What is the dosage and treatment duration of Cefixime for various bacterial infections?

Cefixime Dosing and Treatment Duration

Standard Adult Dosing

The FDA-approved dose of cefixime for adults is 400 mg daily, which can be administered as a single daily dose or divided into 200 mg twice daily. 1

• The 400 mg capsule may be taken without regard to food 1
• For infections caused by Streptococcus pyogenes, treatment must continue for at least 10 days to prevent rheumatic fever and glomerulonephritis 1

Pediatric Dosing (≥6 months old)

Children should receive 8 mg/kg/day of the oral suspension, administered either as a single daily dose or divided into 4 mg/kg every 12 hours. 1

• Children weighing >45 kg or older than 12 years should receive the standard adult dose of 400 mg daily 1
• For otitis media specifically, the suspension formulation must be used rather than tablets or capsules, as the suspension achieves higher peak blood levels at equivalent doses 1
• Efficacy and safety have not been established in infants <6 months of age 1

Renal Impairment Dosing

Dose adjustment is required when creatinine clearance falls below 60 mL/min: 1

• CrCl ≥60 mL/min: Normal dose (400 mg daily)
• CrCl 21-59 mL/min OR hemodialysis: 260 mg daily (13 mL of 100 mg/5 mL suspension or 6.5 mL of 200 mg/5 mL suspension)
• CrCl ≤20 mL/min OR peritoneal dialysis: 172 mg daily (8.6 mL of 100 mg/5 mL suspension or 4.4 mL of 200 mg/5 mL suspension)
• Neither hemodialysis nor peritoneal dialysis removes significant amounts of cefixime 1

Specific Infection Indications and Durations

Uncomplicated Gonorrhea (Cervical/Urethral)

Cefixime should NOT be used as first-line therapy for gonorrhea due to declining susceptibility and suboptimal cure rates. 2, 3

• If ceftriaxone is unavailable, use cefixime 400 mg orally as a single dose PLUS azithromycin 1 g orally 3
• Cefixime achieves only 97.1-97.4% cure rates for urogenital/anorectal gonorrhea compared to 99.1% for ceftriaxone 2
• Pharyngeal gonorrhea cure rate is only 91% with cefixime—avoid use for pharyngeal infections 2, 3
• Mandatory test-of-cure at 1 week is required when cefixime is used 3
• The CDC recommends against cefixime monotherapy due to rising minimum inhibitory concentrations (MICs), particularly in the Western United States and among men who have sex with men 2, 3

Uncomplicated Urinary Tract Infections

Cefixime 400 mg daily can be used for uncomplicated UTIs, though it provides lower blood and urinary concentrations than IV cephalosporins. 4, 1

• Treatment duration typically 7-10 days for uncomplicated cystitis 5, 6
• Urine culture and susceptibility testing should guide therapy 4
• Should not be used empirically in areas with high resistance rates 4

Pharyngitis and Tonsillitis

For streptococcal pharyngitis, cefixime 400 mg daily (adults) or 8 mg/kg/day (children) must be continued for at least 10 days. 1

• Clinical cure rates of 98.2% have been demonstrated in pediatric streptococcal pharyngitis 6
• The 10-day duration is critical to prevent rheumatic fever complications 1

Acute Exacerbations of Chronic Bronchitis

Cefixime 400 mg daily for 7-14 days is effective for acute bacterial exacerbations of chronic bronchitis. 1, 7

• Clinical success rates of 86-88% have been demonstrated 7
• Effective against Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae 7, 8

Otitis Media (Pediatric)

Children with acute otitis media should receive 8 mg/kg/day of cefixime suspension for 10 days. 1, 5

• The suspension formulation is mandatory—do not substitute tablets or capsules 1
• Comparable efficacy to cefaclor 20-40 mg/kg/day and amoxicillin 40 mg/kg/day 5

Enteric Fever (Typhoid)

The WHO recommends cefixime 8 mg/kg/day as a single daily dose for children >28 days, or 400 mg once daily for adults, for 7-14 days. 2

• However, cefixime showed significantly more treatment failures and longer fever duration compared to fluoroquinolones in randomized trials 2
• Consider alternative agents when available 2

Important Clinical Caveats

Pharmacokinetic Limitations

Cefixime provides lower and less sustained bactericidal levels than injectable ceftriaxone despite similar antimicrobial spectrum. 2, 4, 3

• The 3-4 hour half-life permits once or twice daily dosing 5, 8
• Peak concentration (Cmax) of 4.4 mcg/mL exceeds MIC90 for susceptible pathogens 8

Adverse Effects

Diarrhea and loose stools are the most common adverse effects, occurring in 16-24% of patients. 1, 9, 6

• These effects are usually mild to moderate, transient, and occur in the first few days of treatment 5, 9
• Drug discontinuation due to adverse effects occurs in only 1.9-2% of patients 9, 6
• Clostridioides difficile-associated diarrhea can occur and requires evaluation if diarrhea develops 1

Spectrum Limitations

Cefixime has poor activity against Staphylococcus aureus, enterococci, Listeria monocytogenes, and Pseudomonas species. 5, 9

• Excellent activity against beta-lactamase-producing strains of H. influenzae, N. gonorrhoeae, and Enterobacteriaceae 5, 8
• Inactive against Pseudomonas aeruginosa 5, 9

Hypersensitivity Considerations

Cross-reactivity with penicillins occurs in up to 10% of penicillin-allergic patients—use with caution. 1

• Anaphylactic reactions including shock and fatalities have been reported 1
• Discontinue immediately if allergic reaction occurs 1