Netivudine is a potent nucleoside reverse transcriptase inhibitor (NRTIs), a nucleoside analogue with anti-varicella zoster virus activity that can be used to treat human immunodeficiency virus (HIV) infection. Netivudine works by inhibiting reverse transcriptase, which reduces viral load in the body and slows the progression of the disease through its inhibitory effect.

VZV:0.6-3.8μM

The phosphorylation of netivudine in VZV infected human cells is similar to that of sorivudine and the IC50 of netivudine for VZV ranges from 06-3.8 uM. Since, in HSV-infected cells, only the monophosphate is formed, netivudine shows no appreciable in vitro activity against HSV or other human herpesviruses.[1]

The half-life of netivudine in humans is about 12-15 hand preliminary pharmacokinetic studies, employing oral doses of netivudine at 100 mg, 200 mg and 400 mg in young adults and healthy elderly volunteers, confirmed that concentrations of the drug substantially above the IC50 for VZV could be achieved and sustained with twice daily dosing.[2] The drug bioavailability was 21.1% and 24.6% in the young and elderly, respectively. An initial, open, dose-ranging study of netivudine in 31 elderly immunocompetent patients with localised herpes zoster with oral doses up to 200mg twice daily showed therapeutic benefits upon rash healing and pain and no significant adverse effects.[3]