FDA Requires Warning About Rare but Severe Itching After Stopping Long-Term Use of Oral Allergy Medicines Cetirizine or Levocetirizine (Zyrtec, Xyzal, and Other Trade Names)

Why It Matters

The warning highlights a previously unrecognized withdrawal effect for widely used OTC allergy medicines, potentially affecting millions of users and prompting clinicians to reassess long‑term treatment plans. It also underscores the need for patient education and monitoring when discontinuing antihistamines.

Key Takeaways

• FDA adds pruritus warning for cetirizine, levocetirine discontinuation
• 209 cases reported, 197 in U.S., since 2017
• Most incidents after >3 months daily use, median 33 months
• Restarting medication resolves itching in ~90% of cases
• OTC purchases exceeded 60 million packages in 2022

Pulse Analysis

The second‑generation antihistamines cetirizine and its active enantiomer levocetirine have become household staples for seasonal and perennial allergy relief, with U.S. consumers purchasing more than 60 million OTC packages in 2022 alone. Their once‑daily dosing and favorable safety profile have encouraged long‑term use, especially among patients with chronic urticaria. However, the FDA’s recent safety communication reveals a withdrawal‑related phenomenon—severe pruritus—that emerges days after discontinuation. This development challenges the long‑standing perception that these agents are free of rebound effects and forces a reevaluation of how clinicians and pharmacists advise sustained therapy.

Analysis of the FDA Adverse Event Reporting System shows 209 global reports of post‑cessation itching, 197 of which originated in the United States, with the majority linked to OTC products. Most affected individuals had been using the antihistamines for more than three months, and the median exposure spanned 33 months, suggesting a dose‑duration relationship. Although the incidence is low relative to the tens of millions of packages sold, the seriousness of outcomes—including hospitalization and, in rare cases, suicidal ideation—justifies a label update. The new warning advises clinicians to discuss the risk before initiating chronic therapy and to consider tapering strategies when discontinuation is planned.

The FDA’s action illustrates the growing importance of post‑marketing surveillance in uncovering rare adverse events for widely available OTC drugs. For manufacturers, adding a pruritus warning to both prescription inserts and Drug Facts Labels may influence consumer confidence and could modestly curb sales of long‑term antihistamine regimens. Healthcare providers will likely incorporate screening questions about duration of use and educate patients on potential withdrawal symptoms, mirroring practices traditionally reserved for prescription‑only agents. Ongoing research into the underlying mechanism—whether immunologic or neuro‑cutaneous—will be essential to refine guidance and possibly develop tapering protocols that mitigate the itching risk.