Think twice about popping a pill before bed. Over-the-counter sleeping drugs and hayfever treatments may increase chances of Alzheimer’s disease, according to a new study published in the journal JAMA Internal Medicine on Monday. Drugs including sleeping aid Nytol and anti-allergy pills Benadryl and Piriton contain "anticholinergic" blocking effects, and if taken in higher doses, can raise the risk of developing Alzheimer's and other forms of dementia. Anticholinergic drugs block the nervous system chemical transmitter acetylcholine, which people diagnosed with Alzheimer's disease often lack. But don't stop therapy just yet, according to Professor Shelly Gray, the director of the geriatric pharmacy program at the University of Washington School of Pharmacy who led the U.S. study. Patients should consult their healthcare providers while doctors should regularly review their older patients' drug regimens and look for opportunity to use fewer anticholinergic medications at lower doses, Gray added. While more research is needed to understand the potential dangers, the study is the first to reveal a dose response linking greater use of the medicines with an increased risk of dementia.