Infectious Disease Compendium

Foscarnet (Foscavir®)

Dosing

From the PDR

Foscarnet Induction
HSV: Equivalent to CMV: Equivalent to
CrCl 80 mg/kg/day total 120 mg/kg/day total 180 mg/kg/day total
(mL/min/kg) (40 mg/kg Q12h) (40 mg/kg Q8h) (60 mg/kg Q8h) (90 mg/kg Q12h)
>1.4 40 Q12h 40 Q8h 60 Q8h 90 Q12h
>1.0-1.4 30 Q12h 30 Q8h 45 Q8h 70 Q12h
>0.8-1.0 20 Q12h 35 Q12h 50 Q12h 50 Q12h
>0.6-0.8 35 Q24h 25 Q12h 40 Q12h 80 Q24h
>0.5-0.6 25 Q24h 40 Q24h 60 Q24h 60 Q24h
>/=0.4-0.5 20 Q24h 35 Q24h 50 Q24h 50 Q24h
<0.4 Not Recommended Not Recommended Not Recommended Not Recommended
Maintenance
CMV: Equivalent to
CrCl (ml/min/kg) 90 mg/kg/day (once daily) 120 mg/kg/day (once daily)
>1.4 90 Q24h 120 Q24h
>1.0-1.4 70 Q24h 90 Q24h
>0.8-1.0 50 Q24h 65 Q24h
>0.6-0.8 80 Q48h 105 Q48h
>0.5-0.6 60 Q48h 80 Q48h
>/=0.4-0.5 50 Q48h 65 Q48h
<0.4 Not Recommended Not Recommended

Important side effects

Cytopenias of all kinds and renal insufficiency.

Important drug interactions

Astemizole, bepridil, chloral hydrate, chloroquine, cidofovir, cisapride, clarithromycin, class i antiarrhythmic agents, class ia antiarrhythmic agents, class iii antiarrhythmic agents, cotrimoxazole, dolasetron, droperidol, enflurane, erythromycin, erythromycin/sulfisoxazole, fluconazole, fluoxetine, gemifloxacin, halofantrine, halothane, isoflurane, isradipine, levomethadyl, lidoflazine, mefloquin, mesoridazine, octreotide, pentamadine, phenothiazines, pimozide, probucol, spiramycin, sulfamethoxazole, telithromycin, terfenadine, thioridazine, tricyclic antidepressants, trimethoprim, vasopressin, venlafaxine, ziprasidone, zolmitriptan.

Rants and Screeds

Pearls

Treatment of choice

Use for:

CMV, acyclovir resistant HSV.

Don't use for

Class

Ophosphate analogue.