Comparative Pharmacology
Head-to-head clinical analysis: TYZEKA versus ZIRGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TYZEKA versus ZIRGAN.
TYZEKA vs ZIRGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Telbivudine is a synthetic thymidine nucleoside analogue with activity against hepatitis B virus (HBV). It is phosphorylated intracellularly to the active triphosphate form, which competes with natural thymidine triphosphate for incorporation into viral DNA, causing chain termination and inhibition of HBV DNA polymerase (reverse transcriptase).
Ganciclovir is a synthetic guanine derivative that inhibits cytomegalovirus (CMV) replication by competitively inhibiting viral DNA polymerase (UL54) and by incorporating into viral DNA, causing chain termination. Ganciclovir is phosphorylated to ganciclovir triphosphate by viral thymidine kinase (UL97) in CMV-infected cells.
600 mg orally once daily
Instill 1 drop (approximately 0.05 mL) into affected eye(s) 5 times daily (approximately every 3 hours while awake) until corneal ulcer heals, then reduce to 1 drop 3 times daily for 7 days.
None Documented
None Documented
Terminal elimination half-life is approximately 15 hours (range 12-20 hours) in patients with normal renal function; half-life is prolonged in renal impairment, requiring dose adjustment.
Terminal elimination half-life in patients with normal renal function is approximately 3-4 hours; in renal impairment, half-life may be prolonged up to 30 hours, requiring dose adjustment.
Renal excretion of unchanged drug accounts for approximately 40% of the administered dose; biliary/fecal excretion accounts for approximately 60%.
Primarily renal excretion as unchanged drug via glomerular filtration and tubular secretion; >90% of a systemically absorbed dose is recovered unchanged in urine.
Category C
Category C
Antiviral, Hepatitis B
Antiviral