91ԭ

Skip to content
Join our Newsletter

Your Good Health: Newer antihistamines can cause drowsiness

In large studies, 11% to 14% of people taking Zyrtec reported drowsiness, compared to 6% of people who had drowsiness on an inactive pill.
web1_dr-keith-roach-with-bkg
Dr. Keith Roach

Dear Dr. Roach: Is Zyrtec safe to take for 75 year olds?

M.D.

Cetirizine (Zyrtec) is a “newer generation” antihistamine with fewer side effects than older antihistamines, like diphenhydramine (Benadryl). Even so, some people will experience drowsiness with this medicine. In large studies, 11% to 14% of people taking Zyrtec reported drowsiness, compared to 6% of people who had drowsiness on an inactive pill.

Older adults are even more likely to develop drowsiness, so it’s recommended not to exceed 5 mg (half the dose for young adults) for people aged 77 or older.

The reason for the lower dose is that older adults tend to have a slower metabolism, so the 5-mg dose is roughly equivalent to the 10-mg dose for younger people.

One problem that can happen when someone takes an antihistamine every day is that if they stop it, they can develop severe itching. To avoid this, don’t take it every day unless you really need it, and even then, try to go without it periodically. If you are taking Zyrtec for chronic allergy symptoms of the nose, you might have better results with a nasal steroid, like fluticasone (Flonase).

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected]