Levofloxacin Plasma Levels After Hemodialysis
Yes, substantial amounts of levofloxacin remain in the plasma after hemodialysis, which is precisely why supplemental post-dialysis dosing is not necessary and the drug should be administered after—not before—dialysis sessions. 1, 2
Dialytic Removal and Plasma Retention
Hemodialysis removes only approximately 24% of levofloxacin from the body during a standard dialysis session, with reduction ratios ranging from 0.181 to 0.412 (meaning 58-82% remains in plasma after dialysis). 3
The dialytic clearance of levofloxacin is approximately 84 mL/min (range 62-108 mL/min), which is modest compared to the drug's large volume of distribution (103 L) and prolonged half-life in ESRD patients (34 hours). 3
The FDA label explicitly states that "neither hemodialysis nor continuous ambulatory peritoneal dialysis (CAPD) is effective in removal of levofloxacin from the body," confirming that supplemental doses after dialysis are not required. 2
Clinical Implications for Dosing
Administer levofloxacin 750-1000 mg three times weekly immediately after each hemodialysis session in ESRD patients to prevent premature drug removal while maintaining therapeutic concentrations. 1, 4
Post-dialysis administration ensures that the drug remains in the body throughout the interdialytic period, as the prolonged 34-hour half-life in ESRD patients (compared to 6-8 hours in healthy subjects) provides sustained plasma levels. 3
The substantial plasma retention after dialysis means that giving supplemental doses post-dialysis would lead to drug accumulation and potential toxicity, particularly neurotoxicity in elderly patients with renal failure. 5
Pharmacokinetic Evidence
After a 250 mg dose in ESRD patients, median peak concentrations (Cmax) of 5.2 mcg/mL are achieved, with therapeutic levels maintained for 48 hours despite one intervening dialysis session. 3
The systemic clearance in ESRD patients on hemodialysis is only 37 mL/min (compared to 175 mL/min in healthy subjects), demonstrating that non-dialytic clearance mechanisms are severely impaired and dialysis contributes only modestly to total drug elimination. 3
Critical Pitfall to Avoid
Never administer levofloxacin before dialysis, as this wastes approximately 24% of the dose and creates subtherapeutic levels immediately post-dialysis, potentially leading to treatment failure. 4, 3
The three-times-weekly dosing schedule (not daily dosing) is essential because the drug accumulates significantly in ESRD patients, with an elimination half-life 4-5 times longer than in patients with normal renal function. 3