Oral bioavailability of desloratadine is unaffected by food.

Objective: To determine the effect of coadministration of food on the bioavailability of oral desloratadine.

Design: A randomised, open-label, single dose crossover study in which healthy adults received a single, oral dose of desloratadine 7.5mg, 50% greater than the recommended dose of 5mg, under fed or fasted conditions and were then crossed over to receive the other treatment regimen.

Participants: 18 healthy volunteers (11 men, 7 women) aged from 18 to 43 (mean 29) years and weighing 54 to 104 (mean 76.4) kg were enrolled and completed this study.

Main Outcome Measures: C(max), AUC(S) and AUC(infinity ).

Results: Maximum mean plasma concentration (C(max)) was 3.53 microg/L in fed compared with 3.30 microg/L in fasted participants. Area under the plasma concentration-time curve from time 0 to time of final quantifiable sample (AUC(S)) mean values were 61.0 microg/L x h in fed and 61.9 microg/L x h in fasted participants. Fed individuals had mean AUC extrapolated to infinity (AUC(infinity )) of 62.5 microg/L x h compared with 63.5 microg/L x h in fasted participants. None of these differences between the fed and fasted state was statistically significant. The most frequently reported adverse event was headache. There were no statistically significant changes in ECG parameters.

Conclusion: The results of this study indicate that food has no effect on the oral bioavailability of a single oral dose of desloratadine 7.5mg.