CEFZIL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CEFZIL (CEFZIL).
Cefprozil inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting peptidoglycan cross-linking.
| Metabolism | Cefprozil is not extensively metabolized; approximately 60% of the dose is excreted unchanged in the urine. Renal excretion via tubular secretion and glomerular filtration. |
| Excretion | Renal: 80-91% unchanged in urine; biliary/fecal: minimal (<5%) |
| Half-life | 1.2-1.5 hours in healthy adults; prolonged in renal impairment (e.g., up to 6-8 hours in severe renal failure) |
| Protein binding | 65-80% bound to plasma proteins (mainly albumin) |
| Volume of Distribution | 0.23-0.35 L/kg; distributes well into body fluids and tissues including skin, soft tissue, and respiratory tract |
| Bioavailability | Oral: 90-95% |
| Onset of Action | Oral: peak serum concentrations reached in 1.5-2 hours; clinical effect begins within 1-2 hours |
| Duration of Action | Approximately 6-12 hours depending on infection site and renal function; dosing every 12 hours typical |
| Action Class | Cephalosporins: 1st generation |
| Brand Substitutes | Adrocef 500mg Tablet, Pandrox 500mg Tablet, Aroxil 500mg Tablet, Safedrox 500mg Tablet, Drox 500mg Tablet |
500 mg orally twice daily for 10 days; for uncomplicated skin infections, 250 mg twice daily or 500 mg once daily.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-49 mL/min: 250 mg twice daily; CrCl 10-29 mL/min: 250 mg once daily; CrCl <10 mL/min: 250 mg every 48 hours. |
| Liver impairment | No dose adjustment required for mild to moderate hepatic impairment; not studied in severe impairment. |
| Pediatric use | 6 months to 12 years: 30 mg/kg/day divided twice daily (max 1 g/day); for pharyngitis/tonsillitis: 20 mg/kg/day divided twice daily (max 500 mg/day). |
| Geriatric use | Adjust dose based on renal function; no specific geriatric dose adjustments other than renal considerations. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CEFZIL (CEFZIL).
| Breastfeeding | Cefprozil (CEFZIL) is excreted in human milk in low amounts. Milk-to-plasma ratio is approximately 0.3. Considered compatible with breastfeeding; however, monitor infant for potential gastrointestinal effects. |
| Teratogenic Risk | FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, but no adequate human studies. Risk cannot be ruled out. First trimester: No reported teratogenicity in animal studies; clinical data insufficient. Second/third trimester: No known risk; use only if clearly needed. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to cefprozil or other cephalosporins","Immediate-type hypersensitivity to penicillins (cross-reactivity risk)"]
| Precautions | ["Hypersensitivity reactions (including anaphylaxis) in penicillin-allergic patients","Clostridium difficile-associated diarrhea (CDAD)","Seizures with high doses or renal impairment","Hemolytic anemia (rare)","Prolonged prothrombin time (rare)"] |
| Food/Dietary | No clinically significant food interactions. High-fat meals may slightly delay absorption but do not affect overall absorption extent. Avoid alcohol during therapy as it may increase risk of disulfiram-like reaction (rare with cephalosporins). |
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| Fetal Monitoring |
| No specific monitoring required beyond standard prenatal care. Observe for maternal allergic reactions or gastrointestinal disturbances. Fetal monitoring not indicated unless for maternal condition. |
| Fertility Effects | No known adverse effects on fertility in animal studies. Clinical data lacking. |
| Clinical Pearls | CEFZIL (cefprozil) is a second-generation cephalosporin with activity against Gram-positive cocci (including Streptococcus pyogenes, Streptococcus pneumoniae, and methicillin-susceptible Staphylococcus aureus) and some Gram-negative bacteria (Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli). It has a longer half-life (1.3 hours) compared to cephalexin, allowing twice-daily dosing. It is FDA-approved for acute sinusitis, pharyngitis/tonsillitis, otitis media, acute bacterial exacerbation of chronic bronchitis, secondary bacterial infection of acute bronchitis, and uncomplicated skin and skin structure infections. Note that it is not reliable against penicillin-resistant S. pneumoniae or beta-lactamase-producing H. influenzae (though it is more stable than first-generation agents). In penicillin-allergic patients, cross-reactivity risk is low but not zero (avoid if immediate-type hypersensitivity to penicillin). Dose adjustment required for creatinine clearance <30 mL/min: give standard dose every 12 hours for first dose, then 50% of standard dose every 12 hours. Available as 250 mg and 500 mg tablets and as an oral suspension (125 mg/5 mL or 250 mg/5 mL). Refrigerate suspension after reconstitution; discard after 14 days. |
| Patient Advice | Take this medication exactly as prescribed by your doctor, usually every 12 hours. · You may take this medication with or without food; however, taking with food may help reduce stomach upset. · Complete the full course of therapy, even if you feel better, to reduce the risk of antibiotic resistance. · Shake the oral suspension well before each dose. Use a proper measuring spoon or dosing syringe to ensure accurate dose. · Store the oral suspension in the refrigerator (not freezer) and discard any unused portion after 14 days. · Notify your doctor if you develop diarrhea, especially if it is watery or bloody; do not use anti-diarrhea medications without consulting your doctor. · Seek immediate medical attention if you experience signs of an allergic reaction: rash, hives, itching, difficulty breathing, tightness in chest, swelling of face/mouth/tongue. · Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding. |