PENTIDS '800'
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PENTIDS '800' (PENTIDS '800').
Penicillin G is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), transpeptidases that catalyze the final transpeptidation step of peptidoglycan cross-linking, leading to cell lysis.
| Metabolism | Penicillin G is primarily metabolized in the liver via hydrolysis to penicilloic acid (inactive), with minor contributions from other pathways. Approximately 60-90% of an intravenous dose is excreted unchanged in the urine by tubular secretion; elimination half-life is 0.5-1 hour (prolonged in renal impairment). |
| Excretion | Renal: ~60-85% unchanged via glomerular filtration and tubular secretion; Biliary: ~10%; Fecal: <5%. |
| Half-life | 0.5-1 hour; prolonged to 2-5 hours in renal impairment. |
| Protein binding | ~80% bound to serum albumin. |
| Volume of Distribution | 0.3-0.4 L/kg; low distribution, primarily extracellular fluid. |
| Bioavailability | Oral: 60-70% (reduced by food); IM: ~100%. |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes; IV: immediate. |
| Duration of Action | Oral: 4-6 hours; IM: 4-6 hours; IV: 2-4 hours; dose-dependent. |
| Action Class | Cell wall active agent - Narrow spectrum Penicillin |
| Brand Substitutes | Pentas 800 Tablet, Pencip 800000IU Tablet |
800 mg orally every 6 to 8 hours; maximum 4 g per day.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-50 mL/min: 800 mg every 8-12 hours; CrCl 10-29 mL/min: 800 mg every 12-24 hours; CrCl <10 mL/min: 800 mg every 24 hours. |
| Liver impairment | No specific adjustment required in mild to moderate hepatic impairment; contraindicated in severe hepatic impairment (Child-Pugh Class C). Caution in Child-Pugh Class B. |
| Pediatric use | Children 2-12 years: 25-50 mg/kg/day divided every 6-8 hours; maximum 2 g per day. Infants and neonates: based on gestational and postnatal age, consult specific guidelines. |
| Geriatric use | Use lowest effective dose; monitor renal function; increased risk of QT prolongation and Clostridioides difficile infection. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PENTIDS '800' (PENTIDS '800').
| Breastfeeding | Penicillin G is excreted into breast milk in low concentrations (M/P ratio approximately 0.2). The amount ingested is unlikely to cause adverse effects in the nursing infant. However, there is potential for alteration of infant gut flora and allergic sensitization. Use with caution in breastfeeding women, especially in infants with history of penicillin allergy. |
| Teratogenic Risk | Pentids '800' contains penicillin G. Penicillin G is considered low risk in pregnancy. No increased risk of major congenital malformations has been observed with first trimester exposure. Second and third trimester use is safe when indicated. However, high doses near term may increase risk of neonatal hyperbilirubinemia and kernicterus due to competition for bilirubin binding sites. |
■ FDA Black Box Warning
WARNING: SERIOUS HYPERSENSITIVITY REACTIONS, INCLUDING ANAPHYLAXIS, HAVE BEEN REPORTED IN PATIENTS ON PENICILLIN THERAPY. THESE REACTIONS ARE MORE LIKELY TO OCCUR IN INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY AND/OR A HISTORY OF SENSITIVITY TO MULTIPLE ALLERGENS. THERE HAVE BEEN REPORTS OF INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY WHO HAVE EXPERIENCED SEVERE HYPERSENSITIVITY REACTIONS WHEN TREATED WITH CEPHALOSPORINS. BEFORE INITIATING THERAPY WITH PENICILLIN, CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, OR OTHER ALLERGENS. IF AN ALLERGIC REACTION OCCURS, PENICILLIN SHOULD BE DISCONTINUED AND APPROPRIATE THERAPY INSTITUTED. SERIOUS ANAPHYLACTIC REACTIONS REQUIRE IMMEDIATE EMERGENCY TREATMENT WITH EPINEPHRINE. OXYGEN, INTRAVENOUS STEROIDS, AND AIRWAY MANAGEMENT, INCLUDING INTUBATION, SHOULD ALSO BE ADMINISTERED AS INDICATED.
| Serious Effects |
["History of hypersensitivity to any penicillin","History of immediate-type hypersensitivity reaction (e.g., anaphylaxis, urticaria) to cephalosporins or other beta-lactam antibiotics"]
| Precautions | ["Hypersensitivity reactions ranging from rash to anaphylaxis","Serious and occasionally fatal hypersensitivity reactions (including anaphylaxis) have been reported","Cross-sensitivity with cephalosporins and other beta-lactams","Clostridium difficile-associated diarrhea (CDAD) and pseudomembranous colitis","Overgrowth of non-susceptible organisms (including fungi) with prolonged use","Jarisch-Herxheimer reaction when treating syphilis or other spirochetal infections","Electrolyte disturbances with high doses (sodium content per million units: approximately 2.0 mEq)","Neurotoxicity (including seizures) with high doses or in patients with renal impairment","Hematologic adverse reactions (including positive Coombs test, hemolytic anemia, leukopenia, thrombocytopenia) with prolonged therapy","Interstitial nephritis","Use in patients with asthma or history of allergies requires caution"] |
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| Fetal Monitoring | Monitor for signs of maternal hypersensitivity reactions. In pregnancy, assess for preterm labor or chorioamnionitis if treated for intra-amniotic infection. Fetal monitoring may include non-stress test or biophysical profile if concern for fetal distress. In newborn, observe for rash, diarrhea, or candidiasis. No specific routine monitoring required beyond standard obstetric care. |
| Fertility Effects | No known adverse effects on fertility. Penicillin G does not impair spermatogenesis or oogenesis. No evidence of reduced fertility in animal studies or human data. |