The FDA warns about the potential for rare but severe itching after discontinuation of cetirizine or levocetirizine for both over-the-counter (OTC) and prescription drug products (here). The FDA says, ”[t]he itching, also called pruritus, has been reported in patients who used these medicines daily, typically for at least a few months and often for years. Patients did not experience itching before starting the medicines.” So it appears that long-term usage is more likely to cause an adverse event. Because of this severe adverse event, the FDA will be adding a warning to the prescription drug products’ labeling as well as modifying OTC products’ Drug Facts labeling to include a warning.
The FDA says, “[t]he underlying mechanism for this risk is unknown, but our evaluation supports a causal relationship between stopping cetirizine or levocetirizine and pruritus.” According to the FDA notice, “[e]ffective treatments for pruritus have not been evaluated”; however, it seems that restarting the medication can relieve the itch, and slowly tapering off usage of the drug after a restart has been successful in some patients. The pruritus usually starts a few days after discontinuation of the medication. In some individuals, the pruritus is so severe that it requires medical intervention.
Pharmacists and other healthcare providers should be aware of this rare adverse event in order to assist patients who report experiencing pruritus after discontinuation of these medications and advise them to seek medical attention if the symptoms are severe. Patients should report adverse events to the FDA or have their healthcare provider send the appropriate notification to the Agency.
