Abstract
Chronic spontaneous urticaria (CSU) affects 1% of the world population and also their quality of life, and 50% of these patients are refractory to H1-antihistamines. Omalizumab is a humanized monoclonal anti-IgE antibody that binds with free IgE antibodies and reduces the circulating levels of free IgE. This reduction in free IgE prevents mast-cell degranulation. The EAACI/GA2LEN/EDF/WAO guidelines recommend omalizumab as the third-line of therapy as an add-on to antihistamines. The recommended dose of omalizumab is 300 mg, 4 weekly in the management of CSU refractory to standard of care with H1-antihistamines in adults and adolescents ≥12 years of age. In some patients, a dose of 150 mg may be acceptable. Omalizumab has a good safety profile. However, due to the biologic nature of the drug, all patients administered omalizumab must be observed for 2 h after administration for anaphylactoid reactions. There have been no studies on the effect of impaired renal or hepatic function on the pharmacokinetics of omalizumab. While no particular dose adjustment is recommended, omalizumab should be administered with caution in these patients.