Brivudin is an oral
thymidine analogue indicated for the early treatment of acute
herpes zoster in immunocompetent adults. It has high, selective activity against varicella zoster virus (VZV), inhibiting VZV replication, possibly through competitive inhibition of
viral DNA polymerase, or by acting as an alternative substrate to
deoxythymidine triphosphate, causing
viral DNA strand breakage. In a large, 7-day, phase III trial in immunocompetent patients with
herpes zoster, once-daily
brivudin 125mg was significantly more effective than oral
acyclovir 800mg five times daily in reducing the mean time from start of treatment to last vesicular eruption, and was as effective as
acyclovir at healing lesions and alleviating acute
zoster-related
pain. The likelihood of developing post-herpetic
neuralgia (PHN) in immunocompetent patients aged > or =50 years was significantly lower with
brivudin than with
acyclovir.
Brivudin was as effective as oral
famciclovir 250mg three times daily in terms of the prevalence of PHN, the time to last vesicular eruption and lesion healing in another large, 7-day, phase III study in immunocompetent patients with
herpes zoster. Oral
brivudin is generally well tolerated, with a similar tolerability profile to those of oral
acyclovir or
famciclovir.
Nausea was the most commonly reported adverse event.