Comparative Pharmacology
Head-to-head clinical analysis: BICILLIN L A versus UNIPEN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BICILLIN L A versus UNIPEN.
BICILLIN L-A vs UNIPEN
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.
Unipen (nafcillin) is a penicillinase-resistant penicillin that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), blocking transpeptidation and autolysin inhibition.
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.
500 mg to 2 g orally or intravenously every 4 to 6 hours; maximum 12 g/day IV for serious 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)
0.5-1 hour in normal renal function; prolonged to 7-10 hours in anuria or severe renal impairment.
Renal: 60-90% unchanged; biliary/fecal: minor (<10%)
Renal: 70-90% unchanged via tubular secretion and glomerular filtration; biliary: minor (<10%); fecal: minimal.
Category C
Category C
Penicillin Antibiotic
Penicillin Antibiotic