Comparative Pharmacology
Head-to-head clinical analysis: BICILLIN C R versus BICILLIN L A.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BICILLIN C R versus BICILLIN L A.
BICILLIN C-R vs BICILLIN L-A
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Benzathine penicillin G and procaine penicillin G are beta-lactam antibiotics that inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting transpeptidase activity, and activating autolytic enzymes, leading to cell lysis.
Penicillin G benzathine is a slow-release formulation that provides prolonged tissue concentrations. It inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting transpeptidation, and activating autolytic enzymes, leading to cell lysis.
1.2 million units intramuscularly as a single dose (600,000 units procaine penicillin G and 600,000 units benzathine penicillin G) for moderate to severe infections; for mild infections, 600,000 units intramuscularly as a single dose.
1.2 million units intramuscularly as a single dose for treatment of streptococcal pharyngitis; for syphilis, 2.4 million units intramuscularly weekly for 1-3 weeks depending on stage.
None Documented
None Documented
Penicillin G: 0.5-1 hour in normal renal function; prolonged to 7-10 hours in anuria. Benzathine component sustains low levels for days; effective half-life of benzathine penicillin G is 3-5 days due to slow release.
Terminal half-life: 30-60 hours (prolonged due to slow absorption from IM depot; clinically allows single-dose regimen for syphilis)
Renal excretion primarily via glomerular filtration and tubular secretion; approximately 60-70% of penicillin G is excreted unchanged in urine within 6 hours; benzathine and procaine components are metabolized and excreted renally as well; small amounts in bile and feces.
Renal: 60-90% unchanged; biliary/fecal: minor (<10%)
Category C
Category C
Penicillin Antibiotic
Penicillin Antibiotic