To have my updated allergy testing done, my allergist had me stop taking antihistamine medications prior to the appointment to ensure we were gathering the most accurate scratch test results. That week, I vividly recall struggling to fall asleep, kept awake by intense itching all over my body. I scratched so furiously that I left marks on my skin, unsure that I’d be able to tough it out until my upcoming clinic visit.
Surely it was all in my head, right? I just needed to stop thinking about it and the feeling would magically dissipate. Desperate for the unpleasantness to end, even talked with my therapist about how to practice putting my mind over matter.
Well, it seems I chalked up this debilitating itchiness to anxiety a little too quickly, as research suggests that there may have been a physiological explanation for my discomfort.
Cetirizine, a second-generation antihistamine sold under the brand name Zyrtec, is an over the counter medication used for 24-hour allergy relief from hay fever and hives. Antihistamine medications like Zyrtec relieve allergy symptoms by blocking histamines from attaching to H1 receptors in the body, disrupting the inflammatory response.
Zyrtec is considered safe for daily consumption, but prolonged use of such antihistamine medications has been linked to an ironic side effect.
In 2017, the Food and Drug Administration (FDA) found that the sudden discontinuation of cetirizine may result in pruritus — Meaning that stopping Zyrtec cold turkey after more than 6 months of use can cause generalized itching! This side effect is harmless, but undeniably uncomfortable, and can take days to even weeks to fully subside.
So, the medication used to treat itchiness can actually cause itchiness?
It turns out this phenomenon is relatively common in medicine! Let’s use hangovers as an example.
Alcohol intoxication typically results in drowsiness and disinhibition, whereas alcohol withdrawal (e.g., sobering up) often leads to insomnia, irritability, anxiety, headaches, and a general sense of discomfort. It’s like a teeter-totter effect — As our bodies strive to regain balance, they can “overshoot” and produce these opposing symptoms.
Withdrawal symptoms can be alleviated by gradually weening yourself of the substance, allowing the body more time to adapt to the lowing dose. That’s where the phrase “Hair of the Dog” comes in. Feeling hungover? Having another drink might help ease your symptoms.
However, Zyrtec has not included a specific weaning schedule in their drug information. Board certified allergist, Dr. Rubin, suggests consulting with your doctor about how to best taper off the medication to avoid such side effects.
So, it turns out my mind might not have been playing tricks on me after all. For as often as I have to reassure my anxious brain that I’m not experiencing allergy symptoms, it was quite validating to learn that this case wasn’t just in my head.
Disclaimer
The contents of this article are intended for educational purposes only, and should not be substituted for medical or professional advice. Please contact a licensed medical or mental health professional for more information.
References
Chung, A. H., La Grenade, L., & Harinstein, L. M. (2019). Pruritus after discontinuation of cetirizine. Therapeutic Advances in Drug Safety, 10. https://pubmed.ncbi.nlm.nih.gov/31308927/
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