Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AVYCAZ vs ANSPOR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
AVYCAZ is a combination of ceftazidime, a cephalosporin beta-lactam antibiotic, and avibactam, a non-beta-lactam beta-lactamase inhibitor. Ceftazidime inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis. Avibactam protects ceftazidime from degradation by certain beta-lactamases, including Ambler class A, class C, and some class D enzymes.
Cephalexin is a first-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.
Complicated intra-abdominal infections (c IAI) in combination with metronidazole,Complicated urinary tract infections (c UTI) including pyelonephritis,Hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP)
FDA-approved: Treatment of respiratory tract infections, otitis media, skin and skin structure infections, bone infections, genitourinary tract infections caused by susceptible bacteria.,Off-label: Prosthetic joint infections, dental infections, endocarditis prophylaxis.
1 vial (ceftazidime 2g and avibactam 0.5g) IV over 2 hours every 8 hours.
250-500 mg orally every 6 hours for 10-14 days; maximum 4 g/day.
Ceftazidime: ~2.8 hours; avibactam: ~2.7 hours. Extended in renal impairment (e.g., Cr Cl <50 m L/min requires dose adjustment).
1.5–2 hours in adults with normal renal function; prolonged to 20–30 hours in severe renal impairment (Cr Cl <10 m L/min)
Ceftazidime is primarily excreted unchanged by the kidneys via glomerular filtration. Avibactam is also primarily eliminated renally and undergoes minimal metabolism. The metabolism of both components is not significantly mediated by cytochrome P450 enzymes.
Cephalexin is not extensively metabolized; it is primarily excreted unchanged in the urine. Minor hepatic metabolism may occur.
Ceftazidime: primarily renal (80-90% unchanged); avibactam: primarily renal (85-95% unchanged). Fecal excretion <1%.
Primarily renal (90–95%) as unchanged drug via glomerular filtration and tubular secretion; biliary excretion negligible (<1%)
Ceftazidime: ~10% bound to albumin; avibactam: ~8% bound to human plasma proteins.
10–20% bound to serum albumin
Ceftazidime: ~0.19 L/kg; avibactam: ~0.29 L/kg. Indicates extensive distribution into extracellular fluid.
0.13–0.22 L/kg; indicates distribution primarily into extracellular fluid
IV only; bioavailability is 100%.
Oral: 75–90% (well absorbed); IM: 100%
Cr Cl 31-50 m L/min: 1 vial IV q8h; Cr Cl 16-30 m L/min: 1 vial IV q12h; Cr Cl 6-15 m L/min: 1 vial IV q24h; Cr Cl ≤5 m L/min: 1 vial IV q48h.
Cr Cl 10-50 m L/min: 250 mg every 12-24 hours. Cr Cl <10 m L/min: 250 mg every 24-48 hours.
No dosage adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not studied in severe hepatic impairment (Child-Pugh C).
No specific adjustment recommended; monitor for adverse effects in severe impairment.
Not approved for pediatric patients under 18 years of age.
12.5-25 mg/kg orally every 6 hours; maximum 50 mg/kg/day.
Dose based on renal function, as per adult renal adjustment; no specific age-related adjustments.
Start at lower end of dosing range; monitor renal function and adjust based on Cr Cl.
No black box warning for AVYCAZ.
No FDA boxed warning exists for cephalexin.
Hypersensitivity: Serious and occasionally fatal hypersensitivity reactions (anaphylaxis) have been reported in patients receiving beta-lactam antibiotics.,Clostridioides difficile-associated diarrhea (CDAD): Has been reported with nearly all antibacterial agents and may range in severity from mild diarrhea to fatal colitis.,Direct Coombs test seroconversion: Positive direct Coombs test may develop during treatment, potentially interfering with crossmatching.,Central nervous system (CNS) adverse reactions: Including seizures, encephalopathy, and myoclonus have been reported, particularly in patients with renal impairment or higher doses.,Renal impairment: Dose adjustment required based on creatinine clearance.,Hepatotoxicity: Elevations of liver enzymes have been observed.,Nephrotoxicity: Concurrent use with nephrotoxic agents may increase risk.
Hypersensitivity reactions including anaphylaxis.,Clostridioides difficile-associated diarrhea (CDAD).,Dosage adjustment required in renal impairment.,Seizures with high doses or renal failure.,Potential for superinfection with prolonged use.
Known hypersensitivity to ceftazidime, avibactam, or other cephalosporins,Severe hypersensitivity (e.g., anaphylaxis) to any other beta-lactam antibacterial agents
Known hypersensitivity to cephalosporins or penicillins (cross-sensitivity).,Previous immediate hypersensitivity reaction to penicillins.
No significant food interactions. However, alcohol should be avoided due to potential disulfiram-like reaction (nausea, vomiting, flushing, headache).
