Famciclovir

N/A

Herpes zoster (shingles), Recurrent herpes labialis, Genital herpes, Acute treatment of recurrent mucocutaneous herpes in HIV-infected patients, Acute treatment of recurrent episodes of genital herpes, Suppression of recurrent episodes of genital herpes

N/A

Hypersensitivity to famciclovir and penciclovir.

Famciclovir rapidly undergoes biotransformation to penciclovir, which has inhibitory activity against HSV types 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV). Thymidine kinase then phosphorylates penciclovir to a monophosphate form, which is then converted to penciclovir triphosphate. This inhibits HSV-2 DNA polymerase by competing with deoxyguanosine triphosphate, thus inhibiting herpes viral DNA synthesis and replication.

Reduced renal excretion resulting to increased plasma concentration w/ probenecid. Raloxifen may reduce the formation of penciclovir, the active metabolite of famciclovir.

Headache, nausea, diarrhoea, fatigue, dizziness, fever, paraesthesia, somnolence, vomiting, constipation, anorexia, abdominal pain, flatulence, dyspepsia; increased serum levels of ALT, alkaline phosphatase, total bilirubin and albumin; pruritus, pharyngitis, sinusitis, injury, generalised pain, rigors, back pain, arthralgia; increased serum phosphate, Na and K levels; abnormal leukocyte counts, purpura, angioedema.

Acute renal failure in patients with renal disease. Management: Supportive and symptomatic treatment. May be removed by haemodialysis.

Category B: Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

Renal impairment. Pregnancy and lactation.