Cefixime: Potent Oral Cephalosporin for Bacterial Infections
Cefixime is a third-generation cephalosporin antibiotic indicated for the treatment of a wide range of bacterial infections. It exerts its bactericidal effect by inhibiting bacterial cell wall synthesis, leading to the eradication of susceptible pathogens. This oral formulation offers a convenient and effective therapeutic option for both community-acquired and certain healthcare-associated infections, providing broad-spectrum coverage with reliable pharmacokinetic properties.
Features
- Active ingredient: Cefixime (as trihydrate)
- Drug class: Third-generation cephalosporin antibiotic
- Administration: Oral (tablets and oral suspension)
- Mechanism: Inhibition of bacterial cell wall synthesis
- Spectrum: Broad-spectrum activity against Gram-positive and Gram-negative bacteria
- Bioavailability: 40-50% (not significantly affected by food)
- Half-life: Approximately 3-4 hours
- Excretion: Primarily renal (50-60% unchanged)
Benefits
- Effective against β-lactamase producing strains of Haemophilus influenzae and Neisseria gonorrhoeae
- Convenient once-daily or twice-daily dosing regimen improves patient compliance
- Excellent tissue penetration, particularly in respiratory tissues and urine
- Demonstrated clinical efficacy in treating otitis media, pharyngitis, and urinary tract infections
- Lower incidence of Clostridium difficile-associated diarrhea compared to broader-spectrum antibiotics
- Suitable for both adult and pediatric populations (≥6 months)
Common use
Cefixime is commonly prescribed for the treatment of acute bacterial exacerbations of chronic bronchitis, acute community-acquired pneumonia, otitis media, pharyngitis and tonsillitis (particularly streptococcal infections), uncomplicated urinary tract infections, and uncomplicated gonorrhea. It is also used as an alternative agent for patients with penicillin allergies (excluding those with immediate hypersensitivity reactions) and for the treatment of susceptible Enterobacteriaceae infections.
Dosage and direction
The recommended adult dosage is 400 mg daily, administered as a single dose or in two divided doses of 200 mg every 12 hours. For severe infections or those caused by less susceptible organisms, the dose may be increased to 400 mg every 12 hours. Pediatric dosing is based on weight: 8 mg/kg/day, either as a single dose or divided every 12 hours (maximum 400 mg daily). The oral suspension should be shaken well before administration. Cefixime may be taken with or without food, though administration with food may enhance tolerance in some patients. Treatment duration typically ranges from 7 to 14 days depending on the infection type and severity.
Precautions
Use with caution in patients with renal impairment (creatinine clearance <60 mL/min requires dosage adjustment). Monitor for superinfection and pseudomembranous colitis during and after treatment. Exercise caution in patients with history of gastrointestinal disease, particularly colitis. May result in false-positive reactions for glucose in the urine using Benedict’s or Fehling’s solution. Prolonged use may result in overgrowth of nonsusceptible organisms. Use in pregnancy only if clearly needed (Category B). Cefixime is excreted in human milk; caution should be exercised when administering to nursing women.
Contraindications
Known hypersensitivity to cefixime, other cephalosporins, or any component of the formulation. Patients with history of anaphylactic reactions to penicillins or other β-lactam antibiotics should not receive cefixime due to cross-reactivity potential. Contraindicated in patients with phenylketonuria (oral suspension contains aspartame).
Possible side effect
Common adverse reactions include diarrhea (16%), nausea (7%), abdominal pain (3%), dyspepsia (3%), and flatulence (4%). Less frequently reported effects include headache (2%), dizziness (1%), and transient elevations in liver enzymes. Serious but rare side effects include pseudomembranous colitis, anaphylaxis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and blood dyscrasias (neutropenia, thrombocytopenia). Vaginal candidiasis and oral thrush may occur due to alteration of normal flora.
Drug interaction
Probenecid may decrease renal tubular secretion of cefixime, increasing serum concentrations. Carbamazepine levels may be increased when co-administered with cefixime. May enhance the anticoagulant effect of warfarin (monitor INR closely). Concomitant use with potent diuretics may increase the risk of nephrotoxicity. Chloramphenicol may antagonize the bactericidal effect of cefixime. False-positive urinary glucose tests may occur with copper reduction methods.
Missed dose
If a dose is missed, it should be taken as soon as remembered. However, if it is almost time for the next dose, the missed dose should be skipped and the regular dosing schedule resumed. Doubling the dose to make up for a missed dose is not recommended. Maintain approximately equal intervals between doses to ensure consistent therapeutic levels.
Overdose
Symptoms of overdose may include nausea, vomiting, epigastric distress, diarrhea, and convulsions (particularly in patients with renal impairment). Treatment is supportive and symptomatic. Hemodialysis may remove cefixime from the circulation (approximately 50% removal in 4 hours). In cases of significant overdose, particularly in patients with renal compromise, consider hemodialysis. Monitor renal function and provide appropriate electrolyte management.
Storage
Store tablets at controlled room temperature (20-25°C/68-77°F) in a tightly closed container. Protect from light and moisture. Reconstituted oral suspension should be stored at room temperature and used within 14 days. Do not freeze. Keep all medications out of reach of children and pets. Dispose of unused medication properly according to local regulations.
Disclaimer
This information is provided for educational purposes only and does not constitute medical advice. The prescribing physician should be consulted for specific medical advice, diagnoses, and treatment recommendations. Individual patient response to cefixime may vary based on multiple factors including age, renal function, and infection characteristics. Always follow the prescribed dosage and complete the full course of therapy unless otherwise directed by a healthcare professional.
Reviews
Clinical studies demonstrate cefixime’s efficacy with cure rates of 85-95% for otitis media, 90-97% for pharyngitis/tonsillitis, and 85-98% for uncomplicated urinary tract infections. Meta-analyses confirm its non-inferiority to other oral cephalosporins for respiratory tract infections. Patient satisfaction surveys indicate high compliance rates due to the convenient dosing schedule. However, increasing resistance patterns among Streptococcus pneumoniae and other pathogens necessitate ongoing susceptibility testing. The drug is generally well-tolerated, with most adverse effects being mild and self-limiting.