Comparative Pharmacology
Head-to-head clinical analysis: BICILLIN L A versus PENICILLIN VK.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BICILLIN L A versus PENICILLIN VK.
BICILLIN L-A vs PENICILLIN-VK
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Penicillin VK inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting transpeptidase activity, and activating autolytic enzymes.
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.
250-500 mg orally every 6-8 hours for mild to moderate infections; 500 mg orally every 6 hours for severe infections (e.g., streptococcal pharyngitis, skin infections).
None Documented
None Documented
Terminal half-life: 30-60 hours (prolonged due to slow absorption from IM depot; clinically allows single-dose regimen for syphilis)
0.5 hours (normal renal function); prolonged to 3-10 hours in severe renal impairment (CrCl <10 mL/min).
Renal: 60-90% unchanged; biliary/fecal: minor (<10%)
Renal: 20-40% unchanged via tubular secretion; hepatic metabolism to penicilloic acid; biliary/fecal: minimal (<5%).
Category C
Category C
Penicillin Antibiotic
Penicillin Antibiotic