Comparative Pharmacology
Head-to-head clinical analysis: ACYCLOVIR versus COPEGUS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ACYCLOVIR versus COPEGUS.
ACYCLOVIR vs COPEGUS
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.
Ribavirin is a nucleoside analogue that inhibits viral RNA synthesis by interfering with RNA capping and polymerase activity, and may also modulate immune responses.
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.
800 mg orally twice daily to 1200 mg orally twice daily based on body weight (≤75 kg: 800 mg; >75 kg: 1200 mg), in combination with ribavirin, for 24 to 48 weeks depending on genotype.
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.
Terminal elimination half-life is approximately 120-170 hours following multiple doses, supporting once-daily dosing with prolonged viral suppression.
Renal excretion of unchanged drug via glomerular filtration and tubular secretion accounts for 62-90% of elimination. Fecal elimination is <2%.
Ribavirin is primarily eliminated renally as unchanged drug (61%) and metabolites (30%); biliary/fecal excretion accounts for ~9%.
Category A/B
Category C
Antiviral
Antiviral