This single-dose study assessed bilastine pharmacokinetics and safety in patients with varying renal impairment.  A 20mg bilastine dose showed increased Cmax and AUC with worsening renal function, doubling in severely impaired patients compared to healthy controls.  This increase stemmed from reduced plasma and renal clearance mirroring decreased GFR.  However,  protein binding remained constant, irrespective of renal function or bilastine concentration.  Even with higher exposure in renal impairment groups, it remained below levels seen as safe in studies using higher bilastine dosages.  The rapid urinary excretion prevented accumulation, even in severe renal insufficiency.  The observed exposure in severely impaired patients stayed within safety margins established in previous studies, suggesting a dose adjustment is unnecessary.  Bilastine was well-tolerated at the 20mg dose, with only mild adverse events reported.