Although there are millions of people with Alzheimer’s disease (AD) and there is extensive research into the disease, the causes of Alzheimer’s disease are still not fully understood. Therefore it has been difficult to develop drugs that effectively treat Alzheimer’s. There are some pharmaceutical drugs that have proved, through clinical trials, to have a positive effect on AD at its various stages. The FDA has approved 2 main types of drugs for use by Alzheimer’s patients.
- Cholinesterase inhibitors help restore cognitive functioning by increasing the amount of the important brain signaling molecule acetylcholine. The decline in cognitive functioning associated with Alzheimer’s is thought to be related to a build up of amyloid proteins, or plaques, that interrupt the brain’s ability to transmit messages successfully. Having more acetylcholine increases the brain’s ability to transmit messages. There are 4 FDA-approved cholinesterase inhibitors. The commonly prescribed ones are donezepil HCL (Aricept), rivastigmine (Exelon), and galantamine (Razadyne). Tacrine (Cognex) was the first drug approved by the FDA for Alzheimer’s treatment, however, it is rarely prescribed due to its harsh side effects. These are typically prescribed for early stage or mild AD and can have a variety of interactions with other drugs, which factor in doctors’ decisions about which one is preferred for each individual.
- The other FDA-approved Alzheimer’s drug is memantine (Nameda). It is known as an NMDA antagonist and is typically prescribed for patients suffering from more severe AD. It increases glutamate levels in the brain while blocking NMDA receptors. NMDA receptors in the brain are critical for the transmission of messages. When they do not function adequately, the results often include severe cognitive decline. NMDA agonists, like memantine, work by blocking the NMDA receptors, essentially protecting them from potentially harmful toxins while allowing glutamate levels to increase and activate them.
Recent studies show that some medications for high blood pressure can be beneficial effect for those with Alzheimer’s disease. The group of drugs known as angiotensin receptor blockers, which include candesartan (Atacand), irbesartan (Avapro), losartan (Cozaar), and valsartan (Diovan), lower the risk of contracting Alzheimer’s by 19%. They also reduce the chance of Alzheimer’s sufferers dying or being admitted to a care facility by 67%. Research also shows that menopausal women who have used hormone replacement therapy (HRT) for extended periods of time show a decreased risk of developing Alzheimer’s.
Some steroids and non-steroidal anti-inflammatory drugs prescribed for arthritis have been reported to provide Alzheimer’s improvements, as have anti-depressants and, in some cases, antibiotics. The benefits of prescribing these drugs is derived, primarily, from the increased brain functioning that is associated with clearing up other physical or mental problems, like depression, pain and infections. Alzheimer’s patients tend to experience increased agitation as a symptom and alleviating physical or mental discomfort can help reduce this agitation.
References:
Khachaturian AS, Zandi PP, Lyketsos CG, Hayden KM, Skoog I, Norton MC, Tschanz JT, Mayer LS, Welsh-Bohmer KA, Breitner JC. Antihypertensive medication use and incident Alzheimer disease: the Cache County Study. Arch Neurol. 2006 May;63(5):686-92.
Zandi PP, Carlson MC, Plassman BL, Welsh-Bohmer KA, Mayer LS, Steffens DC, Breitner JC; Cache County Memory Study Investigators. Hormone replacement therapy and incidence of Alzheimer disease in older women: the Cache County Study. JAMA. 2002 Nov 6;288(17):2123-9.
