From the Guidelines
Namenda (memantine) can cause several side effects, with the most common being dizziness, headache, confusion, and constipation, as reported in studies such as 1 and 1. Some patients may experience drowsiness, fatigue, high blood pressure, back pain, and anxiety. More serious but less common side effects include hallucinations, seizures, shortness of breath, and severe allergic reactions (rash, itching, swelling).
Common Side Effects
- Dizziness
- Headache
- Confusion
- Constipation
- Drowsiness
- Fatigue
- High blood pressure
- Back pain
- Anxiety Namenda works by regulating glutamate activity in the brain, which can cause these neurological side effects as it modifies brain signaling.
Serious Side Effects
- Hallucinations
- Seizures
- Shortness of breath
- Severe allergic reactions (rash, itching, swelling) The medication is typically started at a low dose (5 mg once daily) and gradually increased to reduce side effect severity.
Management of Side Effects
- Regular follow-up appointments are important to monitor for side effects and adjust dosing if needed.
- If you experience severe or persistent side effects, contact your healthcare provider immediately rather than stopping the medication abruptly. As reported in 1, the proportion of patients withdrawing because of adverse events ranged from 0% to 12% in the placebo groups and 0% to 55% in the treatment groups, highlighting the importance of careful monitoring and management of side effects.
From the FDA Drug Label
Memantine hydrochloride oral solution may cause side effects , including: The most common side effects of memantine hydrochloride oral solution include: dizziness headache confusion constipation These are not all the possible side effects of memantine hydrochloride oral solution For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
The possible side effects of Namenda (memantine) include:
- Dizziness
- Headache
- Confusion
- Constipation 2
From the Research
Namenda Side Effects
- The most common side effects of Namenda (memantine) include somnolence, as reported in studies 3, 4.
- Other potential side effects of memantine monotherapy and combination therapy with cholinesterase inhibitors include gastrointestinal symptoms, such as those associated with donepezil, galantamine, and rivastigmine monotherapies 3.
- Combination therapy with memantine and cholinesterase inhibitors has been shown to be well-tolerated, with a discontinuation rate similar to that of the placebo 3, 5.
- Individual side effects were not significantly different between combination therapy and monotherapy groups 5, 6.
Safety and Efficacy
- Memantine has been shown to improve cognitive functions and behavioral disturbances in patients with Alzheimer's disease, both as monotherapy and in combination with cholinesterase inhibitors 3, 4.
- The safety of memantine, as measured by all-cause discontinuation, is comparable or superior to that of the placebo 3, 4.
- Combination therapy with memantine and cholinesterase inhibitors has been found to be beneficial for the treatment of moderate-to-severe Alzheimer's disease, with significant effects on behavioral disturbance scores, activity of daily living scores, and global assessment scores 5, 6.