Seasonal allergy meds seem to help reader sleep better

DEAR DR. ROACH»

I’m a 58-year-old male with seasonal allergies. I often take the generic versions of Zyrtec and Claritin to deal with the symptoms. While neither of those makes me drowsy, I do sleep much better — usually longer, and I don’t wake up in the middle of the night after taking either of these medications. This is more pronounced with Zyrtec than with Claritin.

Since I sometimes don’t sleep very well, I find myself taking these drugs more often than needed.

I wonder if this is something I should discontinue. Am I sleeping longer because my sleep is less restful, similar to the effect alcohol has on sleep?

I also read an article last year that indicated that another allergy medication, Benadryl, was linked to an increased risk of dementia.

Are there any similar concerns with these allergy medications?

— K.S.

ANSWER» A 2019 study linked several commonly used drugs, including diphenhydramine (Benadryl), with dementia, when used long term. It was thought to be a property called the “anti-cholinergic” effect that was linked with dementia.

While it remains unclear whether these drugs truly increase the risk of dementia or whether they are commonly used by people with early symptoms of dementia, many physicians, including myself, think twice now about prescribing these medications long term.

Fortunately, neither cetirizine (Zyrtec) nor loratadine (Claritin) are anticholinergic.

Claritin can’t even get into the brain, due to a system called the bloodbrain barrier, so is very safe from both dementia and drowsiness.

Zyrtec can get into the brain and causes drowsiness in a minority of people, and in my experience, far fewer than diphenhydramine does.

Since your better sleep seems to occur even with Claritin, I suspect it may be successful treatment of the allergy symptoms, perhaps making it easier to breathe at night, that is responsible for the longer sleep, and would not recommend you change as long as you are feeling well rested in the morning.

I would choose either Zyrtec or Claritin rather than switching.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.

Keith Roach