 - Medical records indicating a stable serum creatinine variation of not more than 30, for at least 3 months prior to the screening visit Groups 2 to 4 only, as determined by the clinical investigator. The sérum creatinine had to be stable to allow for an accurate determination of the creatinine clearance and therefore allowed for correct allocation to one of the renal function groups. Subjects who were recruited into Group 1 had normal renal function. 