Long-term users of the allergy medicine Zyrtec (cetirizine) sometimes report a rare but excruciating withdrawal syndrome with itching all over their body. Jessica Misener recently wrote about her experience quitting the drug at Medium, and reports that the FDA is looking into it.
The FDA does require a note in the package insert for the prescription version of the drug, noting that “rebound pruritis” may occur (pruritis means itching) and appears as “pruritus within a few days after discontinuation of cetirizine, usually after long-term use (e.g., months to years) of cetirizine.” As for Zyrtec, which is sold over-the-counter, an FDA spokesperson told Misener that “the potential safety issue of rebound pruritus with cetirizine, levocetirizine, and hydroxyzine was posted July-September 2017, prompting an evaluation to determine the need for regulatory action.”
The withdrawal syndrome hasn’t been extensively studied, so there’s not much to say for certain about how to prevent or treat it. But a paper from the Netherlands studying about 11 people who experienced this itching suggests that it’s possible to quit the drug without side effects by tapering usage gradually, and possibly also using a corticosteroid such as prednisone during the process.
If you use Zyrtec and this whole thing makes you nervous, talk to your allergist about the best way to quit the drug or to switch to another one. The itching has not been reported as a withdrawal syndrome with Claritin or Allegra, so those medications may be an option.