The U.S. Food and Drug Administration (FDA) has issued an alert regarding the potential for severe itching, known as pruritus, in patients who abruptly discontinue long-term use of cetirizine (Zyrtec) and levocetirizine (Xyzal). These commonly prescribed antihistamines are used to treat seasonal and year-round allergies in adults and children aged 2 and older, as well as chronic hives in patients 6 months and older. However, the FDA warns that some patients who have used these medications for months or years and then stop treatment may experience rare but severe cases of itching requiring medical attention. This issue has prompted the agency to update prescription and over-the-counter labels to include a warning about this condition. The FDA’s warning highlights the importance of consulting healthcare professionals before discontinuing therapy, especially for patients on long-term treatment. The agency reports that 209 cases have been submitted globally since April 2017, with 197 occurring in the U.S., though the number is likely an underrepresentation due to the rarity of such incidents. Medical professionals are advised to evaluate patients who experience these symptoms after stopping medication and to consider restarting the therapy as a potential solution. The FDA’s advisory also underscores the necessity for patients to discuss the risks and benefits of prolonged use with their healthcare providers. In addition to severe itching, common side effects of cetirizine and levocetirizine include fatigue, drowsiness, cough, dry mouth, fever, sore throat, nosebleeds, and gastrointestinal issues such as diarrhea and vomiting. While these medications are highly effective in alleviating allergy symptoms, the FDA emphasizes that the risk of sudden discontinuation is extremely rare and should not deter patients from using these drugs as directed. The warning is also supported by medical experts such as Dr. Marc Siegel, who notes that the severe itching following discontinuation may be due to accelerated histamine release when the blocker is stopped. The Consumer Healthcare Products Association also supports the FDA’s guidance, stating that OTC manufacturers will comply with any necessary label updates. Opella, the manufacturer of Xyzal, reaffirmed its commitment to the safety of its product, stating that this is a rare reaction and that the medication is safe when used as directed. Patients are encouraged to consult healthcare professionals before making any changes to their medication regimen, as abrupt cessation can pose health risks despite the effectiveness of these antihistamines in treating allergy symptoms.