SEFFIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for SEFFIN (SEFFIN).
SEFFIN is a brand name for cefazolin, a first-generation cephalosporin antibiotic. It inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death. It is bactericidal against susceptible organisms.
| Metabolism | Cefazolin undergoes minimal hepatic metabolism; it is primarily excreted unchanged in the urine via glomerular filtration and tubular secretion. It is not metabolized by cytochrome P450 enzymes. |
| Excretion | Primarily renal (80-90% unchanged) via glomerular filtration and tubular secretion; minor biliary excretion (<5%) and fecal elimination. |
| Half-life | Terminal elimination half-life is approximately 0.5-1 hour in adults with normal renal function; prolonged to 20-40 hours in severe renal impairment (CrCl <10 mL/min). |
| Protein binding | Approximately 10% bound to serum proteins (mainly albumin). |
| Volume of Distribution | 0.13-0.2 L/kg, indicating limited distribution primarily to extracellular fluid. |
| Bioavailability | Intravenous: 100%; intramuscular: 100%; oral: negligible (<1%) due to instability in gastric acid. |
| Onset of Action | Intravenous: immediate; intramuscular: within 1-2 hours; oral: not applicable due to poor oral bioavailability. |
| Duration of Action | 6-8 hours for most indications; dosing interval typically 4-6 hours due to short half-life. |
| Molecular Weight | 446.37 Da |
1-2 g IV/IM every 6-8 hours; maximum 8 g/day.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 30-50 mL/min: 1-2 g every 8 hours; CrCl 10-29 mL/min: 1-2 g every 12 hours; CrCl <10 mL/min: 1-2 g every 24 hours. Hemodialysis: dose after dialysis. |
| Liver impairment | No dose adjustment required for mild-moderate impairment; severe impairment (Child-Pugh C): consider dose reduction or interval prolongation, monitor closely. |
| Pediatric use | Infants and children: 50-100 mg/kg/day IV/IM divided every 6-8 hours; neonates: 25-50 mg/kg/day every 8-12 hours. Do not exceed adult dose. |
| Geriatric use | Adjust dose based on renal function; use lower end of dosing range (e.g., 1 g every 8-12 hours). Monitor for neurotoxicity (seizures). |
| 1st trimester | Cefuroxime (SEFFIN) is generally considered safe during the first trimester as animal studies have not shown teratogenic effects. However, use only if clearly needed. |
| 2nd trimester | Safe to use during the second trimester. No known risk of harm to the fetus. |
| 3rd trimester | Safe to use during the third trimester. No known risk of harm to the fetus. |
Clinical note
Comprehensive clinical and safety monograph for SEFFIN (SEFFIN).
| Placental transfer | Cefuroxime crosses the placenta, achieving therapeutic concentrations in fetal serum and amniotic fluid. |
| Breastfeeding | Cefuroxime is excreted into breast milk in small amounts. It is generally considered compatible with breastfeeding, but monitor the infant for potential side effects such as diarrhea, thrush, or allergic reaction. |
■ FDA Black Box Warning
No FDA black box warning has been issued for cefazolin. However, note that cephalosporins are contraindicated in patients with immediate-type hypersensitivity reactions to penicillins; use with caution due to potential cross-allergenicity.
| Serious Effects |
Hypersensitivity to cefuroxime or any cephalosporinHypersensitivity to penicillins (potential cross-reactivity)
| Precautions | Hypersensitivity reactions (including anaphylaxis), Clostridium difficile-associated diarrhea, dose adjustment in renal impairment, superinfection, increased risk of bleeding with high doses, prolonged use may cause bacterial overgrowth. |
| Food/Dietary | Take with food or milk to increase absorption and reduce gastrointestinal discomfort. Avoid alcohol during therapy and for 72 hours after completion to prevent disulfiram-like reaction (reported with some cephalosporins, though rare with cefuroxime). |
Loading safety data…
| Lactation Rating |
| L2 (Probably Compatible) |
| Teratogenic Risk | SEFFIN (cefalexin, a first-generation cephalosporin) is classified as FDA Pregnancy Category B. There is no evidence of teratogenicity in animal studies. In humans, data do not indicate an increased risk of major congenital malformations. Use in the first trimester is generally considered safe; however, it should be used only when clearly needed. In the second and third trimesters, no known fetal risks have been reported. |
| Fetal Monitoring | Monitor maternal renal function and signs of hypersensitivity. In neonates, monitor for diarrhea, rash, and candidiasis. No specific fetal monitoring required. |
| Fertility Effects | No known effects on fertility. Cefalexin has not been associated with impaired fertility in animal studies or human reports. |
| Clinical Pearls | SEFFIN (cefuroxime axetil) is a second-generation cephalosporin with good activity against respiratory pathogens. Administer with food to enhance absorption. For acute otitis media, use a higher dose (250 mg BID for children, 500 mg BID for adults). Monitor renal function in elderly or renally impaired patients; adjust dose if CrCl <30 mL/min. Avoid in patients with penicillin hypersensitivity (cross-reactivity ~10%). |
| Patient Advice | Take this medication exactly as prescribed, even if you feel better. · Take with food or milk to improve absorption and reduce stomach upset. · Complete the full course of therapy to prevent resistance. · Common side effects include diarrhea, nausea, and skin rash; contact your doctor if severe or persistent. · Do not use if you have a history of severe allergic reaction to penicillins or cephalosporins. |