Migraine patients can sometimes benefit from an Alzheimer’s drug, Namenda (memantine). All drugs for the preventive treatment of migraines, including Botox, had been first approved for a completely different indication. Beta blockers and other high blood pressure drugs, epilepsy drugs, and antidepressants are the most commonly used medications for migraine. It is surprising that such a wide variety of medications with very different mechanisms of action would all provide relief for migraines. We have only a basic understanding of how these drugs might work because they were discovered to help migraines by accident. Namenda is a very old medicine that has been available in Europe for over 30 years. It was used for a variety of neurological conditions, but in the US it was introduced and approved only for Alzheimer’s disease in 2003. It works by blocking an NMDA receptor, which is found in brain cells and which is responsible for letting calcium into the cells. Excessive inflow of calcium leads to many negative effects, including propagation of pain messages along the nervous system. Magnesium is a natural NMDA receptor blocker and we often add Namenda to magnesium for stronger effect. Namenda is not a very strong medication, meaning that it probably works for less than half of the patients, but it also causes fewer side effects than many other drugs. It is well tolerated even by the elderly Alzheimer patients, although like any other drug it can cause side effects, including nausea, drowsiness, and dizziness. Another problem with the drug is that some insurance companies do not pay for it because it is not approved for the prevention of migraines.
