Pharmacokinetics of emedastine difumarate, a new anti-histaminic agent in patients with renal impairment

Objective: Emedastine difumarate is a new H1 receptor antagonist with well defined pharmacokinetic and pharmacodynamic profiles in healthy volunteers. However, to date it is not known whether impaired renal function in patien ts with chronic renal insufficiency affects its pharmacokinetics and probab ly also its tolerability. Therefore, we here set out to compare the pharmac okinetics of emedastine difumarate in patients suffering from different deg rees of renal failure with a control group of healthy volunteers. Methods and results: For this purpose we conducted an open, single-centre, comparative parallel group study in patients and healthy volunteers. Emedas tine difumarate 2 mg was administered orally to the study population in sin gle and seven repetitive doses twice daily (b.i.d.). Pharmacokinetics diffe red markedly between volunteers (n = 6) and patients (n = 17). The maximum serum concentration of emedastine (C-max), area under the serum concentrati on-time curve, mean residence time and terminal disposition half-life were significantly higher in patients (P < 0.05), while time to reach C-max and apparent volume of disposition were not statistically different after singl e and repeated (steady-state) oral administrations. Blood pressure and hear t rate were also not affected by the study medication. Conclusion: The present study shows that impaired renal function alters the pharmacokinetics of emedastine in plasma. Thus, dose adjustment of emedast ine difumarate is advisable in patients with impaired renal function.