MEFOXIN IN DEXTROSE 5% IN PLASTIC CONTAINER
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MEFOXIN IN DEXTROSE 5% IN PLASTIC CONTAINER (MEFOXIN IN DEXTROSE 5% IN PLASTIC CONTAINER).
Cefoxitin is a cephamycin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death. It is active against a broad spectrum of gram-positive and gram-negative aerobic and anaerobic bacteria.
| Metabolism | Cefoxitin is not significantly metabolized; it is primarily excreted unchanged by the kidneys via glomerular filtration and tubular secretion. |
| Excretion | Renal: 85% unchanged via glomerular filtration and tubular secretion. Biliary: <1%. Fecal: <1%. |
| Half-life | Terminal elimination half-life: 0.7-1.1 hours (normal renal function). In anuria: 13-23 hours. Clinical context: Dosing interval adjustment required for CrCl <50 mL/min. |
| Protein binding | ~73% bound to serum albumin. |
| Volume of Distribution | 0.13-0.27 L/kg (approximates extracellular fluid volume). Clinical meaning: Low distribution, primarily in extracellular space. |
| Bioavailability | IV: 100% (bioavailability not applicable). No oral formulation. |
| Onset of Action | IV: Immediate; peak serum concentrations achieved by end of infusion. IM: Not applicable (IV use only). |
| Duration of Action | 4-8 hours (bactericidal levels maintained). Clinical note: Prolonged in renal impairment. |
| Molecular Weight | 427.45 |
1-2 g IV every 6-8 hours (Cefoxitin).
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 30-50 mL/min: 1-2 g IV every 8-12 hours; CrCl 10-29 mL/min: 1-2 g IV every 12-24 hours; CrCl <10 mL/min: 1-2 g IV every 24-48 hours. |
| Liver impairment | No dose adjustment required for Child-Pugh A or B. For Child-Pugh C, use with caution and monitor; no specific dosing guidelines. |
| Pediatric use | Neonates: 20-40 mg/kg/dose IV every 12 hours; Infants and children: 20-40 mg/kg/dose IV every 6-8 hours. Maximum 12 g/day. |
| Geriatric use | Adjust dose based on renal function; may require lower doses or extended intervals due to age-related decline in CrCl. |
| 1st trimester | Cefoxitin crosses the placenta. Human data are limited; however, cephalosporins are generally considered low risk in pregnancy. Use only if clearly needed. |
| 2nd trimester | No known teratogenic risk. Considered safe when indicated. Dose adjustment may be needed due to increased renal clearance. |
| 3rd trimester | Use if benefit outweighs risk. May cause alterations in neonatal gut flora; theoretical risk of diarrhea or infection. |
Clinical note
Comprehensive clinical and safety monograph for MEFOXIN IN DEXTROSE 5% IN PLASTIC CONTAINER (MEFOXIN IN DEXTROSE 5% IN PLASTIC CONTAINER).
| Placental transfer | Cefoxitin crosses the placenta. Detectable levels in cord blood after maternal administration, achieving approximately 30-100% of maternal serum levels. Animal studies show no teratogenicity. |
| Breastfeeding | Cefoxitin is excreted into human milk in small amounts. Concentrations are low (typically <1% of maternal dose). It is unlikely to cause adverse effects in the breastfed infant, but may theoretically alter infant gut microbiota or cause diarrhea. Use with caution in infants with known hypersensitivity or caution if the infant is being treated for an infection with a similar antibiotic. American Academy of Pediatrics considers cephalosporins compatible with breastfeeding. |
■ FDA Black Box Warning
No black box warning.
| Serious Effects |
Hypersensitivity to cefoxitin or other cephalosporinsHistory of severe immediate hypersensitivity reaction (e.g., anaphylaxis) to penicillins or other beta-lactams
| Precautions | Hypersensitivity reactions including anaphylaxis, Clostridium difficile-associated diarrhea, Renal impairment: dose adjustment required, Prolonged use may result in superinfection, Coagulation abnormalities, Seizures (especially with high doses in renal impairment) |
| Food/Dietary | No significant food interactions. However, alcohol should be avoided during and for 48 hours after treatment due to possible disulfiram-like reaction (cefoxitin may cause this). |
Loading safety data…
| Lactation Rating | L2 (Safe, probably compatible) |
| Teratogenic Risk | Cefoxitin is a beta-lactam antibiotic classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, but no adequate and well-controlled studies in pregnant women exist. First trimester: No evidence of teratogenicity; use only if clearly needed. Second and third trimesters: Considered safe; crosses placenta but no known adverse fetal effects. |
| Fetal Monitoring | Monitor maternal renal function and CBC with differential during prolonged therapy. In neonates exposed in utero, monitor for signs of infection (e.g., hypothermia, poor feeding). No specific fetal monitoring required beyond routine obstetrical care. |
| Fertility Effects | No known adverse effects on fertility or reproductive performance in animal studies. Human data lacking; not expected to impair fertility. |
| Clinical Pearls |
| Mefoxin (cefoxitin) in D5W is a cephamycin antibiotic. For surgical prophylaxis, infusion should be completed within 1 hour before incision; redose if procedure >2 hours or major blood loss. Contraindicated in penicillin allergy (cross-reactivity ~10%). Monitor renal function: dose adjustment needed for CrCl <50 mL/min. Do not mix with aminoglycosides in same IV line. Note that D5W may cause hyperglycemia in diabetic patients; consider NS if glucose control is a concern. |
| Patient Advice | This medication is given through a vein; you may experience pain or redness at the injection site. · Report any signs of allergic reaction: rash, itching, difficulty breathing, or swelling of face/tongue. · Complete the full course of therapy as prescribed, even if you feel better. · Inform your doctor if you have kidney disease, diabetes, or a history of penicillin allergy. · Increase fluid intake to prevent kidney issues unless fluid restriction is advised. · Diarrhea, nausea, or headache may occur; contact your doctor if diarrhea becomes severe or bloody. |