CEPHALOTHIN SODIUM W/ SODIUM CHLORIDE IN PLASTIC CONTAINER
Clinical safety rating: safe
No significant drug interactions Can cause hypernatremia and fluid overload.
Cephalothin is a first-generation cephalosporin that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), thereby inhibiting transpeptidase activity and disrupting peptidoglycan cross-linking. This leads to cell lysis and death, primarily in Gram-positive bacteria.
| Metabolism | Cephalothin is metabolized in the liver by deacetylation to desacetylcephalothin, which has less antimicrobial activity. The enzyme responsible is not specifically identified but involves hepatic esterases. |
| Excretion | Renal excretion (60-70% unchanged); biliary excretion (20-30%); fecal elimination (<1%) |
| Half-life | 0.5-1 hour; prolonged in renal impairment (up to 8-12 hours in anuria) |
| Protein binding | 65-80% bound to serum albumin |
| Volume of Distribution | 0.2-0.3 L/kg; primarily extracellular fluid |
| Bioavailability | Intravenous: 100%; intramuscular: approximately 50-60% |
| Onset of Action | Intravenous: immediate; intramuscular: 15-30 minutes |
| Duration of Action | 6-8 hours; dose adjustment required in renal failure |
1-2 g IV every 4-6 hours; maximum 12 g/day.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 50-80 mL/min: no adjustment; CrCl 25-50 mL/min: 1-2 g every 6-8 hours; CrCl 10-25 mL/min: 1-2 g every 8-12 hours; CrCl <10 mL/min: 1-2 g every 12-24 hours. |
| Liver impairment | No specific dose adjustment recommended; use caution in severe hepatic impairment. |
| Pediatric use | 100-150 mg/kg/day IV divided every 6 hours; maximum 12 g/day. |
| Geriatric use | No specific adjustment; consider renal function and reduce dose if CrCl <50 mL/min. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Can cause hypernatremia and fluid overload.
| FDA category | Animal |
| Breastfeeding | Cephalothin is excreted into human breast milk in low concentrations. The milk-to-plasma ratio is approximately 0.02–0.05. For a maternal dose of 1 g intravenously, the estimated infant dose is <1% of the therapeutic dose. Considered compatible with breastfeeding but monitor infant for potential gastrointestinal effects (e.g., diarrhea, candidiasis) or allergic reactions. |
| Teratogenic Risk |
■ FDA Black Box Warning
None
| Common Effects | fluid replacement |
| Serious Effects |
["Hypersensitivity to cephalothin, any cephalosporin, or other beta-lactam antibiotics","Absolute: Known anaphylactic reaction to penicillins due to cross-sensitivity"]
| Precautions | ["Hypersensitivity reactions: Cross-allergenicity with other beta-lactams, including penicillins; anaphylaxis may occur","Pseudomembranous colitis: Clostridium difficile-associated diarrhea can develop","Renal impairment: Dosage adjustment required due to renal excretion; monitor renal function","Bleeding risk: May potentiate anticoagulants; monitor prothrombin time","False-positive urine glucose test: With Clinitest or Benedict's solution, but not with glucose oxidase methods"] |
| Food/Dietary |
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| Cephalothin is a first-generation cephalosporin classified as FDA Pregnancy Category B. Animal reproduction studies have not demonstrated fetal risk, and there are no adequate and well-controlled studies in pregnant women. However, systemic absorption is expected to be low with intraperitoneal administration. First trimester: No evidence of teratogenicity, but data limited. Second/third trimesters: Generally considered safe; cross the placenta with therapeutic concentrations achieved in fetal serum and amniotic fluid. No known association with congenital malformations. |
| Fetal Monitoring | No specific monitoring required beyond standard obstetric care. Observe for signs of hypersensitivity or adverse effects. In prolonged therapy, monitor renal function and CBC with differential. Fetal monitoring not routinely indicated. |
| Fertility Effects | No known adverse effects on fertility in animal studies. Human data are lacking; cephalothin is not expected to impair fertility or reproductive performance. |
| No significant food interactions. Absorption is not affected by food. Avoid alcohol during treatment and for 72 hours after completion to prevent disulfiram-like reaction (reported with some cephalosporins, though rare with cephalothin). |
| Clinical Pearls | Cephalothin is a first-generation cephalosporin with activity against gram-positive cocci (excluding MRSA and enterococci) and some gram-negative rods. It is often used perioperatively for surgical prophylaxis. Note that cephalothin is not active against Pseudomonas aeruginosa, Bacteroides fragilis, or Enterobacter species. Cross-allergenicity with penicillins occurs in approximately 5-10% of patients. Administer before meals if GI upset occurs. Monitor renal function in elderly or those with preexisting renal impairment, as cephalothin may accumulate and cause nephrotoxicity. Pain at injection site and phlebitis are common with IV administration. |
| Patient Advice | Take this medication exactly as prescribed, even if you feel well. · Complete the full course of therapy to prevent resistance. · Report any signs of allergic reaction such as rash, itching, swelling, or difficulty breathing immediately. · Inform your healthcare provider if you have a history of penicillin allergy. · If you experience severe diarrhea, especially with blood or mucus, contact your doctor (possible C. difficile colitis). · Use effective contraception during treatment, as cephalothin may reduce efficacy of oral contraceptives. |