Current licensed and off-labeled antivirals for HZ
| Classification | Antivirals | Dosing schedule | Characteristics |
|---|---|---|---|
| Nucleoside analogs | |||
| Acyclovir | 5 × 800 mg/day P.O. | Limited bioavailability | |
| FDA approval for HZ | |||
| Nephropathy | |||
| Usually for 5–7 days | |||
| 3 × 500 mg/day I.V. followed by oral regimens for 10–14 days | |||
| Valacyclovir | 3 × 1,000 mg/day P.O. | Prodrug of acyclovir with 54% bioavailability | |
| FDA approval for HZ | |||
| For 7 days | |||
| Famciclovir | 3 × 250–500 mg/day P.O. | Prodrug of penciclovir with 77% bioavailability | |
| FDA approval for HZ | |||
| For 7 days | |||
| Brivudine | 1 × 125 mg/day P.O. | Some Europe approval for HZ | |
| No renal toxicity | |||
| For 5 days | |||
| Pyrophosphate analogs | |||
| Foscarnet | I.V. only | FDA non-approval for HZ | |
| Off-label acyclovir resistance | |||
| Nephrotoxicity, electrolyte imbalance, genital ulcer | |||
| Nucleotide analogs | |||
| Cidofovir | I.V. only | FDA non-approval for HZ | |
| Off-label acyclovir or foscarnet resistance | |||
| Nephrotoxicity, neutropenia | |||
| Helicase-primase inhibitor | |||
| Amenamevir | 1 × 400 mg/day P.O. | Japan approval for HZ | |
| For 7 days | |||
HZ: herpes zoster, P.O.: per oral, I.V.: intravenous, FDA: Food and Drug Administration.