The U.S. Food and Drug Administration (FDA) has issued a warning that some people develop severe itching after halting long-term use of the common antihistamines cetirizine (Zyrtec) and levocetirizine (Xyzal).
“Patients did not experience itching before starting the medicines,” the FDA said in the statement. “Reported cases were rare but sometimes serious, with patients experiencing widespread, severe itching that required medical intervention.”
Millions of People Take Allergy Medications
Globally, there were 209 cases of pruritus among people who stopped taking these drugs between April 2017 and July 2023, the FDA said. Of those cases, 94 percent were in the United States, and 86 percent involved cetirizine, the active ingredient in Zyrtec.
Given such widespread use of these antihistamines in the United States alone, the worldwide risk of pruritus after stopping these drugs appears quite low, FDA data shows.
Itching Mostly Affected People Who Had Taken the Drugs for Several Months
None of the cases involved people who had experienced severe itching before starting treatment with these antihistamines.
While some people experienced pruritus when they stopped taking these antihistamines after less than one month of use, 92 percent of the cases involved people who had taken the drugs for more than three months. Pruritus typically developed one to five days after treatment was stopped, the FDA said.
Among the case reports the FDA examined, the itching was often widespread and found on many parts of the body. A total of 48 people experienced disability, three were hospitalized, and 2 had thoughts of suicide or self-harm, the FDA said.
Nine out of 10 times, the pruritus cleared up when patients resumed treatment with the antihistamine they had abruptly stopped, the FDA said.
Talk With Your Doctor About Using Allergy Medications
People should talk to their healthcare providers about taking these antihistamines, the FDA said, even if they’re using over-the-counter versions. And they should discuss the risk of pruritus with their medical provider if they plan on long-term use of these medicines, the FDA said.
“If that is the best treatment for one’s allergies, I see no reason to avoid it or to limit its use, but patients should be aware of the possibility of pruritus if they are stopping the medication after long-term use,” says Yul Ejnes, MD, an internal medicine specialist and a clinical professor of medicine at the Alpert Medical School of Brown University. “If the itching occurs, it appears that resuming the medication and tapering it slowly addresses the problem.”
One key way to identify treatment-related pruritus is based on your medical history, according to the FDA.
“The scenario would be that after stopping the medication, a patient feels an ‘all over’ itching without a rash or other reason to explain the itching, such as an allergic reaction or a skin condition,” Dr. Ejnes says.
Take Medications Only as Long as You Need Them
“For any medicine, you should use it for the shortest amount of time needed and shouldn’t stay on anything if you don’t need it,” says Purvi Parikh, MD, a clinical assistant professor of medicine and pediatrics at New York University Langone Health in New York City who specializes in infectious disease, allergies, and immunology.
If you do end up taking drugs like Zyrtec or Xyzal for a long period of time, it may be best to taper off these medicines gradually instead of stopping cold turkey, in order to minimize the already low risk of pruritus, Dr. Parikh adds.
If you’re worried about this side effect or you experience it and want to find a different way to manage your allergies or congestion, you do have alternatives, Parikh notes.
“Other options for nasal congestion or allergies are over-the-counter nasal sprays like Flonase or astepro that work well without these side effects,” Parikh says. “You can also try other long-acting antihistamines that don’t have this warning, such as Allegra or Claritin.”