In the treatment of chronic spontaneous urticaria, using a high dose of second-generation H1-antihistamines (sgAHs) (up to 2 times the regular dose) may be more beneficial than a regular dose, according to a systematic review and meta-analysis of randomized clinical trials. The effectiveness and safety of high-dose sgAHs against standard-dose sgAHs to relieve urticaria were evaluated by the researchers.

Electronic databases such as Medline, Embase, PsycInfo, Cochrane databases, and Web of Science were explored for relevant literature search. Manual searches were also done on bibliographies. The quality of randomized controlled trials (RCTs) was determined with the aid of Cochrane Risk of Bias Tool for measuring the risk of bias.

Screening of the studies, extraction of data, and risk of bias examination were done by 2 reviewers. Each article's response rate, number of side effects, somnolence, and withdrawal because of side effects were assessed. To calculate the effectiveness and safety of the therapy, data were pooled and evaluated. For data synthesis, RevMan (V5.3) software was utilized.

Overall, 7 out of 13 eligible studies were identified for the meta-analysis. High-dose sgAHs were associated with a considerably greater response rate as opposed to the standard dose (risk ratio [RR] 1.13), according to the pooled meta-analyses. High dosages of sgAHs were linked to noticeably greater somnolence rates when contrasted to the standard dose (risk difference [RD] 0.05). Between standard-dose and high-dose treatments, there was no discernible difference in the number of adverse events or withdrawals caused by adverse events.

In the treatment of chronic spontaneous urticaria, a high dosage of sgAHs could be more efficient than a standard dosage. Except for somnolence, which exhibited a dose-dependent incidence in certain studies, standard-dose and high-dose sgAHs depicted identical side effects. However, it is important to use caution when interpreting the meta-analysis results due to the limited number of studies.