Comparative Pharmacology
Head-to-head clinical analysis: CYCLACILLIN versus SEPTRA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLACILLIN versus SEPTRA.
CYCLACILLIN vs SEPTRA
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.
SEPTRA (trimethoprim/sulfamethoxazole) is a combination of two antifolate agents: sulfamethoxazole inhibits dihydropteroate synthase, blocking the conversion of PABA to dihydrofolic acid; trimethoprim inhibits dihydrofolate reductase, preventing the reduction of dihydrofolic acid to tetrahydrofolic acid. This sequential blockade disrupts bacterial folate synthesis and nucleic acid production.
250-500 mg orally every 6 hours.
Trimethoprim-sulfamethoxazole (TMP-SMX) 160 mg/800 mg (double strength) orally every 12 hours; for severe infections, intravenous dosing: 8-10 mg/kg/day (TMP component) divided every 6, 8, or 12 hours.
None Documented
None Documented
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
moderate0.5–1 hour in adults with normal renal function; prolonged to 10–15 hours in anuria.
Sulfamethoxazole: 9-12 hours (normal renal function); Trimethoprim: 8-11 hours (normal renal function). In severe renal impairment (CrCl <15 mL/min), half-life prolongs significantly (up to 24-30 hours for sulfamethoxazole, 20-30 hours for trimethoprim).
Primarily renal (90%) as unchanged drug via glomerular filtration and tubular secretion; negligible biliary/fecal elimination (<5%).
Renal excretion of unchanged sulfamethoxazole (~20%) and trimethoprim (~50-60%) with additional hepatic metabolism (acetylation, glucuronidation) of sulfamethoxazole; total renal elimination accounts for ~80-90% of the dose (sulfamethoxazole 30% parent, 40% metabolites; trimethoprim 60-80% parent, remainder as metabolites). Biliary/fecal <5%.
Category C
Category C
Antibiotic
Antibiotic
Cyclacillin + Valrubicin
"The serum concentration of Valrubicin can be decreased when it is combined with Cyclacillin."