Treatment of chronic replicative hepatitis B virus infection with short-term continuous infusion of foscarnet.

Three patients with chronic replicative hepatitis B virus infection were treated for 7 days with a continuous intravenous infusion of foscarnet (trisodium phosphonoformate) after an initial bolus dose of 20 mg/kg body weight. Although the dose was calculated from a nomogram, approximately only half the intended plasma concentration (500 microM/l = 150 micrograms/l) was achieved. The levels of s-ALAT, HBV-DNA and DNA-polymerase changed only marginally during the treatment and 24-week follow-up period. All three patients remained HBsAg and HBeAg positive during treatment and follow-up. There were no severe side-effects. We conclude that foscarnet treatment with the dose regimen given in this study had no or only a minor antiviral effect in patients with chronic replicative HBV infection. It remains to be explored if higher doses, longer treatment periods or the use of foscarnet in combination regimen are more effective.