Comparative Pharmacology
Head-to-head clinical analysis: ACYCLOVIR versus HARVONI.
Head-to-head clinical analysis: ACYCLOVIR versus HARVONI.
ACYCLOVIR vs HARVONI
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Acyclovir is a synthetic nucleoside analog that inhibits viral DNA replication. It is phosphorylated to acyclovir monophosphate by viral thymidine kinase, then converted to acyclovir triphosphate by cellular kinases. Acyclovir triphosphate competes with deoxyguanosine triphosphate for viral DNA polymerase, incorporating into viral DNA and causing chain termination.
Fixed-dose combination of ledipasvir, an HCV NS5A inhibitor, and sofosbuvir, an HCV NS5B nucleotide polymerase inhibitor. Ledipasvir inhibits HCV NS5A protein essential for viral replication and assembly; sofosbuvir is a prodrug that after intracellular metabolism acts as a chain terminator by inhibiting NS5B RNA-dependent RNA polymerase.
400 mg orally twice daily for herpes zoster; 200 mg orally 5 times daily for genital herpes; 5-10 mg/kg intravenously every 8 hours for severe infections.
One tablet (90 mg ledipasvir/400 mg sofosbuvir) orally once daily with or without food for 12 weeks. For treatment-naïve patients with genotype 1 and cirrhosis, 24 weeks may be considered. For genotype 4, 12 weeks recommended.
None Documented
None Documented
Clinical Note
moderateAcyclovir + Teriflunomide
"The serum concentration of Teriflunomide can be increased when it is combined with Acyclovir."
Clinical Note
moderateTizanidine + Acyclovir
"The serum concentration of Acyclovir can be increased when it is combined with Tizanidine."
Terminal elimination half-life is 2.5–3.3 hours in adults with normal renal function; increases to 19.5 hours in anuria.
Ledipasvir: 47 hours; Sofosbuvir: 0.5 hours; GS-331007 (predominant circulating metabolite): 27 hours; clinical context: supports once-daily dosing with no accumulation beyond steady state by day 7
Renal excretion of unchanged drug via glomerular filtration and tubular secretion accounts for 62-90% of elimination. Fecal elimination is <2%.
Ledipasvir: 86% fecal, 1% renal; Sofosbuvir: 80% renal (as inactive metabolite GS-331007), 14% fecal; GS-331007: 78% renal
Category A/B
Category C
Antiviral
Antiviral