Comparative Pharmacology
Head-to-head clinical analysis: SYMMETREL versus TYZEKA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SYMMETREL versus TYZEKA.
SYMMETREL vs TYZEKA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Inhibits influenza A virus uncoating and viral RNA replication; increases dopamine release and blocks dopamine reuptake in the CNS.
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).
100 mg orally twice daily; may increase to 200 mg orally twice daily if tolerated, usually in divided doses. For Parkinson's disease, 100 mg orally twice daily; for drug-induced extrapyramidal reactions, 100 mg orally twice daily.
600 mg orally once daily
None Documented
None Documented
Terminal half-life: 24-48 hours (young adults); 48-72 hours (elderly); may extend to 7-10 days in severe renal impairment. Clinically, steady-state achieved in 4-7 days.
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.
Primarily renal excretion (90-95% unchanged) via glomerular filtration and tubular secretion; minor fecal (<5%). Dose adjustment required in renal impairment.
Renal excretion of unchanged drug accounts for approximately 40% of the administered dose; biliary/fecal excretion accounts for approximately 60%.
Category C
Category C
Antiviral and Antiparkinsonian
Antiviral, Hepatitis B