Antiepileptics increase the risk of pneumonia among persons with Alzheimer's disease

People with Alzheimer's disease using antiepileptic drugs have twice the risk of pneumonia compared to non-users, a new study from the University of Eastern Finland shows. The risk was highest in the beginning of use, but remained on an elevated level even in long-term use. The results were published in the Journal of Alzheimer's Disease.

Of the specific drugs, phenytoin, carbamazepine, valproic acid and pregabalin were associated with an increased risk of pneumonia. Relatively few – less than 10 per cent – of the antiepileptic users had been diagnosed with epilepsy and thus, it is likely that many used these drugs for other indications, such as neuropathic pain and behavioral symptoms of dementia. Some antiepileptic drugs have sedative effects which may explain the associated risk of pneumonia.

This was the first study investigating antiepileptic use and the risk of pneumonia among persons with Alzheimer's disease. A previous study assessed the risk among younger adults and did not find a risk increase.

"Further research into whether older persons are more sensitive to the effects of antiepileptic drugs is needed. Persons with Alzheimer's disease have a higher risk of pneumonia and pneumonia-related mortality than persons without the disease. For this reason, it is important to carefully assess the risks and benefits of drug use, especially for other indications than epilepsy," Senior Researcher Heidi Taipale from the University of Eastern Finland says.

The study was based on the nationwide register-based MEDALZ study conducted at the University of Eastern Finland. For this study, 5,769 community-dwelling persons diagnosed with Alzheimer's disease who initiated antiepileptic drug use in Finland were included and compared with matched non-users of these drugs.