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. |
| Molecular Weight | 388.48 |
| 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 | Penicillin V is generally considered safe in the first trimester. Animal studies have not shown teratogenic effects; no controlled human studies exist. |
| 2nd trimester | Safe to use in the second trimester with fetal monitoring if indicated. |
| 3rd trimester | Safe in third trimester; however, use near term may theoretically affect fetal flora or cause neonatal diarrhea. |
Clinical note
Comprehensive clinical and safety monograph for PENTIDS '800' (PENTIDS '800').
| Placental transfer | Penicillin V crosses the placenta; fetal serum levels are approximately 10% of maternal serum levels. |
| Breastfeeding | Penicillin V is excreted into breast milk in low concentrations, unlikely to cause adverse effects in nursing infants. Potential risks include alteration of infant gut flora and allergic sensitization. Use caution in infants with known penicillin allergy. |
■ 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 |
Hypersensitivity to penicillinsHistory of severe penicillin allergy (anaphylaxis)
| 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 |
Loading safety data…
| Lactation Rating | L1 (Safe) |
| 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. |
| 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. |
| Food/Dietary | Absorption is significantly decreased by food; take at least 1 hour before meals or 2 hours after meals. Avoid acidic beverages (orange juice, tomato juice) as they may degrade the drug. No other significant food interactions. |
| Clinical Pearls | PENTIDS '800' (Penicillin V Potassium) is a narrow-spectrum penicillin primarily used for streptococcal infections. For group A streptococcal pharyngitis, treat for 10 days to prevent rheumatic fever. Administer on an empty stomach (1 hour before or 2 hours after meals) for optimal absorption. Renal dose adjustment required for CrCl <10 mL/min. First-line for pneumococcal infections but resistance is increasing. |
| Patient Advice | Take this medication exactly as prescribed, even if you feel better. · Take on an empty stomach with a full glass of water. · Complete the full course of therapy to prevent resistance. · Notify your doctor if you develop rash, itching, or difficulty breathing. · Inform your physician about all allergies, especially to penicillins or cephalosporins. · This medication may cause diarrhea; contact your doctor if severe or persistent. · Store at room temperature away from moisture and heat. · Do not share this medication with others. |