Cefixime

 

1. Generic & Brand Names

• Generic: Cefixime

• Brands: Suprax® (Global), Fixit® (India), Cefspan® (Japan)

• Formulations:

  • Tablets (200mg, 400mg)

  • Oral suspension (100mg/5mL after reconstitution)

  • No IV/IM formulations

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2. Drug Class & Mechanism

• Class: 3rd-generation oral cephalosporin

• Mechanism: Inhibits bacterial cell wall synthesis → bactericidal

• Spectrum:

  • Gram-negative: H. influenzae, M. catarrhalis, E. coli, P. mirabilis, N. gonorrhoeae

  • Gram-positive: S. pneumoniae (penicillin-susceptible only), S. pyogenes

  • NOT for: MRSA, Pseudomonas, Enterococci

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3. FDA-Approved Uses

Infection Type	Key Pathogens	First-Line?
Otitis Media (AOM)	H. influenzae, M. catarrhalis	Alternative
Pharyngitis/Tonsillitis	S. pyogenes (Group A Strep)	Penicillin-allergic patients
Uncomplicated UTI	E. coli, P. mirabilis	Last-line (resistance concerns)
Acute Bronchitis	H. influenzae, M. catarrhalis	Avoid (usually viral)
Gonorrhea	N. gonorrhoeae (uncomplicated)	Dual therapy only

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4. Dosing Regimens

Infection Type	Adult Dose	Pediatric Dose (≥6 mo)
AOM/Pharyngitis	400 mg daily	8 mg/kg/day in 1-2 doses
Uncomplicated UTI	400 mg daily x 7 days	Not recommended <12 years
Gonorrhea	400 mg single dose + Azithromycin 1g	N/A
Renal Adjustment:

• CrCl 20-59 mL/min: ↓ dose by 25%

• CrCl <20 mL/min: ↓ dose by 50%

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5. Resistance Concerns

Pathogen	Resistance Rate (US)	Clinical Implication
S. pneumoniae	25-40%	Avoid for pneumonia
E. coli (UTI)	20-35%	Use only if susceptible
H. influenzae	10-15% (β-lactamase+)	Combine with clavulanate?
N. gonorrhoeae	5-10%	Always dual therapy

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6. Side Effects

Common (≥10%)	Serious (<1%)
Diarrhea	Anaphylaxis (cross-reacts with penicillin)
Loose stools	C. difficile colitis
Nausea	Stevens-Johnson Syndrome
Vaginal candidiasis	Hepatotoxicity
Headache	Interstitial Nephritis

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7. Black Box Warnings & Contraindications

• 🚫 Absolute Contraindications:

  • Anaphylaxis to penicillins/cephalosporins (10% cross-reactivity)

  • Severe renal impairment without dose adjustment

• High-Risk Groups:

  • Penicillin-allergic: Test skin if IgE-mediated history

  • Elderly: ↑ C. difficile risk (avoid if recent antibiotics)

  • Pregnancy (Category B): Use only if benefit > risk

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8. Drug Interactions

Medication	Effect	Management
Carbamazepine	↑ Levels → toxicity	Monitor serum levels
Warfarin	↑ INR → bleeding	Monitor INR
Probenecid	↑ Cefixime levels	Avoid combo

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9. Clinical Use Cases

Scenario	Recommendation
Strep throat in penicillin-allergic patient	400 mg daily x 10 days
Uncomplicated UTI with susceptible E. coli	400 mg daily x 7 days
AOM after amoxicillin failure	8 mg/kg/day x 10 days
Gonorrhea	Single 400 mg dose + Azithromycin 1g

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10. Storage & Administration

• Suspension:

  • Reconstitute with water → yields 100mg/5mL

  • Refrigerate (discard after 14 days)

• Tablets:

  • Store at 15-30°C (59-86°F)

• Take with/without food (food delays absorption)

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Key Limitations & Alternatives

Diagram

Code

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Why It's Falling Out of Favor

• UTIs: Rising E. coli resistance (>30% in some regions)

• Respiratory: Ineffective against penicillin-resistant pneumococci

• Gonorrhea: CDC recommends ceftriaxone IM as first-line (higher efficacy)

Stewardship Tip: Reserve for culture-confirmed susceptible infections when first-line agents contraindicated.

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Patient Counseling Points

1. "Complete full course – even if symptoms improve."

2. Diarrhea warning: "Stop drug if watery/bloody stools appear."

3. Allergy alert: "Seek ER for hives/swelling/difficulty breathing."

4. Suspension: "Shake well; use measuring device (not spoon)."

💡 Pro Tip: For penicillin-allergic patients with anaphylaxis history, avoid all β-lactams – use macrolides (azithromycin) instead.