Memantine (Axura or Ebixa )
The chemistry behind Memantine
The brain is noisy and has plaque.
When scientists talk about the noise of the brain, what they are referring to is the constant level of neurochemical activity that takes place in the brain. Signals have to rise above this chemical noise in order to be noticed and acted upon.
Plaque on the brain is analogous to plaque on teeth. All that neurochemical activity creates garbage, and some of this garbage is still chemically active. Scientists believe that substances like B-amyloid interfere with neurotransmitters and form a plaque that inhibits proper signal transfer1.
One of the neurotransmitter systems that plays an important role in memory formation and signal processing is the glutamatergic system. The two main components of this system are the neurotransmitter glutamate and the NMDA receptor. In a healthy brain, glutamate transmits a signal to receptor and then is recycled for future use.
In a brain afflicted with Alzheimer’s disease, plaques like B-amyloid interfere with glutamate recycling, so that levels of this neurotransmitter act as white noise in the brain, masking important information. Without proper signal transfer, memory is impaired.
One avenue of Alzheimer’s disease treatment is through the glutamatergic system. If the levels of excess glutamate can be effectively reduced, proper information transfer should be restored, and this should alleviate the symptoms of Alzheimer’s disease.
About Memantine
Memantine is a new product of Merz Pharmaceuticals which has been approved for use in Europe and the United States in the treatment of Alzheimer’s disease. Memantine’s biochemical action works on the glutamatergic system, rather than the dopaminergic system of many other Alzheimer’s medications.
Memantine is available in 10 mg tablets which may be taken with or without food. An oral solution is also available under the brand name Axura or Ebixa.
Memantine’s maximum recommended dosage for adults is 20 mg per day. The manufacturer recommends a beginning dosage of 5 mg per day for a period of one week. Each week the dosage should be increased by 5 mg per day until the maximum is reached.
Why Take Memantine?
Memantine controls the symptoms of Alzheimer’s disease by blocking the effects of excess glutamate in the glutamatergic system caused by B-amyloid plaque. This action allows for improved signal transfer, which translates into a reduction in the severity of Alzheimer’s disease symptoms.
Final thoughts on Memantine and Alzheimer’s disease
Common side-effects in persons taking Memantine include headache, sleepiness, constipation and dizziness. Less common side-effects of Memantine include fatigue, confusion, dizziness and abnormal gait. Persons with severe Alzheimer’s disease symptoms have also manifested hallucinations while on Memantine. Very rarely, seizures have occurred in persons taking Memantine.
Persons with a history of epilepsy, convulsions, or renal impairment should not take Memantine.
Persons taking other NMDA antagonists are advised not to take Memantine, as these drugs may interact with Memantine.
As with any drug, persons taking other medications should consult with their physician before using Memantine.
Women who are pregnant or nursing should consult with a doctor before using Memantine.