The Food and Drug Administration (FDA) has approved five medications for the treatment of Alzheimer disease. Four of these belong to the family of medications known as acetylcholinesterase inhibitors: donepezil (Aricept), rivastigmine (Exelon), galantamine (Razadyne), and tacrine (Cognex). The fifth medication, memantine (Namenda) acts as a partial antagonist of the neurotransmitter glutamate. Memantine can be prescribed together with one of the four cholinesterase inhibitors. In general, these medications exert modest beneficial effects. They may hold back symptom progression for 6 to 12 months. However, there is no convincing evidence that they slow down the progression of the underlying disease.
There is some limited evidence that the anti-oxidant vitamin E may slow progression of AD. There is rationale for taking a combination of vitamin E and vitamin C as dual anti-oxidants.
Disturbances of mood and behavior may benefit from psychotropic medications, including anti-depressants such as SSRIs (selective serotonin reuptake inhibitors). Medications originally developed as anti-convulsants may decrease agitation (e.g., valproic acid and gabapentin). Paranoid delusions or visual hallucinations may warrant treatment with atypical neuroleptic medications, such as respirdone, olanzepine, or quetiapine. Because of individual differences in symptoms and physiology, it is often difficult to predict which medication will work best. A dedicated and knowledgeable physician, together with patience during a trial and error process, is often required.