Chronic hives may be effectively treated with high dose Xyzal or Clarinex

Chronic urticaria, or “hives”, can be very bothersome and may not improve with usual doses of antihistamines used for other conditions (e.g., nasal allergies). Patients often ask whether it would be safe and helpful to take 2-3 times the usual doses of antihistamines such as Clarinex or Xyzal. In a recent study, increasing the dose of Xyzal from the usual 5 mg up to 20 mg per day did result in markedly improved control of hives. Increasing Clarinex similarly was also moderately helpful. There was no increase in drowsiness or any other side effect with either medication. So, it may be safe to take higher doses of these medications when needed for severe chronic hives, though we would recommend starting with lower doses and increasing only if approved by your doctor.

J Allergy Clin Immunol 2010;125:676-82. The effectiveness of levocetirizine and desloratidine in up to 4 times conventional doses in difficult-to-treat urticaria. Staevska M, Popov TA, Kralimarkova T, Lazarova C, Kraeva S, Popova D, Church DS, Dimitrov V, Church MK (Bulgaria, UK, Germany)