DURACILLIN A.S.
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DURACILLIN A.S. (DURACILLIN A.S.).
Penicillin G procaine is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.
| Metabolism | Primarily renal excretion as unchanged drug; minor hepatic metabolism. |
| Excretion | Primarily renal (60-90% unchanged via tubular secretion and glomerular filtration); minor biliary/fecal elimination (<10%) |
| Half-life | 0.5-1 hour in adults with normal renal function; prolonged to 7-10 hours in end-stage renal disease |
| Protein binding | 60-80% bound primarily to albumin |
| Volume of Distribution | 0.3-0.4 L/kg; limited distribution into CSF, eyes, and prostate unless inflamed |
| Bioavailability | Intramuscular: 100% (complete absorption from depot); Oral: not applicable (not orally administered) |
| Onset of Action | Intramuscular: 1-2 hours for detectable serum levels; clinical effect within 12-24 hours due to slow release from depot |
| Duration of Action | Intramuscular: 12-24 hours for procaine penicillin; single dose provides therapeutic concentrations for 24 hours, requiring daily dosing for most infections |
600,000 units intramuscularly once daily; or 1.2 million units intramuscularly every 12 hours for severe infections.
| Dosage form | INJECTABLE |
| Renal impairment | No adjustment required; drug is minimally renally excreted. |
| Liver impairment | No adjustment required; drug is not hepatically metabolized. |
| Pediatric use | Neonates: 50,000 units/kg intramuscularly once daily; Infants and children: 50,000 units/kg intramuscularly once daily (maximum 2.4 million units/day). |
| Geriatric use | No specific adjustment; use with caution due to increased risk of adverse effects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DURACILLIN A.S. (DURACILLIN A.S.).
| Breastfeeding | Penicillin G is excreted into breast milk in low concentrations (M/P ratio approximately 0.2-0.3). It is considered compatible with breastfeeding. No adverse effects on nursing infants have been reported. Caution if infant has allergy or diarrhea. |
| Teratogenic Risk | Penicillin G procaine (Duracillin A.S.) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, and there are no adequate well-controlled studies in pregnant women. However, penicillin antibiotics are generally considered safe in pregnancy. No specific teratogenic effects have been reported in first, second, or third trimester. Use only if clearly needed. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
["Hypersensitivity to penicillins or procaine","Severe renal impairment (CrCl <10 mL/min) without alternate therapy"]
| Precautions | ["Severe hypersensitivity reactions (anaphylaxis) can occur","Use caution in renal impairment (requires dose adjustment)","Risk of neurotoxicity with high doses or prolonged use","Procaine reactions (anxiety, confusion, hallucinations) may occur","Monitor for superinfection"] |
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| Fetal Monitoring | Monitor for allergic reactions, including anaphylaxis. In prolonged therapy, monitor renal and hematologic function. Fetal monitoring is not specifically required but standard obstetric care applies. |
| Fertility Effects | No known adverse effects on fertility. Animal studies have not shown impaired fertility. Clinical data insufficient to conclude any impact on human fertility. |