Consider a more convenient option when prescribing antiviral drug for herpes zoster
Herpes zoster or shingles is a viral infection characterized by pain followed by a vesicular rash. It is caused by reactivation of the varicella zoster virus (VZV). The aim of treatment is to hasten healing, reduce the severity and duration of pain and also to reduce the chances of complications such as post-herpetic neuralgia.
Timely administration of antiviral drugs – acyclovir, valacyclovir and famciclovir – decreases viral shedding and reduces the acute pain in patients with uncomplicated infection. These clinical benefits have been demonstrated in various clinical trials.
Acyclovir has to be administered five times daily, which may hinder patient compliance to prescribed treatment. This is especially of concern in the elderly, in whom herpes zoster is most prevalent.
The prodrug of acyclovir, valacyclovir, is administered thrice daily as treatment for herpes zoster and the serum levels achieved are 3 to 5 times higher than those obtained with oral acyclovir.
Famciclovir is a prodrug of penciclovir and is also administered thrice daily as treatment for herpes zoster.
Therefore, when compliance is a concern or convenience of dosing is required, valacyclovir and famciclovir are useful and convenient alternatives to acyclovir as treatment for herpes zoster.