LEDERCILLIN VK
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LEDERCILLIN VK (LEDERCILLIN VK).
Penicillin V is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death. It is bactericidal against susceptible organisms during the active growth phase.
| Metabolism | Penicillin V is primarily metabolized in the liver to penicilloic acid, which is inactive. Approximately 20-40% of the dose is metabolized; the remainder is excreted unchanged in urine. |
| Excretion | Renal elimination predominantly via tubular secretion of unchanged drug (>90% of absorbed dose). Approximately 20-40% of an oral dose is recovered in urine as unchanged penicillin V. Biliary excretion accounts for <1% of elimination; fecal elimination is negligible. |
| Half-life | Terminal elimination half-life is 0.5 hours (range 0.4–0.6 hours) in adults with normal renal function. In severe renal impairment (CrCl <10 mL/min), half-life extends to ~4 hours. |
| Protein binding | Approximately 60–80% bound to serum albumin. |
| Volume of Distribution | Volume of distribution is approximately 0.17–0.3 L/kg; low Vd reflects limited tissue penetration, consistent with a hydrophilic drug that remains primarily in extracellular fluid. |
| Bioavailability | Oral bioavailability is 60–73% under fasting conditions; food decreases absorption by 25–50%, reducing peak concentrations by up to 50%. |
| Onset of Action | Oral: Peak serum concentrations occur at 0.5–1 hour after administration (fasting). Onset of antibacterial effect is rapid, typically within 1–2 hours for susceptible organisms. |
| Duration of Action | Duration of therapeutic concentrations is approximately 4–6 hours after a single oral dose. For treatment of streptococcal pharyngitis, 10-day regimen is standard to ensure eradication. |
250-500 mg orally every 6 hours for mild to moderate infections; 500 mg orally every 6 hours for severe infections.
| Dosage form | FOR SOLUTION |
| Renal impairment | GFR 10-50 mL/min: administer every 8-12 hours; GFR <10 mL/min: administer every 12-18 hours. |
| Liver impairment | No adjustment required for mild to moderate hepatic impairment; use with caution in severe hepatic impairment (Child-Pugh class C) due to potential for accumulation, but no specific guidelines exist. |
| Pediatric use | Children >12 years: 250-500 mg orally every 6 hours; Children <12 years: 25-50 mg/kg/day orally in divided doses every 6 hours; maximum 3 g/day. |
| Geriatric use | Dose adjustment based on renal function; monitor for superinfection and adverse effects; consider age-related decline in renal function; no specific dose reduction if renal function normal. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LEDERCILLIN VK (LEDERCILLIN VK).
| Breastfeeding | Penicillin VK is excreted into breast milk in low concentrations (M/P ratio approximately 0.1-0.2). It is considered compatible with breastfeeding by the American Academy of Pediatrics. Risk of sensitization or alteration of infant gut flora is low but possible. Use with caution in infants with penicillin allergy history. |
| Teratogenic Risk | Penicillin VK (phenoxymethylpenicillin) is classified as FDA pregnancy category B. Animal reproduction studies have not demonstrated fetal risk, and there are no adequate well-controlled studies in pregnant women. However, penicillins are generally considered safe during pregnancy. No known teratogenic effects have been reported in first trimester; third trimester use associated with altered gut flora but no direct fetal harm. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
["Known hypersensitivity to penicillins or any component of the formulation.","Previous severe anaphylactic reaction to beta-lactam antibiotics (e.g., cephalosporins).","Infections caused by beta-lactamase-producing organisms (not effective)."]
| Precautions | ["Serious and occasionally fatal hypersensitivity reactions (anaphylaxis) have occurred, more frequently in patients with penicillin allergy history.","Patients with a history of severe hypersensitivity to cephalosporins or other beta-lactams should be monitored.","Use with caution in patients with renal impairment; dose adjustment may be necessary.","Prolonged use may result in overgrowth of non-susceptible organisms (e.g., Clostridioides difficile-associated diarrhea).","Hematologic reactions, including leukopenia and thrombocytopenia, have been reported with prolonged therapy."] |
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| Fetal Monitoring | No specific routine monitoring required beyond standard prenatal care. Monitor for signs of allergic reaction (rash, urticaria) and gastrointestinal symptoms. In prolonged therapy, monitor renal and hepatic function. No fetal monitoring indicated for short-term use. |
| Fertility Effects | There are no known adverse effects on fertility in either males or females based on available data. Penicillins do not interfere with spermatogenesis or ovulation. |