Valtrex Dosage

 Recommended Adult Dosing

Dosage forms:  TAB: 500 mg, 1000 mg

Genital HSV, immunocompetent pts

[1st episode]

Dose: 1000 mg PO q12h x7-10 days; Start: ASAP w/in 72h of sx onset, maximum efficacy w/in 48h; Info: may extend tx if not healed after 10 days

[recurrence]

Dose: 500 mg PO q12h x3 days; Start: ASAP w/in 24h of sx onset; Alt: 1000 mg PO qd x5 days

[suppression]

Dose: 1000 mg PO qd; Info: give 500 mg PO bid in pregnant pts, start at 36 wk gestation; decr. dose to 500 mg PO qd if <10 outbreaks/y; reassess tx need at 1y

Genital HSV, immunocompromised pts

[*1st episode]

Dose: 1000 mg PO q12h x7-10 days; Start: ASAP w/in 72h of sx onset, maximum efficacy w/in 48h; Info: may extend tx if not healed after 10 days

[*recurrence]

Dose: 1000 mg PO q12h x5-10 days

[suppression]

Dose: 500 mg PO q12h; Info: reassess tx need at 1y

Herpes labialis (cold sores)

[episode]

Dose: 2000 mg PO q12h x1 day; Start: ASAP after sx onset

[*suppression]

Dose: 500 mg PO qd; Info: reassess tx need at 4mo

Herpes zoster (shingles)

[1000 mg PO q8h x7 days]

Start: ASAP w/in 72h of rash onset, maximum efficacy w/in 48h; Info: may use for herpes zoster ophthalmicus

Renal dosing

[if usual dose 500 mg qd]

CrCl <29: 500 mg q48h

HD: 500 mg q48h, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[if usual dose 500 mg q12h]

CrCl <29: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[if usual dose 1000 mg qd]

CrCl <29: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[if usual dose 1000 mg q12h]

CrCl 10-29: 1000 mg qd; CrCl <10: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[if usual dose 1000 mg q8h]

CrCl 30-49: 1000 mg q12h; CrCl 10-29: 1000 mg qd; CrCl <10: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[if usual dose 2000 mg q12h x1 day]

CrCl 30-49: 1000 mg q12h x1 day; CrCl 10-29: 500 mg q12h x1 day; CrCl <10: 500 mg x1

HD: 500 mg x1 after dialysis; no supplement; PD: 500 mg q48h; no supplement

Hepatic dosing

[no adjustment]

 Recommended Peds Dosing

Dosage forms:  TAB: 500 mg, 1000 mg

Herpes labialis (cold sores)

[12 yo and older]

Dose: 2000 mg PO q12h x1 day; Start: ASAP after sx onset

Varicella (chicken pox), immunocompetent pts

[2 yo and older]

Dose: 20 mg/kg/dose PO q8h x5 days; Start: ASAP w/in 24h of rash onset; Max: 1000 mg/dose

Genital HSV

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

Dose: 1000 mg PO q12h x10 days; Start: ASAP w/in 72h of sx onset, maximum efficacy w/in 48h; Info: may extend tx if not healed after 10 days

[recurrence, preadolescents >45 kg and adolescents]

Dose: 500 mg PO q12h x3 days; Alt: 1 g q24h x5 days; Start: ASAP w/in 24h of sx onset

[suppression, preadolescents >45 kg and adolescents]

Dose: 1000 mg PO qd; Info: give 500 mg PO bid in pregnant pts, start at 36 wk gestation; decr. dose to 500 mg PO qd if <10 outbreaks/y; reassess tx need at 1y

Renal dosing

[varicella (chicken pox)]

CrCl 30-50: give usual dose q12h; CrCl 10-29: give usual dose q24h; CrCl <10: give 50% usual dose q24h

HD: give 50% usual dose q24h, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: give 50% usual dose q24h; no supplement

[all other indications, usual dose 500 mg q12h]

CrCl <29: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[all other indications, usual dose 1000 mg qd]

CrCl <29: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[all other indications, usual dose 1000 mg q12h]

CrCl 10-29: 1000 mg qd; CrCl <10: 500 mg qd

HD: 500 mg qd, on dialysis days admin. after dialysis; consider supplement if next maint. dose not due right after dialysis; PD: 500 mg q48h; no supplement

[all other indications, usual dose 2000 mg q12h x1 day]

CrCl 30-49: 1000 mg q12h x1 day; CrCl 10-29: 500 mg q12h x1 day; CrCl <10: 500 mg x1

HD: 500 mg x1 after dialysis; no supplement; PD: 500 mg q48h; no supplement

Hepatic dosing

[no adjustment]