Dementia Drugs May Increase Pneumonia Risk

Memantine increases the risk of developing pneumonia by 1.6 times.

Patients with dementia administered memantine may be at an increased risk of developing pneumonia compared with patients taking other antidementia drugs, a recent study found.

Memantine is a NMDA receptor antagonist that blocks the activity of glutamate in the brain. In high concentrations, glutamate can kill nerve cells and lead to decreased cognition. Memantine can prevent some cognitive deterioration, and can positively affect mood, behavior, and the ability to perform day-to-day activities.

These findings suggest this medication may also increase the risk of pneumonia in these patients.

Included in the study, published by Annals of Medicine, were records for 5481 patients diagnosed with Alzheimer’s disease from 2005 to 2011. Data was collected from the MEDALZ nationwide database from Finland.

In the study, scientists found that patients taking donepezil or galantamine had the lowest risk of pneumonia, while those taking memantine had 1.6 times greater risk.

They also determined that patients treated with rivastigmine patches also had a 1.5 times increased risk of pneumonia. Interestingly, the scientists did not observe any increased risk of pneumonia among patients taking rivastigmine in capsule form.

Donepezil, galantamine, and rivastigmine are all acetylcholinesterase inhibitors, which can treat the neuropsychiatic symptoms of the disease. While they do not cure or slow the disease, these drugs are able to improve cognition and behavior.

Unfortunately, the scientists said that the actual risk of developing pneumonia may be higher while taking these drugs, since the study only accounted for serious cases of pneumonia that lead to hospitalization or death. This is the first study that has investigated the potential link between pneumonia and antidementia drugs.

The scientists speculated that these findings may not potentially be explained by the differences in drug composition, since rivastigmine only increased the risk of pneumonia in the patch form, according to the study.

These findings could be associated with the disease state of the patient, since those taking memantine or rivastigmine patches typically have more advanced disease, but all patients included in the study were still living at home.

Currently, there is no cure for Alzheimer’s disease, but certain drugs can slow the progression of the disease. Patients with Alzheimer’s disease have an elevated risk of developing pneumonia, which is a common cause of hospitalization, and a leading cause of death among this population.

Although additional studies are needed, these recent findings could help scientists better understand why certain drugs increase the risk of pneumonia. This could potentially lead to new treatments that do not carry the risk of pneumonia.

Novel medications that do not elevate the risk of developing pneumonia could decrease unnecessary hospitalizations and related costs, as well as improve patients’ quality of life.