Ganciclovir
Ganciclovir. Acyclic guanosine analog — phosphorylated to triphosphate by viral UL97 (CMV) → competitive substrate + chain-terminator for CMV… Oral half-life 3.6 h.
Acyclic guanosine analog — phosphorylated to triphosphate by viral UL97 (CMV) → competitive substrate + chain-terminator for CMV DNA polymerase. Used for CMV infection in transplant + HIV. IV form; valganciclovir is the oral prodrug.
PK: THE LARGEST SINGLE ERROR FOUND IN THIS CATEGORY. F 0.6 is verbatim in the cited paper, but that paper dosed ORAL VALGANCICLOVIR ONLY, so 60% is the yield of ganciclovir from the prodrug and belongs on the valganciclovir record. Oral GANCICLOVIR capsules average 6-9% (PMID:9110063), so the stored value over-predicted oral exposure roughly eight-fold; the stated lower endpoint is now carried. The intravenous half-life of 4 h was invented — the nearest numeral in that abstract is a Tmax of 4.3 h in SEVERE RENAL IMPAIRMENT — and that study had no intravenous arm at all. Both routes now share one disposition half-life, 3.60 h from Sommadossi 1988 (PMID:2847287) at normal renal function, and V 34 L is 0.48 L/kg from PMID:1662377. ka 0.7 /h dropped: the old citation own model is "zero-order input and first-order elimination", so a first-order rate had no home in it.
Pharmacokinetics
- Oral — t½ 3.6 h · F 6% · Vd 34 L
- IV — t½ 3.6 h · F 100% · Vd 34 L
Sources: PMID:12189361, PMID:9110063, PMID:2847287, PMID:1662377