The researchers evaluated the antiviral effects of orally administered adefovir dipivoxil (ADV) or tenofovir disoproxil fumarate (TDF) alone, or in combination with lamivudine (3TC) or emtricitabine (FTC) in woodchucks with chronic hepatitis virus infection.
They found that once daily treatment for 48 weeks with ADV plus 3TC or TDF plus FTC greatly reduced viral levels from those pre-treatment.
It was further observed that an additional treatment with TDF plus 3TC, ADV alone, ADV plus FTC, TDF alone, 3TC alone, and FTC alone showed pronounced declines in viral levels in all groups.
While most woodchucks displayed renewed hepatitis virus replication following drug withdrawal, some did experience sustained effects.
The team, including researchers from Cornell University and Georgetown Universtiy Medical Center, did not find any toxicity following administration of any of the drugs or drug combinations.
"In conclusion, the oral administration of 3TC, FTC, ADV, and TDF alone and in combination was safe and effective in the woodchuck model of HBV infection," said the researchers.
An article describing the study has been published in the journal Antimicrobial Agents and Chemotherapy.