Famciclovir

Administration

  • Type: Antiviral
  • Dosage Forms:
  • Routes of Administration: Oral
  • Common Trade Names: Famvir

Adult Dosing

  • 150-1000mg PO BID

Herpes zoster oticus

  • 500mg TID x 7 days

HSV-1

  • 500mg PO TID

Pediatric Dosing

Safety/efficacy not established

Special Populations

  • Pregnancy Rating: B
  • Lactation risk: Infant risk cannot be ruled out
  • Renal dosing: reduced dose
  • Hepatic dosing: no adjustment for mild-moderate impairment
  • Famvir Pregnancy Registry: 1-888-669-6682

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

  • Neutropenia, thrombocytopenia
  • Skin reaction, severe
  • Hallucinations, delirium

Common

  • Nausea/vomiting, diarrhea
  • Headache
  • Fatigue
  • Elevated AST/ALT
  • Pruritus
  • Paresthesia
  • Flatulence

Pharmacology

  • Half-life: 2.3h
  • Metabolism: Hepatic, CYP450
  • Excretion: Mostly renal

Mechanism of Action

  • Inhibits DNA polymerase, selectively inhibiting herpes viral DNA synthesis and replication

Comments

See Also

References