Introduction to the Issue

Two popular antihistamine medications, cetirizine and levocetirizine, have been found to cause intense itchiness in rare cases when their long-term use is stopped. The Food and Drug Administration (FDA) has issued a warning regarding this side effect, which has been reported by hundreds of people over the past decade.

Background on the Medications and the FDA Warning

The FDA issued its warning earlier this month, requiring manufacturers to include this side effect in the labeling of these drugs. The agency has received reports of severe, sometimes debilitating, itching after individuals stopped taking these medications. Although the underlying cause of this risk is unknown, the FDA’s evaluation supports a causal relationship between stopping cetirizine or levocetirizine and pruritus (itching).

Cetirizine and levocetirizine are antihistamine drugs that have been on the market for several years. Cetirizine was first approved as the prescription drug Zyrtec in 1995, while levocetirizine was approved as Xyzal in 2007. Both drugs are now widely available over-the-counter to treat hay fever and other allergy symptoms.

History of the Side Effect

Whispers of this side effect have been circulating for years. A 2019 study identified potential cases of severe pruritus related to cetirizine withdrawal dating back to at least 2008. A 2016 study reported similar cases in the Netherlands tied to levocetirizine. Users have also shared their experiences of unbearable itching when trying to quit these drugs on social media platforms.

The Extent of the Problem

The FDA identified 209 cases worldwide (197 in the U.S.) of new-onset pruritus after cetirizine/levocetirizine withdrawal between April 2017 and July 2023. Most people had taken the medications for over three months, often years, though cases could also occur after only one month of continuous use. Sufferers typically complained of widespread itching that required medical intervention, with some cases being so severe that they left people bedridden or led to thoughts of suicide or self-harm.

Silver Lining and Recommendations

The good news is that this side effect seems to be rare overall. About 100 million prescriptions or OTC purchases of both drugs combined were made in 2022. People with the side effect aren’t necessarily doomed to itch forever. The FDA found that 90% of people who restarted their medication resolved their itching, and about one-third of people were able to avoid a new bout of itching if they slowly weaned off the drug once restarting. Some people have also reported relief after taking a short course of corticosteroids.

If you’re a longtime user of these drugs, it’s essential to be aware of this potential side effect in case you decide to stop. People planning to take these drugs long term should discuss the benefits and risks with their doctor, who can provide advice based on your personal needs.