KEFLIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KEFLIN (KEFLIN).
Cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting transpeptidation and autolysin activation, leading to cell lysis.
| Metabolism | Not extensively metabolized; primarily excreted unchanged in urine via glomerular filtration and tubular secretion. |
| Excretion | Renal: 70-80% unchanged via glomerular filtration and tubular secretion; biliary: minimal (<5%); fecal: <1%. |
| Half-life | Terminal elimination half-life: 0.5-1 hour (normal renal function); prolonged to 2-3 hours in anuria. Clinically, dosing every 6 hours is recommended. |
| Protein binding | 65-75% bound to serum albumin. |
| Volume of Distribution | 0.2-0.3 L/kg; indicates distribution primarily into extracellular fluid. |
| Bioavailability | Intramuscular: approximately 90% absorbed; oral: not available (parenteral only). |
| Onset of Action | Intravenous: immediate (within minutes); intramuscular: 15-30 minutes. |
| Duration of Action | 2-4 hours after IV/IM administration; requires frequent dosing due to short half-life. |
| Molecular Weight | 396.44 |
| Action Class | Cephalosporins: 3 generation |
| Brand Substitutes | Cefilab 200 Tablet, Cefix 200 Tablet, Mahacef 200 Tablet, Cefi 200 Tablet, Ceftas 200 Tablet |
1-2 g IV/IM every 4-6 hours; maximum 12 g/day.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 30-50 mL/min: 1-2 g every 6 hours; CrCl 10-29 mL/min: 1-2 g every 8-12 hours; CrCl <10 mL/min: 1-2 g every 24-48 hours. |
| Liver impairment | No adjustment required for mild to moderate hepatic impairment (Child-Pugh A and B); use with caution in severe impairment (Child-Pugh C) due to potential for increased toxicity. |
| Pediatric use | Infants and children: 50-100 mg/kg/day IV/IM divided every 6 hours; neonates: 50 mg/kg/day IV/IM divided every 12 hours. |
| Geriatric use | Start at lower end of dosing range (1 g every 6 hours) and adjust based on renal function; monitor for adverse effects. |
| 1st trimester | Cephalosporins are generally considered safe in pregnancy; no known teratogenic effects in animal studies. Limited human data. |
| 2nd trimester | Safe to use; no known adverse fetal effects. |
| 3rd trimester | Safe to use; no known adverse fetal effects. |
Clinical note
Comprehensive clinical and safety monograph for KEFLIN (KEFLIN).
| Placental transfer | Cephalothin crosses the placenta and achieves therapeutic concentrations in fetal serum. |
| Breastfeeding | Cephalothin is excreted into breast milk in low concentrations, generally considered compatible with breastfeeding. Monitor infant for potential gastrointestinal disturbances or allergic reactions. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to cephalothin or any cephalosporinSevere immediate hypersensitivity reaction (e.g., anaphylaxis) to penicillins or beta-lactam antibiotics
| Precautions | Hypersensitivity reactions including anaphylaxis, Clostridioides difficile-associated diarrhea, Neurotoxicity with high doses or renal impairment, Antibiotic-associated colitis, Renal function monitoring |
| Food/Dietary | Take with food or milk to reduce gastrointestinal upset. Avoid alcohol during treatment and for 72 hours after last dose due to possible disulfiram-like reaction. No significant interactions with specific foods. |
Loading safety data…
| L2 (Probably Compatible) |
| Teratogenic Risk | FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, but no adequate human studies in pregnant women. Cephalothin crosses the placenta. First trimester: No known teratogenic effects. Second and third trimesters: Generally considered safe; use only if clearly needed. |
| Fetal Monitoring | Monitor for signs of hypersensitivity reactions in mother. No specific fetal monitoring required; standard obstetrical care. |
| Fertility Effects | No known adverse effects on fertility. Animal studies have not reported impaired fertility. |
| Clinical Pearls |
| Keflin (cephalothin) is a first-generation cephalosporin with activity against Gram-positive cocci and some Gram-negative rods. It is not active against MRSA or enterococci. For serious infections, consider higher doses and monitor renal function due to potential nephrotoxicity, especially with concurrent aminoglycosides. Use with caution in patients with penicillin allergy due to potential cross-reactivity (~5-10%). Pain at injection site is common; ensure proper intramuscular injection technique. Administer IV slowly over 3-5 minutes to avoid thrombophlebitis. |
| Patient Advice | Complete the full course of antibiotics even if you feel better. · Report any signs of allergic reaction: rash, itching, difficulty breathing. · This medication may cause diarrhea; contact your doctor if it becomes severe or bloody. · Take with food if stomach upset occurs. · Avoid alcohol while taking this medication to reduce risk of adverse effects. |