Cefixime: Potent Oral Cephalosporin for Bacterial Infections
Cefixime
Cefixime is a third-generation cephalosporin antibiotic renowned for its broad-spectrum activity against Gram-negative and Gram-positive bacteria. It operates by inhibiting bacterial cell wall synthesis, leading to bacterial cell death. This oral medication is particularly valued for its once-daily dosing convenience and high bioavailability, making it a preferred choice for treating various community-acquired infections. Its stability against beta-lactamases enhances its efficacy where other antibiotics may fail.
Features
- Active ingredient: Cefixime (as trihydrate)
- Drug class: Third-generation cephalosporin antibiotic
- Administration: Oral (tablets, chewable tablets, oral suspension)
- Mechanism: Inhibits bacterial cell wall synthesis
- Spectrum: Broad-spectrum activity against Gram-positive and Gram-negative bacteria
- Bioavailability: 40–50% (oral administration)
- Half-life: 3–4 hours
- Excretion: Primarily renal
Benefits
- Effective against a wide range of bacterial pathogens, including beta-lactamase-producing strains
- Convenient once-daily dosing improves patient adherence
- High clinical cure rates in respiratory, urinary, and ENT infections
- Well-tolerated profile with a low incidence of severe adverse effects
- Suitable for pediatric and adult populations
- Oral formulation avoids the need for intravenous administration in many cases
Common use
Cefixime is indicated for the treatment of mild to moderate infections caused by susceptible strains of designated microorganisms. Common uses include acute bacterial exacerbations of chronic bronchitis, community-acquired pneumonia, acute otitis media, pharyngitis, tonsillitis, uncomplicated urinary tract infections, and uncomplicated gonorrhea. It is also used off-label for certain enteric infections, including typhoid fever and shigellosis, when susceptibility is confirmed.
Dosage and direction
The recommended dosage of cefixime varies based on the infection type, severity, patient age, and renal function. For adults and children ≥12 years or ≥50 kg: 400 mg once daily, or 200 mg every 12 hours. For otitis media: 8 mg/kg/day in a single dose or divided every 12 hours (max 400 mg/day). For uncomplicated gonorrhea: single 400 mg dose. Oral suspension should be shaken well before use. Take with or without food; administration with food may minimize gastrointestinal upset. Dosage adjustment is necessary in patients with renal impairment (creatinine clearance <60 mL/min).
Precautions
Use with caution in patients with a history of gastrointestinal disease, particularly colitis. Prolonged use may result in superinfection or fungal overgrowth. Cefixime should be prescribed with care in patients with known hypersensitivity to beta-lactam antibiotics. Use during pregnancy only if clearly needed (Category B). Excreted in human milk; caution advised when administering to nursing women. Monitor renal function periodically during prolonged therapy. False-positive reactions for glucose in the urine may occur with Benedict’s or Fehling’s solutions.
Contraindications
Cefixime is contraindicated in patients with known hypersensitivity to cefixime, any cephalosporin, or any component of the formulation. Avoid use in patients with a history of severe hypersensitivity reactions (e.g., anaphylaxis) to penicillins or other beta-lactam antibiotics due to potential cross-reactivity.
Possible side effect
Common side effects include diarrhea (5–16%), nausea (3–7%), abdominal pain (2–4%), headache (2%), dizziness (1%), and flatulence (1%). Less frequently, rash, pruritus, urticaria, and transient elevations in liver enzymes may occur. Serious but rare adverse effects include pseudomembranous colitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, anaphylaxis, hemolytic anemia, and interstitial nephritis. Discontinue use if severe diarrhea or allergic reactions occur.
Drug interaction
Probenecid may inhibit renal excretion of cefixime, increasing serum concentrations. Concurrent use with carbamazepine may increase carbamazepine levels, risking toxicity. Cefixime may enhance the anticoagulant effect of warfarin; monitor INR closely. Concomitant use with potent diuretics may increase the risk of nephrotoxicity. Antacids containing aluminum or magnesium may reduce absorption; administer cefixime at least 2 hours before or after such agents.
Missed dose
If a dose is missed, take it as soon as remembered. If it is near the time of the next dose, skip the missed dose and resume the regular dosing schedule. Do not double the dose to catch up. Consistent dosing is important to maintain effective antibiotic levels.
Overdose
Symptoms of overdose may include nausea, vomiting, epigastric distress, diarrhea, and convulsions (especially in patients with renal impairment). Treatment is supportive and symptomatic. Hemodialysis may aid in removal of cefixime (approximately 50% removed in 4 hours). In case of suspected overdose, seek immediate medical attention.
Storage
Store tablets at controlled room temperature (20–25°C). Keep oral suspension refrigerated (2–8°C) before reconstitution; after reconstitution, store at room temperature or refrigerate and discard unused portion after 14 days. Keep container tightly closed. Protect from light and moisture. Keep out of reach of children.
Disclaimer
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Do not disregard professional medical advice or delay in seeking it because of something you have read here.
Reviews
Clinical studies and post-marketing surveillance demonstrate high efficacy and tolerability of cefixime. In a meta-analysis of respiratory tract infections, clinical success rates exceeded 90%. Patients frequently report satisfaction with once-daily dosing and minimal disruption to daily activities. Healthcare providers appreciate its reliable spectrum and oral bioavailability, often noting its utility as a step-down therapy from intravenous cephalosporins. Long-term safety data support its use in both adult and pediatric populations.