What is the recommended dose of cefixime (Cefixime) for a 14-year-old girl weighing 44 kg with positive typhoid fever?

Cefixime Dosage for Typhoid Fever in a 14-year-old Girl Weighing 44 kg

For a 14-year-old girl weighing 44 kg with positive typhoid fever, the recommended dose of cefixime is 400 mg daily (either as a single daily dose or 200 mg twice daily) for 7-10 days. 1

Dosage Calculation and Rationale

The FDA-approved dosing for cefixime in pediatric patients is based on weight:

• For patients weighing 45.1 kg or greater: 400 mg daily 1
• For patients weighing 40.1 to 45 kg: 350 mg daily 1

Since this patient weighs 44 kg, she falls into the 40.1-45 kg category, which would technically call for 350 mg daily. However:

1. The patient is 14 years old, which is at the upper end of pediatric age range
2. The FDA label states that "Children weighing more than 45 kg or older than 12 years should be treated with the recommended adult dose" 1
3. The adult dose for cefixime is 400 mg daily 1

Therefore, the 400 mg adult dose is appropriate for this 14-year-old patient.

Administration Options

Cefixime can be administered as:

• 400 mg once daily, OR
• 200 mg twice daily (divided dose)

For typhoid fever, the medication can be given with or without food, as the FDA label states that "the capsule may be administered without regard to food" 1.

Treatment Duration

For typhoid fever, treatment should continue for 7-10 days 2. Clinical improvement typically occurs within 48-72 hours of starting appropriate therapy, but the full course should be completed to prevent relapse.

Evidence for Cefixime in Typhoid Fever

Cefixime has shown good efficacy in treating typhoid fever:

• A study demonstrated a 90% clinical cure rate with cefixime in children with culture-positive typhoid fever 3
• Another study showed 95% clinical cure with an 8-day regimen of oral cefixime in children with multidrug-resistant typhoid fever 4

Alternative Treatment Options

If cefixime is unavailable or contraindicated, alternative options include:

1. Azithromycin: 20 mg/kg/day (maximum 1g/day) for 7 days 2, 5

   • Has shown higher cure rates (85%) compared to cefixime (71%) in some studies 5
   • May have shorter fever clearance time

2. Ceftriaxone: 50-80 mg/kg/day IV (maximum 2g/day) for 7-10 days 2

   • Preferred for severe infections or when oral therapy isn't possible

Important Considerations

• Monitoring: Assess clinical response within 48-72 hours; fever should begin to resolve
• Resistance patterns: Local resistance patterns should be considered when selecting therapy 2
• Renal function: If the patient has renal impairment (creatinine clearance <60 mL/min), dose adjustment would be necessary 1
• Side effects: Most common are diarrhea and stool changes, which are usually mild to moderate and transient 6

Pitfalls to Avoid

1. Underdosing: Using weight-based dosing without considering age can lead to underdosing in adolescents
2. Premature discontinuation: Stopping therapy when symptoms improve but before completing the full course can lead to relapse
3. Ignoring resistance patterns: Failing to consider local resistance patterns when selecting therapy
4. Antimotility agents: Avoid using antimotility agents like loperamide in typhoid fever as they may worsen outcomes 2

In conclusion, for this 14-year-old girl weighing 44 kg with typhoid fever, cefixime 400 mg daily for 7-10 days is the appropriate dosage.