The risk was highest at the beginning of use but remained on an elevated level even in long-term use, according to a study from the University of Eastern Finland.
“It is important to carefully assess the risks and benefits of drug use”
The study results, published in the Journal of Alzheimer’s Disease, suggested that phenytoin, carbamazepine, valproic acid and pregabalin were associated with an increased risk of pneumonia.
The researchers noted that relatively few – less than 10% – of the antiepileptic users had been diagnosed with epilepsy.
Therefore, they said it was likely that many were using the drugs for other indications, such as neuropathic pain and behavioural symptoms of dementia.
Some antiepileptic drugs have sedative effects which may explain the associated risk of pneumonia, suggested the study authors.
The study was based on the university’s nationwide register-based MEDALZ study.
It involved 5,769 patients diagnosed with Alzheimer’s disease living in the community who initiated antiepileptic drug use and compared them with matched non-users of these drugs.
The authors said theirs was the first study to specifically investigate antiepileptic use and the risk of pneumonia among persons with Alzheimer’s disease.
They highlighted that a previous study had assessed the risk among younger adults and did not find a risk increase.
Senior researcher Heidi Taipale said: “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,” she said.
“For this reason, it is important to carefully assess the risks and benefits of drug use, especially for other indications than epilepsy,” she added.