Anti-dementia drugs: People taking memantine have highest risk of pneumonia

Memantine has been singled out as the riskiest drug, in a study which looked at which anti-dementia drugs put people most of risk of getting pneumonia.

The research by the University of Eastern Finland found the use of rivastigmine patches is also associated with an increased risk.

People using donepezil or galantamine had the lowest risk of pneumonia, whereas people using memantine or rivastigmine patches had a 1.6 and 1.15 times higher risk of pneumonia. However no increased risk was observed among patients using rivastigmine in capsule form.

Researchers warn that the increased risk may be even higher, as only cases of pneumonia leading to hospitalisation or death were taken into account. They concluded that doctors need to consider the increased risk of pneumonia when deciding which anti-dementia drugs to prescribe.

The study ‘Use of anti-dementia drugs and risk of pneumonia in older persons with Alzheimer’s disease’ is the first to compare the risk of pneumonia associated with different anti-dementia drugs and drug forms. The results are not likely to be explained by differences between drug molecules, as rivastigmine was associated with an increased risk of pneumonia in patch form only.

Researchers say the increased pneumonia risk among persons using memantine or rivastigmine patches may be partly explained by the fact that these medications are often used in more advanced states of dementia. All people in the study were living at home.

The study is based on data from a nationwide register-based study (MEDALZ) conducted at the University of Eastern Finland. Academics looked at 65,481 people diagnosed with Alzheimer’s disease during 2005-2011 in Finland.

No cure for Alzheimer’s diseases currently exists, but the progression of the disease can be slowed down by anti-dementia drugs, such as memantine and acetylcholinesterase inhibitors such as donepezil, galantamine, and rivastigmine.

People with Alzheimer’s disease do have an increased risk of pneumonia, and it is one of the most common causes of hospitalisation among those with Alzheimer’s disease.

The findings were published in the Annals of Medicine - http://dx.doi.org/10.1080/07853890.2016.1254349