Table 2.

Summary of articles dealing with antihistamine treatment.

Study	Design	Objective	Subjects (Age)	Methods	Results
Merenstein et al., 2006 [26]	double-blind, randomized, controlled clinical trial	to evaluate the efficacy of diphenhydramine hydrochloride therapy in children with frequent nocturnal awakenings	44 infants (6 to 15 months)	parental reports	diphenhydramine no more effective than placebo
Ghanizadeh et al., 2013 [27]	randomized placebo- controlled	to investigate the efficacy of hydroxyzine on sleep bruxism in children vs. placebo	30 children (4–12 years)	VAS and CGI-S at baseline and 4-week post treatment	significant reduction in bruxism severity with hydroxyzine treatment, with respect to placebo
Wesselhoeft et al., 2021 [28]	descriptive study	to investigate the use of melatonin, z-drugs and sedating antihistamines among Scandinavian children and young adults	all Scandinavian children (5–24 years)	public databases from Sweden, Norway, and Denmark	annual prevalence of sedating antihistamine use was highest in Sweden, 13/1000 in 2018; 7.5/1000 in Norway and 2.5/1000 in Denmark. Melatonin the most commonly used hypnotic.

CGI-S = clinical global impression severity; VAS = visual analogue scale.