I know I've harped on this subject before, but
please take note of the side effects of diphenhydramine on folks over the age of 65.
Diphenhydramine Side Effects
Evidence suggests diphenhydramine may result in serious side effects in adults ages 65 and older.5 These are in addition to the side effects everyone else can experience. The older you are, the greater the risk of adverse effects.
Fall Risk
Diphenhydramine can cause decreased reaction times and dizziness.
In older people with other medical problems or physical impairments, this may lead to falls or accidents, especially while getting up to urinate at night. The potential for bone fractures is a notable concern.
Cognitive Impairment and Dementia
Antihistamines like diphenhydramine can have anticholinergic effects as well. This means that the medication acts on the signaling chemical called acetylcholine, which can have important consequences.
One of the more significant ones is cognitive impairment, such as confusion, that's similar to what occurs with dementia or delirium.6
Growing evidence suggests chronic use of these medications may also be associated with the long-term development of dementia.7
Drying Effects
There may also be “drying effects.” These may manifest as:8
Dry mouth
Constipation
Blurred vision
Urinary retention
Urinary retention may increase the risk of developing
urinary tract infections (UTIs) or affect kidney function.
Contraindications
Diphenhydramine can be especially dangerous and should not be used for any reason by older adults with history of:
Closed-angle glaucoma
Constipation
Urinary retention
Asthma
Severe liver disease
Summary
The older you are, the greater the risk of adverse effects from diphenhydramine. It generally should not be used as a sleep aid in those ages 65 and older.