CEFIXIME
Clinical safety rating: safe
Human studies have proved safety
Cefixime is a third-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.
| Metabolism | Cefixime is not significantly metabolized; it is primarily excreted unchanged in the urine and bile. |
| Excretion | Renal excretion of unchanged drug accounts for 50-60% of elimination; biliary/fecal elimination accounts for 10-20%. |
| Half-life | Terminal elimination half-life is 3-4 hours in patients with normal renal function; extends to 11-15 hours in moderate renal impairment (CrCl 20-40 mL/min) and up to 20 hours in severe impairment. |
| Protein binding | Approximately 65-70% bound primarily to albumin. |
| Volume of Distribution | Volume of distribution is 0.3-0.5 L/kg, indicating distribution primarily into extracellular fluid. |
| Bioavailability | Oral suspension: 40-50%; tablets: 40-50% (fasting) but increased to 50-60% with food. |
| Onset of Action | Oral: Therapeutic concentrations in plasma achieved within 2-4 hours after oral administration. |
| Duration of Action | Approximately 12-24 hours for susceptible organisms based on MIC, supporting once-daily dosing. |
400 mg orally once daily or 200 mg orally every 12 hours for 7–14 days; uncomplicated gonorrhea: 400 mg orally as a single dose
| Dosage form | TABLET |
| Renal impairment | CrCl 30–59 mL/min: 300 mg orally once daily; CrCl 15–29 mL/min: 200 mg orally once daily; CrCl <15 mL/min or hemodialysis: 200 mg orally once daily |
| Liver impairment | Mild to moderate hepatic impairment (Child-Pugh A or B): no adjustment necessary; severe hepatic impairment (Child-Pugh C): limited data, use with caution |
| Pediatric use | Children ≥6 months: 8 mg/kg/day orally divided every 12–24 hours; maximum 400 mg/day; for pharyngitis/tonsillitis: 8 mg/kg/day as a single dose or divided every 12 hours for 10 days |
| Geriatric use | No specific dose adjustment; monitor renal function; use lowest effective dose due to potential age-related renal decline |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Probenecid may decrease cephalosporin excretion May cause diarrhea including Clostridium difficile-associated diarrhea.
| Breastfeeding | Cefixime is excreted into human milk in low concentrations. M/P ratio not established. Considered compatible with breastfeeding due to minimal oral bioavailability in infants; monitor for diarrhea and rash. |
| Teratogenic Risk | FDA Pregnancy Category B. No evidence of teratogenicity in animal studies. Limited human data; no increased risk of major malformations reported. Caution in first trimester due to lack of robust data. |
| Fetal Monitoring |
■ FDA Black Box Warning
No FDA black box warnings.
| Common Effects | Diarrhea |
| Serious Effects |
["Hypersensitivity to cefixime or any cephalosporin.","Severe hypersensitivity to penicillins (cross-sensitivity possible)."]
| Precautions | ["Hypersensitivity reactions, including anaphylaxis.","Clostridium difficile-associated diarrhea (CDAD).","Decreased renal function requires dose adjustment.","Potential for superinfection with prolonged use."] |
| Food/Dietary | Take cefixime with or without food; food does not affect absorption. Avoid alcohol during therapy as it may exacerbate gastrointestinal side effects or cause disulfiram-like reaction (rare with cephalosporins). Maintain adequate fluid intake to prevent crystalluria. |
Loading safety data…
| Monitor maternal renal function and signs of hypersensitivity. Fetal monitoring is not routinely required unless maternal infection poses risk to fetus. |
| Fertility Effects | No known adverse effects on fertility based on animal studies. No human data available. |
| Clinical Pearls | Cefixime is an oral third-generation cephalosporin with activity against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, and many Enterobacteriaceae. It is not active against Pseudomonas aeruginosa, Enterococcus, or methicillin-resistant Staphylococcus aureus. Use for uncomplicated gonorrhea as a single 400 mg oral dose. Monitor for hypersensitivity reactions, especially in penicillin-allergic patients (cross-reactivity ~10%). Dose adjustment required for CrCl <30 mL/min (maximum 300 mg/day). Avoid in patients with cephalosporin or severe penicillin allergy. Can cause false-positive Coombs test and urinary glucose tests using copper reduction (e.g., Clinitest). |
| Patient Advice | Take exactly as prescribed; complete the full course even if you feel better to prevent bacterial resistance. · For gonorrhea, a single dose is usually effective; you may need a follow-up test to confirm cure. · This medication may cause diarrhea; contact your doctor if it becomes severe, watery, or bloody. · If you experience rash, hives, difficulty breathing, or swelling of face/tongue/throat, seek emergency medical attention. · Do not breastfeed without consulting your doctor, as cefixime passes into breast milk. · Inform your doctor if you have a history of penicillin allergy, kidney disease, or colitis. · Cefixime may cause false-positive results on certain urine glucose tests; use glucose oxidase methods (e.g., Clinistix) instead. |