Iron-fortified infant formula and iron supplements may reduce absorption; take at least 2 hours apart. No other significant food interactions. Avoid alcohol.
AVYCAZ (ceftazidime-avibactam) is classified as FDA Pregnancy Category B. Animal reproduction studies in rats and rabbits at doses up to 1.6 times the human dose revealed no evidence of fetal harm. However, there are no adequate and well-controlled studies in pregnant women. Ceftazidime crosses the placenta. Risk cannot be ruled out; use only if clearly needed.
Cefradine (ANSPOR) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, and adequate well-controlled studies in pregnant women are lacking. No evidence of teratogenicity; however, caution is advised. First trimester: no known risk; second and third trimesters: no known fetal adverse effects.
Ceftazidime is excreted in human milk in low concentrations; avibactam excretion is unknown. The M/P ratio for ceftazidime is approximately 0.02. Caution is advised due to potential disruption of infant gut flora. Consider benefits of breastfeeding versus risk of infant exposure.
Cefradine is excreted into human breast milk in low concentrations. M/P ratio is approximately 0.12–0.20. Considered compatible with breastfeeding by the American Academy of Pediatrics; however, monitor infant for potential diarrhea or allergic reaction.
No specific dose adjustments are recommended for pregnancy. Physiological changes in pregnancy (e.g., increased volume of distribution, enhanced renal clearance) may alter pharmacokinetics, but data are insufficient to recommend routine dose modification. Monitor clinical response and consider therapeutic drug monitoring if available.
Increased renal clearance during pregnancy may lower serum concentrations of cefradine. Standard dosing (250–500 mg every 6 hours) is generally adequate; however, for severe infections, consider higher doses or more frequent administration based on clinical response. No specific dose adjustment is routinely recommended, but monitoring therapeutic efficacy is advised.
AVYCAZ (ceftazidime-avibactam) is a beta-lactam/beta-lactamase inhibitor combination active against ESBLs, KPC, and OXA-48 carbapenemases. It is not active against metallo-beta-lactamases (e.g., NDM, VIM). Dose adjustment required for creatinine clearance <50 m L/min. Monitor for hypersensitivity reactions, including anaphylaxis. Can cause positive direct Coombs test without hemolysis.
ANSPOR (cefdinir) is a third-generation oral cephalosporin with activity against Gram-positive and Gram-negative bacteria. It is stable in the presence of some beta-lactamases. Dose adjustment required for Cr Cl <30 m L/min. Avoid use in patients with immediate hypersensitivity to penicillins due to cross-reactivity (approx 10%). Administer with iron supplements or iron-fortified infant formula at least 2 hours apart to reduce chelation. Suspension should be refrigerated and discarded after 10 days.
Take exactly as prescribed; complete full course even if feeling better.,Inform your doctor if you have kidney disease; blood tests may be needed to adjust dose.,Report any signs of allergic reaction (rash, hives, difficulty breathing, swelling).,May cause diarrhea; tell your doctor if severe or persistent.,Avoid alcohol during treatment and for 72 hours after last dose due to possible disulfiram-like reaction.
Take exactly as prescribed, even if you feel better.,Complete the full course of therapy.,If using suspension, shake well before each dose. Refrigerate and discard after 10 days.,Avoid alcohol while taking this medication.,Notify your doctor if you experience diarrhea, rash, or signs of allergic reaction.,Take iron supplements or iron-fortified infant formula at least 2 hours apart from ANSPOR.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about AVYCAZ vs ANSPOR, answered by our medical review team.
AVYCAZ is a Cephalosporin Antibiotic that works by AVYCAZ is a combination of ceftazidime, a cephalosporin beta-lactam antibiotic, and avibactam, a non-beta-lactam beta-lactamase inhibitor. Ceftazidime inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis. Avibactam protects ceftazidime from degradation by certain beta-lactamases, including Ambler class A, class C, and some class D enzymes.. ANSPOR is a Cephalosporin Antibiotic that works by Cephalexin is a first-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AVYCAZ and ANSPOR depend on the specific clinical indication. These are both Cephalosporin Antibiotic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of AVYCAZ is: 1 vial (ceftazidime 2g and avibactam 0.5g) IV over 2 hours every 8 hours.. The standard adult dose of ANSPOR is: 250-500 mg orally every 6 hours for 10-14 days; maximum 4 g/day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between AVYCAZ and ANSPOR in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. AVYCAZ is classified as Category C. AVYCAZ (ceftazidime-avibactam) is classified as FDA Pregnancy Category B. Animal reproduction studies in rats and rabbits at doses up to 1.6 times the human dose revealed no eviden. ANSPOR is classified as Category C. Cefradine (ANSPOR) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, and adequate well-controlled studies in pregnant women are lacking. N. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.