Oral Sedation with Midazolam and Diphenhydramine Compared with Midazolam Alone in Children Undergoing Magnetic Resonance Imaging

Background: The purpose of this study was to compare the safety and efficacy of oral midazolam and midazolam-diphenhydramine combination to sedate children undergoing magnetic resonance imaging (MRI).

Methods: We performed a prospective randomized double-blind study in 96 children who were randomly allocated into two groups. Group D received oral diphenhydramine (1.25 mg x kg(-1)) with midazolam (0.5 mg x kg(-1)), and Group P received oral placebo with midazolam (0.5 mg x kg(-1)) alone. Sedation scores, onset and duration of sleep were evaluated. Adverse effects, including hypoxemia, failed sedation, and the return of baseline activity, were documented.

Results: Diphenhydramine facilitated an earlier onset of midazolam sedation (P < 0.01), and higher sedation scores (P < 0.01). In children who received midazolam alone, 20 (41%) were inadequately sedated, compared with 9 (18%) children who received midazolam and diphenhydramine combination (P < 0.01). Time to complete recovery was not significantly different between the two groups.

Conclusions: Our study indicates that the combination of oral diphenhydramine with oral midazolam resulted in safe and effective sedation for children undergoing MRI. The use of this combination might be more advantageous compared with midazolam alone, resulting in less sedation failure during MRI.