Antiviral: Herpes zoster and simplex Prevention of cytomegalovirus (CMV) disease after renal transplantation
DOSE IN NORMAL RENAL FUNCTION
Herpes simplex: 500 mg twice daily for 5–10 days Herpes zoster: 1 g 3 times a day for 7 days Herpes simplex suppression: 500 mg daily in 1–2 divided doses (500 mg twice daily in the immunocompromised) Prevention of CMV disease: 1 g 3 times a day for 90 days
30–50 Dose as in normal renal function 15–30 Herpes simplex: Dose as in normal renal function Herpes zoster: 1 g every 12 hours CMV prophylaxis: 1 g every 12 hours <15 Herpes simplex: 500 mg daily Herpes zoster: 1 g every 24 hours CMV prophylaxis: 1 g every 24 hours Herpes simplex suppression: Immunocompetent – 250 mg daily Immunocompromised – 500 mg daily
DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES
CAPD                : Likely dialysability. Dose as in GFR<15 mL/min
HD                     : Dialysed. Dose as in GFR<15 mL/min post dialysis
HDF/high flux   : Dialysed. Dose as in GFR<15 mL/min post dialysis
CAV/VVHD      : Likely dialysability. Dose as in GFR=15–30 mL/min
IMPORTANT DRUG INTERACTIONS
Potentially hazardous interactions with other drugs
Ciclosporin: may alter ciclosporin levels Mycophenolate: higher concentrations of both aciclovir and mycophenolic acid on concomitant administration
ADMINISTRATION
Reconstition
–
Route
Oral
Rate of Administration
–
Comments
–
OTHER INFORMATION
Almost completely (80%) converted to aciclovir – see aciclovir monograph for further information
Bioavailability of aciclovir from 1 g oral dose of valaciclovir is 54% Mean peak aciclovir concentrations occur 1.5 hours post dose; peak plasma concentrations of valaciclovir are 4% of aciclovir levels, occur at a median of 30–60 minutes post dose, and are at or below the limit of quantification 3 hours post dose The dose quoted in the literature for CMV prophylaxis in transplant recipients is 2 g 4 times a day. However, in practice this results in severe aciclovir toxicity, especially in patients with poorly functioning grafts .