Entecavir Administration in Patients with Impaired Renal Function
Entecavir requires dose adjustment when creatinine clearance falls below 50 mL/min, with specific dosing based on both renal function and prior lamivudine exposure status. 1
Route and Timing of Administration
Entecavir must be administered orally on an empty stomach to ensure optimal absorption, as food decreases both peak concentration (Cmax) by 44-46% and overall drug exposure (AUC) by 18-20%. 2
The medication is available as 0.5 mg and 1 mg tablets, which can be taken without regard to specific time of day but should be consistently timed. 2
Dosing Based on Treatment History and Renal Function
For Nucleoside-Naïve Patients (No Prior Lamivudine Treatment)
Standard dose: 0.5 mg once daily 1
Renal impairment adjustments for 0.5 mg dosing: 1
- CrCl ≥50 mL/min: 0.5 mg every 24 hours
- CrCl 30-49 mL/min: 0.25 mg every 24 hours OR 0.5 mg every 48 hours
- CrCl 10-29 mL/min: 0.15 mg every 24 hours OR 0.5 mg every 72 hours
- CrCl <10 mL/min or hemodialysis or CAPD: 0.05 mg every 24 hours OR 0.5 mg every 7 days
For Lamivudine-Refractory or Resistant Patients
Standard dose: 1 mg once daily 1
Renal impairment adjustments for 1 mg dosing: 1
- CrCl ≥50 mL/min: 1 mg every 24 hours
- CrCl 30-49 mL/min: 0.5 mg every 24 hours OR 1 mg every 48 hours
- CrCl 10-29 mL/min: 0.3 mg every 24 hours OR 1 mg every 72 hours
- CrCl <10 mL/min or hemodialysis or CAPD: 0.1 mg every 24 hours OR 1 mg every 7 days
Critical Considerations for Renal Impairment
Dose adjustments should be calculated using ideal (lean) body weight when determining creatinine clearance. 1
For hemodialysis patients, administer entecavir after the dialysis session when using weekly dosing schedules. 1
Entecavir is substantially excreted by the kidney (62-73% via glomerular filtration and tubular secretion), making dose adjustment essential in renal impairment to prevent drug accumulation and toxicity. 2
A 4-hour hemodialysis session removes approximately 13% of an entecavir dose, which is insufficient to eliminate the need for dose adjustment. 2
Special Population Warnings
In liver transplant recipients receiving immunosuppressants that affect renal function (cyclosporine or tacrolimus), renal function must be carefully monitored both before and during entecavir treatment, as these medications can further compromise renal clearance. 2
Elderly patients require particular attention to renal function monitoring because age-related decline in kidney function increases the risk of toxic reactions. 2
Monitoring Requirements
Creatinine clearance should be assessed before initiating therapy and monitored periodically during treatment to ensure appropriate dose adjustments are maintained. 1, 2
Hepatic function must be monitored closely for at least several months after discontinuation due to risk of severe acute exacerbations of hepatitis B. 2