The present study compared the pharmacodynamic activity of bilastine administered under fasting and fed conditions in healthy volunteers.

The study involved 24 healthy subjects who received once-daily oral bilastine 20 mg for 4 days under fasting and fed conditions, with a 7-day washout period. It measured the bilastine plasma concentrations for 24-hour after the first and fourth doses in each period. It also assessed the pharmacodynamic activity by wheal and flare surface inhibition and itching after intradermal injection of histamine 5 μg.

The study observed:

• Decrease in bilastine 20 mg exposure after administration under fed vs. fasting conditions.
• Yet, the antihistaminic effect of bilastine 20 mg remained unaltered by food. 
• No significant difference in the maximum effect and duration of action of bilastine between fasting and fed conditions on day 1, as assessed by the wheal and flare surface inhibition, with only a short 30-min delay in the onset of wheal inhibition.
• No significant effect on bilastine′s pharmacodynamic effects under fasting or fed conditions at a steady state (day 4).

This study shows that the pharmacokinetic interaction of bilastine with food does not cause a significant reduction of its peripheral antihistaminic efficacy. Despite a slight delay in the onset of action on the first treatment day, the global clinical efficacy of bilastine remains unaffected by coadministration with food.

Source: Coimbra J, Puntes M, Gich I, et al. Lack of clinical relevance of bilastine-food interaction in healthy volunteers: a wheal and flare study. Int Arch Allergy Immunol. 2022 Jun 14:1-10.