hypertension (4%). Cardiac failure, angina pectoris, bradycardia, myocardial infarction, thrombophlebitis, atrial fibrillation, hypotension, cardiac arrest, postural hypotension, pulmonary embolism, and pulmonary edema have been reported during clinical trials, but no direct correlation to memantine has been established. Atrioventricular block, prolonged QT interval, supraventricular tachycardia, and tachycardia have been reported subsequent to the worldwide marketing of memantine.
In a trial testing the use of memantine in MS patients with cognitive impairment, nine out of nineteen patients reported a worsening of their neurologic symptoms that deteriorated their quality of life. After stopping the medication, the patients reverted to their baseline disability within a few days.
Nervous system side effects have included dizziness (7%) and headache (6%). Transient ischemic attack, cerebrovascular accident, vertigo, ataxia, hypokinesia, paresthesia, convulsions, extrapyramidal disorder, hypertonia, tremor, aphasia, hypoesthesia, abnormal coordination, hemiplegia, hyperkinesia, involuntary muscle contractions, stupor, cerebral hemorrhage, neuralgia, ptosis, and neuropathy have been reported during clinical trials, but these adverse events may not be necessarily related to memantine. Carpal tunnel syndrome, cerebral infarction, grand mal convulsions, intracranial hemorrhage, and neuroleptic malignant syndrome have been reported subsequent to the worldwide marketing of memantine.
Gastrointestinal side effects have included constipation (5%) and vomiting (3%). Gastroenteritis, diverticulitis, gastrointestinal hemorrhage, melena, and esophageal ulceration have been reported during clinical trials, but no direct correlation to memantine has been established. Colitis, dysphagia, gastritis, ileus, acute pancreatitis, gastroesophageal reflux have been reported subsequent to the worldwide marketing of memantine.
Musculoskeletal side effects have included back pain (3%), bone fracture, tardive dyskinesia, and dyskinesia.
Psychiatric side effects have included confusion (6%), somnolence (3%), and hallucination (3%). Aggressive reaction, delusion, personality disorder, emotional lability, nervousness, sleep disorder, libido increased, psychosis, amnesia, apathy, paranoid reaction, thinking abnormal, crying abnormal, appetite increased, paroniria, delirium, depersonalization, neurosis, and suicide attempt have been reported during clinical trials although not direct correlation to memantine has been established,
Respiratory side effects have included coughing (4%) and dyspnea (2%). Pneumonia, apnea, asthma, and hemoptysis have been reported during clinical trials although these adverse events may not be necessarily related to memantine.
Hematologic side effects reported during clinical trials have included anemia and leukopenia, although no direct relationship to memantine has been established. Postmarketing adverse events reporting from outside the U.S. have included thrombocytopenia. Thrombocytopenia and hyperlipidemia have been reported subsequent to the worldwide marketing of memantine.
Dermatologic side effects reported during clinical trials have included rash, skin ulceration, pruritus, cellulitis, eczema, dermatitis, erythematous rash, alopecia and urticaria although these adverse events may not be necessarily related to memantine.
Stevens-Johnson syndrome has been reported subsequent to the worldwide marketing of memantine. Postmarketing adverse events reporting from outside the U.S. have included acne.
Metabolic side effects reported during clinical trials have included increased alkaline phosphatase, decreased weight, dehydration, hyponatremia, and aggravated diabetes mellitus although these adverse events may not be necessarily related to memantine.
Ocular side effects reported during clinical trials have included cataract, conjunctivitis, macula lutea degeneration, decreased visual acuity, decreased hearing, tinnitus, blepharitis, blurred vision, corneal opacity, glaucoma, conjunctival hemorrhage, eye pain, retinal hemorrhage, xerophthalmia, diplopia, abnormal lacrimation, myopia, and retinal detachment although these adverse events may not be necessarily related to memantine.
Genitourinary side effects reported during clinical trials have included frequent micturition, dysuria, hematuria, and urinary retention, although these adverse events may not be necessarily related to memantine treatment. Postmarketing adverse events reporting outside the U.S. have included impotence.
Other side effects including claudication, chest pain, malaise, restlessness, and sudden death have been reported subsequent to the worldwide marketing of memantine.
Hepatic side effects have included hepatic failure, which was reported subsequent to the worldwide marketing of memantine.
Renal side effects have included acute renal failure, which has been reported subsequent to the worldwide marketing of memantine.
More memantine resources
- memantine MedFacts Consumer Leaflet (Wolters Kluwer)
- memantine Advanced Consumer (Micromedex) - Includes Dosage Information
- Memantine Hydrochloride Monograph (AHFS DI)
- Namenda Prescribing Information (FDA)
- Namenda Consumer Overview
- Namenda XR Prescribing Information (FDA)
- Namenda XR extended-release capsules MedFacts Consumer Leaflet (Wolters Kluwer)
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