Question 16

Could you comment on the use of the high-dose, short-course levofloxacin schedule in special patient subgroups such as the elderly or those with renal impairment?

Studies have been performed looking at elderly patients (60, 61), those with positive blood cultures (62) and more seriously ill with pneumonia requiring admission to hospital (50). In the geriatric population (ages from 65 to 80), no statistically significant differences in pharmacokinetics were observed between young and elderly when differences in creatinine clearance were considered. At the 500 mg dose, the mean terminal half-life of levofloxacin was 7.6 hours in the older population compared to 6 hours for the younger adults, a difference attributable to variation in renal status. The use of 750 mg levofloxacin in patients with reduced renal function has also been assessed with the finding that, in general, the full 750 mg dose can be used in all patients unless their creatinine clearance is less than 50 ml/min. Table 6 summarizes current recommendations for dose adjustment recommendations for persons with a calculated renal clearance < 50 ml/min.

Table 6. Approved renal dosing recommendations

Complicated SSSI / nosocomial pneumonia / CAP
Renal status	Initial dose	Subsequent doses
CLCR 50-80 ml/min	No dosage adjustment required
CLCR 20.49 ml/min	750 mg	750 mg q48hr
CLCR 10.19 ml/min	750 mg	500 mg q48hr
Hemodialysis	750 mg	500 mg q48hr
CAPD	750 mg	500 mg q48hr
Abbreviations: SSSI = skin and skin structure infection, CAP = community-acquired pneumonia, CLCR = creatinine clearance, q48hr = every 48 hours, CAPD = chronic ambulatory peritoneal dialysis. Adapted from reference (63).