Over-the-counter allergy medicines like cetirizine (Zyrtec) and levocetirizine (Xyzal) have become common drugs for many people in the US who suffer from seasonal symptoms like watery eyes and sneezing, but now the FDA indicates that both drugs have a new risk.
The FDA recently published a warning about these antihistamines, saying that patients who suddenly stop taking these medicines after long-term use “may experience rare but severe itching.” The itching, which is also known as pruritus, occurred in patients who had been taking cetirizine and levocetirizine daily for a few months or even years.
The FDA estimates that 62.7 million over-the-counter packages of cetirizine and levocetirizine were bought in 2022. The same year, about 26.8 million cetirizine and levocetirizine prescriptions for both OTC and prescription products were dispensed from US outpatient pharmacies. Considering that allergies are getting worse, partly because of climate change creating longer, more intense pollen seasons, it wouldn’t be surprising if these numbers continue to climb.
The FDA decided to issue this warning after identifying 209 cases worldwide — 180 cases for cetirizine, 27 for levocetirizine and two for both — of this particular side effect reported between April 2017 and July 2023. However, there may be more cases, since these are only those that were reported to the FDA. Interestingly, even though most patients who experienced this severe itching had been taking these antihistamines for over three months, some had this reaction after less than one month of use.
Due to these findings, the FDA will now include a warning on the prescribing information for prescription cetirizine and levocetirizine. The administration is also asking that manufacturers add this warning to drug facts labels for OTC versions.
For those who dealt with this side effect, restarting the antihistamine or tapering it off after restarting often resolved the issue.
According to the FDA, the most common side effects of cetirizine and levocetirizine are fatigue, drowsiness, sore throat, cough, dry mouth, nosebleed, fever, diarrhea and vomiting.
When to contact your doctor
If you stop taking OTC cetirizine or levocetirizine and develop severe itching within a few days after you’d been using the medicine daily for several months to years, you should contact your doctor. If you plan to take these medicines for a prolonged period of time, you should also discuss the pros and cons with your doctor before starting.