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 patients with chronic renal insufficiency affects its pharmacokinetics and probably also its tolerability. Therefore, we here set out to compare the pharmacokinetics of emedastine difumarate in patients suffering from different degrees 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. Emedastine difumarate 2 mg was administered orally to the study population in single and seven repetitive doses twice daily (b.i.d.). Pharmacokinetics differed markedly between volunteers (n = 6) and patients (n = 17). The maximum serum concentration of emedastine (Cmax), area under the serum concentration-time curve, mean residence time and terminal disposition half-life were significantly higher in patients (P < 0.05), while time to reach Cmax and apparent volume of disposition were not statistically different after single and repeated (steady-state) oral administrations. Blood pressure and heart 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 emedastine difumarate is advisable in patients with impaired renal function.