Abstract: 【Abstract】 Objective To evaluate the efficacy of acrivastine alone or in combination with loratadine in the treatment of chronic refractory urticaria. Methods From March 2017 to December 2018, a multicenter, randomized, controlled clinical study was conducted in 4 centers. Patients with chronic refractory urticaria were randomly divided into two groups, i.e., combined treatment group receiving oral acrivastine capsules 8 mg thrice a day plus oral loratadine tablets 10 mg once a day, and acrivastine alone group receiving oral acrivastine capsules 8 mg thrice a day plus a placebo 10 mg once a day. The course of treatment was 4 weeks. Visits were scheduled at baseline and after 1, 2 and 4 weeks of treatment. At the same time, clinical data were collected, and adverse events were recorded. Symptom scores were evaluated based on degree of itching, number and size of wheals, duration of each attack and number of attacks per week, and symptom score reduce index （SSRI） was used to evaluate the efficacy. Repeated measures analysis of variance and chi-square test were used to evaluate the efficacy and safety. Results Fifty-three patients in the combined treatment group and 59 in the acrivastine alone group were included in the efficacy analysis. Before treatment, there was no significant difference in symptom score or visual analogue score between the two groups. After 2 weeks of treatment, 19 patients were cured and 10 achieved marked improvement in the combined treatment group, with a response rate of 54.72%; 15 were cured and 6 achieved marked improvement in the acrivastine alone group, with a response rate of 35.59%. After 4 weeks of treatment, 23 patients were cured and 9 achieved marked improvement in the combined treatment group, with a response rate of 60.38%; 20 were cured and 2 achieved marked improvement in the acrivastine alone group, with a response rate of 37.29%. After 2 and 4 weeks of treatment, the response rates were significantly higher in the combined treatment group than in the acrivastine alone group （χ2 = 4.13, 5.96 respectively, both P < 0.05）. The SSRI significantly differed among different follow-up time points, as well as between the 2 groups （F = 8.62, 4.38 respectively, both P < 0.05）. Multivariate analysis of variance showed that SSRI was significantly higher in the combined treatment group （0.63 ± 0.05, 0.68 ± 0.05, respectively） than in the acrivastine alone group （0.47 ± 0.05, 0.51 ± 0.05, respectively） after 2 and 4 weeks of treatment （both P < 0.05）. Drug-related adverse reactions, including drowsiness, stomach upsets, headache and liver function abnormality, occurred in 7 patients in the combined treatment group, as well as in 3 in the acrivastine alone group. Conclusion Acrivastine is safe and effective for the treatment of chronic refractory urticaria, and acrivastine combined with loratadine can markedly improve the efficacy.

Key words: Urticaria, Randomized controlled trial, Drug therapy, combination, Loratadine, Acrivastine