Comparative Pharmacology
Head-to-head clinical analysis: TYZEKA versus VALACYCLOVIR HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TYZEKA versus VALACYCLOVIR HYDROCHLORIDE.
TYZEKA vs VALACYCLOVIR HYDROCHLORIDE
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).
Valacyclovir hydrochloride is a prodrug of acyclovir. After oral administration, it is rapidly converted to acyclovir, which inhibits viral DNA polymerase, leading to chain termination and inhibition of viral DNA replication.
600 mg orally once daily
500 mg orally twice daily for recurrent genital herpes; 1 g orally twice daily for herpes zoster; 1 g orally three times daily for herpes simplex encephalitis or immunocompromised patients.
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: 2.5–3.3 hours in patients with normal renal function; prolonged to 14 hours in renal impairment (CrCl 15–30 mL/min).
Renal excretion of unchanged drug accounts for approximately 40% of the administered dose; biliary/fecal excretion accounts for approximately 60%.
Renal excretion: >90% as unchanged drug and inactive metabolite (9-carboxymethoxymethylguanine). Biliary/fecal: <2%.
Category C
Category A/B
Antiviral, Hepatitis B
Antiviral