Famciclovir Dosage

Generic name: famciclovir
Brand name: Famvir
Drug class: Purine nucleosides

Medically reviewed by  A Ras MD.

Recommended Adult Dosing

Dosage forms:  TAB: 125 mg, 250 mg, 500 mg

Genital HSV, immunocompetent pts

[*1st episode]

Dose: 250 mg PO tid x7-10 days; Info: may extend tx if not healed after 10 days

[recurrence]

Dose: 1000 mg PO bid x1 day; Start: ASAP w/in 6h of sx onset; Alt: 500 mg PO x1, then 250 mg PO bid x2 days; 125 mg PO bid x5 days

[suppression]

Dose: 250 mg PO bid; Info: reassess tx need at 1y

Genital HSV, immunocompromised pts

[*1st episode]

Dose: 500 mg PO bid x7-10 days; Start: ASAP w/in 48h of sx onset

[recurrence]

Dose: 500 mg PO bid x5-10 days; Start: ASAP w/in 48h of sx onset

[*suppression]

Dose: 500 mg PO bid; Info: reassess tx need at 1y

Orolabial HSV, immunocompetent pts

[recurrence]

Dose: 1500 mg PO x1; Start: ASAP after sx onset

Orolabial HSV, immunocompromised pts

[*1st episode]

Dose: 500 mg PO bid x5-10 days; Start: ASAP w/in 48h of sx onset

[recurrence]

Dose: 500 mg PO bid x7 days; Start: ASAP w/in 48h of sx onset

[*suppression]

Dose: 500 mg PO bid; Info: reassess tx need at 1y

Herpes zoster (shingles)

[500 mg PO tid x7 days]

Start: ASAP w/in 72h of rash onset, maximum efficacy w/in 48h

Renal dosing

[genital HSV, immunocompetent pts, 1st episode]

renal impairment: consider decr. usual dose and/or frequency

HD: consider decr. usual dose and/or frequency; consider supplement if next maint. dose not due right after dialysis; PD: not defined

[genital HSV, immunocompetent pts, recurrence]

CrCl 40-59: 500 mg bid x1 day; CrCl 20-39: 500 mg x1; CrCl <20: 250 mg x1

HD: 250 mg x1 after dialysis; no supplement; PD: not defined

[genital HSV, immunocompetent pts, suppression]

CrCl 20-39: 125 mg bid; CrCl <20: 125 mg qd

HD: 125 mg 3x/wk after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: not defined

[orolabial HSV, immunocompetent pts, recurrence]

CrCl 40-59: 750 mg x1; CrCl 20-39: 500 mg x1; CrCl <20: 250 mg x1

HD: 250 mg x1 after dialysis; no supplement; PD: not defined

[genital or orolabial HSV, immunocompromised pts]

CrCl 20-39: 500 mg qd; CrCl <20: 250 mg qd

HD: 250 mg 3x/wk after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: not defined

[herpes zoster (shingles)]

CrCl 40-59: 500 mg bid; CrCl 20-39: 500 mg qd; CrCl <20: 250 mg qd

HD: 250 mg 3x/wk after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: not defined

Hepatic dosing

mild-moderate impairment: no adjustment; severe impairment: not defined

Recommended Peds Dosing

Dosage forms:  TAB: 125 mg, 250 mg, 500 mg

Genital HSV

[1st episode, preadolescents >45 kg and adolescents]

Dose: 250 mg PO tid x7-10 days; Info: may extend tx if not healed after 10 days

[recurrence, preadolescents >45 kg and adolescents]

Dose: 1000 mg PO bid x1 day; Start: ASAP w/in 6h of sx onset; Alt: 500 mg PO x1, then 250 mg PO bid x2 days; 125 mg PO bid x5 days

[suppression, preadolescents >45 kg and adolescents]

Dose: 250 mg PO bid; Info: reassess tx need at 1y

Renal dosing

[1st episode]

renal impairment: consider decr. usual dose and/or frequency

HD: consider decr. usual dose and/or frequency; consider supplement if next maint. dose not due right after dialysis; PD: not defined

[recurrence]

CrCl 40-59: 500 mg bid x1 day; CrCl 20-39: 500 mg x1; CrCl <20: 250 mg x1

HD: 250 mg x1 after dialysis; no supplement; PD: not defined

[suppression]

CrCl 20-39: 125 mg bid; CrCl <20: 125 mg qd

HD: 125 mg 3x/wk after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: not defined

Hepatic dosing

mild-moderate impairment: no adjustment; severe impairment: not defined

SRC: NLM .