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 hospital-managed infections, with a well-established efficacy and safety profile supported by extensive clinical use.
Features
- Active ingredient: Cefixime (as trihydrate)
- Pharmacological class: Third-generation cephalosporin antibiotic
- Mechanism of action: Inhibition of bacterial cell wall synthesis via binding to penicillin-binding proteins (PBPs)
- Spectrum: Broad-spectrum activity against Gram-positive and Gram-negative bacteria
- Formulation: Available as tablets, chewable tablets, and oral suspension
- Bioavailability: Approximately 40–50% following oral administration
- Half-life: 3–4 hours in patients with normal renal function
- Excretion: Primarily renal, with some biliary elimination
Benefits
- Effective against common respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis
- High clinical cure rates in uncomplicated urinary tract infections caused by Escherichia coli and Proteus mirabilis
- Convenient once-daily or twice-daily dosing regimen improves patient compliance
- Generally well-tolerated with a lower incidence of serious adverse effects compared to some other antibiotic classes
- Suitable for pediatric populations when prescribed in appropriate formulations and dosages
- Oral administration avoids the need for intravenous access in appropriate clinical scenarios
Common use
Cefixime is commonly prescribed for the treatment of acute bacterial exacerbations of chronic bronchitis, community-acquired pneumonia, acute otitis media, pharyngitis, tonsillitis, and uncomplicated urinary tract infections. It is also used in the management of uncomplicated gonorrhea and as an alternative agent for salmonellosis and shigellosis in specific clinical contexts. The antibiotic demonstrates particular utility in infections caused by beta-lactamase-producing strains of H. influenzae and M. catarrhalis.
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, 400 mg twice daily may be appropriate. Pediatric dosing is typically 8 mg/kg/day, administered either once daily or in two divided doses. 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. Dosage adjustments are 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. Renal function should be assessed before initiation and monitored during therapy, especially in elderly patients or those with pre-existing renal impairment. Prolonged use may result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs during therapy, appropriate measures should be taken. Patients should be advised that antibacterial drugs, including cefixime, should only be used to treat bacterial infections and not viral infections such as the common cold.
Contraindications
Cefixime is contraindicated in patients with known hypersensitivity to cefixime, other cephalosporins, or any component of the formulation. Cross-sensitivity with penicillins and other beta-lactam antibiotics may occur; caution is advised in patients with penicillin allergy. The antibiotic is not recommended in patients with a history of severe immediate hypersensitivity reactions to any cephalosporin.
Possible side effect
Common adverse reactions include diarrhea (16%), nausea (7%), abdominal pain (3%), and headache (2%). Less frequently reported effects include dyspepsia, flatulence, vomiting, and transient elevations in liver enzymes. Rare but serious side effects may include pseudomembranous colitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, anaphylaxis, and blood dyscrasias such as thrombocytopenia, leukopenia, and eosinophilia. Any signs of hypersensitivity reactions require immediate discontinuation and appropriate medical intervention.
Drug interaction
Probenecid may decrease renal tubular secretion of cefixime, resulting in increased and prolonged blood levels. Concurrent administration with carbamazepine may increase carbamazepine levels, potentially leading to toxicity. Cefixime may enhance the anticoagulant effect of warfarin, requiring close monitoring of prothrombin time. The antibiotic may reduce the efficacy of oral contraceptives; additional contraceptive methods are recommended during therapy. False-positive reactions for glucose in the urine may occur with Benedict’s or Fehling’s solutions but not with enzyme-based tests.
Missed dose
If a dose is missed, it should be taken as soon as remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed administration. Consistent adherence to the prescribed regimen is important to maintain effective antibiotic concentrations and prevent the development of resistance.
Overdose
Symptoms of overdose may include nausea, vomiting, epigastric distress, and diarrhea. In cases of significant overdose, hemodialysis or peritoneal dialysis may aid in the removal of cefixime from the bloodstream. There is no specific antidote for cefixime overdose; treatment should be symptomatic and supportive. Gastric lavage may be considered if performed soon after ingestion. Serum levels and renal function should be monitored in cases of substantial overdose.
Storage
Store at controlled room temperature (20–25°C or 68–77°F). Protect from light and moisture. Keep the container tightly closed. The reconstituted oral suspension is stable for 14 days when refrigerated (2–8°C or 36–46°F); any unused portion should be discarded after this period. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging.
Disclaimer
This information is provided for educational purposes only and does not constitute medical advice. The prescribing physician should be consulted for diagnosis and treatment decisions. Dosage and administration should be determined by a qualified healthcare professional based on the patient’s specific clinical condition, microbial susceptibility, and renal function. The full prescribing information should be reviewed before initiation of therapy.
Reviews
Clinical studies have demonstrated cefixime’s efficacy with cure rates of 85–95% in respiratory tract infections and 90–95% in uncomplicated urinary tract infections. The antibiotic is generally well-rated by healthcare providers for its convenient dosing schedule and broad spectrum of activity. Some clinicians note the higher cost compared to first-line alternatives, while others value its utility in penicillin-allergic patients (with appropriate caution). Patient satisfaction surveys indicate good tolerance, though gastrointestinal side effects remain the most commonly reported concern.