Background and objectives: Since little is known regarding the pharmacokinetics of voriconazole in renally impaired patients, two prospective, open-label, parallel-group volunteer studies were conducted to estimate the effect of renal impairment on the pharmacokinetics of oral voriconazole and intravenous voriconazole solubilized with sulphobutylether-beta-cyclodextrin (SBECD), respectively.
Methods: In study A, male subjects with no (n = 6), mild (n = 6), moderate (n = 6) or severe (n = 6) renal impairment received one 200 mg dose of oral voriconazole. Voriconazole plasma levels were periodically assessed until 48 hours post-dose. In study B, male subjects with no (n = 6) or moderate (n = 7) renal impairment received multiple doses of intravenous voriconazole solubilized with SBECD (6 mg/kg twice daily [day 1] then 3 mg/kg twice daily [days 2-6] followed by a final dose of 3 mg/kg on the morning of day 7) at an infusion rate of 3 mg/kg/h. Voriconazole plasma levels were periodically assessed until 36 hours following the final dose. Pharmacokinetics were determined by non-compartmental methods.
Results: The pharmacokinetics of voriconazole were unaffected in subjects with any degree of renal impairment in both studies. In study B, clearance of SBECD was proportional to creatinine clearance (r2 = 0.857). Although two subjects had >30% increase in serum creatinine from baseline, these changes did not correlate with SBECD trough levels (r2 = 0.053). The majority of subjects with moderate renal insufficiency were able to tolerate 7 days of intravenous voriconazole solubilized with SBECD.
Conclusion: These data suggest that renal impairment does not affect the pharmacokinetics of voriconazole. Furthermore, in subjects with moderate renal impairment, there is a strong linear correlation between SBECD clearance and creatinine clearance, and elevated SBECD levels do not necessarily correlate with increased serum creatinine levels (an indicator of worsening renal function).