- What is memantine, and how does it work (mechanism of action)?
- What brand names are available for memantine?
- Is memantine available as a generic drug?
- Do I need a prescription for memantine?
- What are the uses for memantine?
- What are the side effects of memantine?
- What is the dosage for memantine?
- Which drugs or supplements interact with memantine?
- Is memantine safe to take if I'm pregnant or breastfeeding?
- What else should I know about memantine?
What is memantine, and how does it work (mechanism of action)?
- Memantine is an oral medication for treating patients with Alzheimer's disease. Other medications used for Alzheimer's disease affect acetylcholine, one of the neurotransmitter chemicals that nerve cells in the brain use to communicate with one another. These drugs - galantamine (Razadyne - formerly known as Reminyl), donezepil (Aricept), rivastigmine (Exelon), and tacrine (Cognex) - inhibit the enzyme acetylcholinesterase that destroys acetylcholine and thereby increase the effects of acetylcholine. Memantine's effects are independent of acetylcholine and acetylcholinesterase. Glutamate is the main excitatory neurotransmitter in the brain. It is believed that too much stimulation of nerve cells by glutamate may be responsible for the degeneration of nerves that occurs in some neurological diseases such as Alzheimer's disease. Like other neurotransmitters, glutamate is produced and released by nerve cells in the brain. The released glutamate then travels to nearby nerve cells where it attaches to a receptor on the surface of the cells called the N-methyl-D-aspartate (NMDA) receptor. Memantine blocks this receptor and thereby decreases the effects of glutamate. It is thought that by blocking the NMDA receptor and the effects of glutamate, memantine may protect nerve cells from excess stimulation by glutamate.
- Memantine was approved by the FDA in October 2003.
What are the uses for memantine?
Memantine is used for the treatment of moderate to severe dementia associated with Alzheimer's. Dementia can be categorized into three levels of severity: mild in which patients are alert and sociable, but forgetfulness begins to interfere with daily living, moderate which often is the longest stage of the disease with deterioration of intellect, logic, behavior, and function, and severe, in which there is loss of long-term memory and language skills. Patients with severe Alzheimer's may require 24-hour care and can no longer complete basic self-care tasks including washing, eating, and using the bathroom.
What are the side effects of memantine?
The most common side effects of memantine are:
- Increases in blood pressure
- Back pain
- Sleepiness (somnolence)
- Difficulty breathing
Memantine may cause a serious skin reaction called Stevens-Johnson syndrome.
Other potential serious side effects include:
What is the dosage for memantine?
- The usual starting dose of memantine tablets is 5 mg once daily.
- The dose usually is increased to 5 mg twice daily, then 5 mg and 10 mg as separate doses daily, and finally 10 mg twice daily.
- Memantine can be taken with or without food.
- The initial recommended dose of memantine capsules is 7 mg daily.
- The dose may be increased weekly by 7 mg daily and the maximum dose is 28 mg daily.
- Capsules may be swallowed whole or opened and sprinkled on spoonsful of applesauce.
- Capsules should not be crushed or chewed.
Which drugs or supplements interact with memantine?
- Medicines that make the urine more alkaline (for example, carbonic anhydrase inhibitors such as acetazolamide (Diamox) and sodium bicarbonate would be expected to reduce the elimination of memantine by the kidneys and might increase the blood levels and the risk of side effects of memantine.
- Combining memantine with other NMDA receptor antagonists (for example, amantadine [Symmetrel], ketamine, and dextromethorphan) has not been evaluated and should be done cautiously.
Is memantine safe to take if I'm pregnant or breastfeeding?
- Memantine given in high doses to pregnant rats and rabbits did not affect the offspring. However, studies have not been conducted in pregnant women. Memantine should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.
- It is not known if memantine is excreted into breast milk.
Multimedia: Slideshows, Images & Quizzes
Alzheimers Disease Quiz: Stages, Symptoms & Signs
Take the Alzheimer's Quiz to discover some of the mysteries behind this cognitive disorder. Learn causes, symptoms, treatments,...
Picture of Alzheimer's Disease
In the early stages of Alzheimer's disease, patients may experience memory impairment, lapses of judgment, and subtle changes in...
Dementia, Alzheimer's Disease, and Aging Brains
What is dementia? Learn about dementia disorders such as Lewy Body Dementia, Alzheimer's disease (AD), Vascular (multi-infarct)...
Caring for Someone With Alzheimer's Disease
Use this guide for advice on caring for someone with Alzheimer's. Learn to spot early signs and symptoms of Alzheimer's disease...
Alzheimer's Disease Symptoms & Early Diagnosis
Learn the early warning signs and symptoms of Alzheimer's disease. Memory loss and confusion can be signs of normal aging, but...
Alzheimer's Diagnosis: Your Family's Questions Answered
Is there any difference between Alzheimer's disease and Dementia? Is Alzheimer's disease deadly? Find out the truth about...
Related Disease Conditions
Fibromyalgia is a chronic pain condition characterized by symptoms such as fatigue, sleep disturbances, and tender points. Stress...
Dementia is defined as a significant loss of intellectual abilities such as memory capacity, severe enough to interfere with...
Mental health is an optimal way of thinking, relating to others, and feeling. All of the diagnosable mental disorders fall under...
Alzheimer's Disease: Financial Planning
Alzheimer's disease can be not only mentally devastating to an indivdiual and family, it can also be emotionally devastating....
Alzheimer's Disease Patient Caregiver Guide
Caring for a loved one or patient with Alzheimer's can become a difficult and overwhelming task at times. This guide helps...
Alzheimer's disease is a common cause of dementia. Symptoms and warning signs of Alzheimer's disease include memory loss,...
7 Alzheimer's Disease Stages and Symptoms
The signs and symptoms of Alzheimer's disease depend on the stage of the disease. Some doctors and researchers disagree in regard...
Treatment & Diagnosis
Medications & Supplements
Prevention & Wellness
- Treatments for Alzheimer's Proving Elusive
- FDA Approves Combo Pill for Alzheimer's Disease
- Advanced Dementia Patients Often Given Unhelpful Meds: Study
- Daily High-Dose Vitamin E Might Delay Alzheimer's
- Experimental Alzheimer's Drug Shows Promise, Study Finds
- For Alzheimer's Caregivers, Patience and Compassion Are Key
- Alzheimer's Treatment Shows Promise in Small, 3-Year Trial
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.