Comparative Pharmacology
Head-to-head clinical analysis: CYCLACILLIN versus DIFICID.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLACILLIN versus DIFICID.
CYCLACILLIN vs DIFICID
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Cyclacillin is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.
Fidaxomicin is a macrocyclic antibiotic that inhibits bacterial RNA polymerase, leading to RNA synthesis inhibition and cell death. It is bactericidal against Clostridioides difficile and has minimal systemic absorption.
250-500 mg orally every 6 hours.
200 mg (tablet) orally twice daily for 10 days.
None Documented
None Documented
0.5–1 hour in adults with normal renal function; prolonged to 10–15 hours in anuria.
Clinical Note
moderateCyclacillin + Probenecid
"The serum concentration of Probenecid can be increased when it is combined with Cyclacillin."
Clinical Note
moderateCyclacillin + Mycophenolic acid
"The serum concentration of the active metabolites of Mycophenolic acid can be reduced when Mycophenolic acid is used in combination with Cyclacillin resulting in a loss in efficacy."
Clinical Note
moderateCyclacillin + Plicamycin
"The serum concentration of Plicamycin can be decreased when it is combined with Cyclacillin."
Clinical Note
moderate11.7 hours (terminal half-life in healthy subjects); supports twice-daily dosing.
Primarily renal (90%) as unchanged drug via glomerular filtration and tubular secretion; negligible biliary/fecal elimination (<5%).
Fecal (primarily as unchanged drug, ~44% of dose); renal (~1.6% unchanged, <1% as metabolites); biliary (minor).
Category C
Category C
Antibiotic
Antibiotic
Cyclacillin + Valrubicin
"The serum concentration of Valrubicin can be decreased when it is combined with Cyclacillin."