Entecavir

Comparative studies

In a comparison of entecavir and lamivudine, diminution of viral titers reached 7 log ₁₀ units [ ]. There were no significant differences in adverse events compared with lamivudine. Most of the adverse events were mild or moderate and the incidences were comparable in the four treatment groups, 65–73% of patients describing at least one adverse event. One patient taking entecavir had asymptomatic increases in alanine transaminase activity and bilirubin concentration; the drug was withdrawn and the tests improved. Two patients withdrew from the study, one because of lethargy and photosensitivity after 5 months, which resolved 3 days after withdrawal, and the other because of acute HIV infection.

In other studies, oral entecavir 0.5 mg/day produced greater improvement in biochemical, histological, and virological outcomes than lamivudine 100 mg/day in HBeAg-positive and HBeAg-negative patients. Common adverse effects included headache, upper respiratory tract infections, nasopharyngitis, cough, pyrexia, dyspepsia, upper abdominal pain, fatigue, diarrhea, back pain, and myalgia; most were of mild-to-moderate intensity. More patients had rises in alanine transaminase activity and there were more withdrawals due to adverse reactions in those who took lamivudine [ ].