What is the appropriate cefixime dosing regimen for an otherwise healthy pregnant woman with an uncomplicated urinary tract infection and normal renal function?

Cefixime Dosing for UTI in Pregnancy

For uncomplicated urinary tract infections in pregnancy, cefixime 400 mg once daily for 7 days is an effective and safe treatment option, though it is not a first-line agent according to current guidelines.

First-Line Agents Should Be Prioritized

Current guidelines recommend the following as first-line therapy for uncomplicated UTI in pregnancy 1:

• Fosfomycin trometamol 3 g as a single oral dose – most convenient option 1
• Nitrofurantoin 100 mg twice daily for 5-7 days – avoid after 36 weeks gestation due to neonatal hemolysis risk 1
• Amoxicillin 500 mg three times daily for 3-7 days – when organism is susceptible 1

When Cefixime Is Appropriate

Cefixime serves as a reasonable alternative when first-line agents are contraindicated or when resistance to other antibiotics is documented 2. The recommended dosing is:

• Cefixime 400 mg once daily for 7 days 3
• Can be given as 200 mg twice daily to reduce gastrointestinal side effects 4

Evidence Supporting Cefixime Use

• A randomized controlled trial in 112 pregnant women with asymptomatic bacteriuria demonstrated 94.8% eradication rates with cefixime 400 mg daily for 7 days, with significantly fewer adverse reactions (1.7%) compared to amoxicillin/clavulanate (13%) 3
• Cefixime demonstrates high sensitivity against E. coli, the primary uropathogen in pregnancy 5
• Pharmacokinetic parameters remain stable during pregnancy with <1% penetration into fetal tissues 2
• The dispersible formulation (Cefixime EXPRESS) provides improved tolerability and adherence 2

Critical Trimester-Specific Contraindications to Avoid

When cefixime is not suitable, be aware of these absolute contraindications 1:

• First trimester: Avoid trimethoprim (folate antagonism, neural tube defects)
• Third trimester: Avoid sulfonamides (neonatal kernicterus risk)
• All trimesters: Avoid fluoroquinolones (fetal cartilage concerns)
• G6PD deficiency: Avoid nitrofurantoin and sulfonamides (hemolytic anemia risk)

Mandatory Follow-Up

A repeat urine culture 7 days after completing therapy is mandatory to confirm microbiological cure, given high recurrence rates in pregnancy 1. If treatment fails, culture-guided therapy with an alternative agent for a full 7-day course is required 1.

Common Pitfalls

• Initiating empirical therapy without obtaining urine culture first – culture with susceptibility testing is mandatory before treatment in pregnancy 1
• Using once-daily 400 mg dosing without counseling about increased GI side effects – consider split dosing 4
• Failing to verify eradication with post-treatment culture 1
• Treating asymptomatic bacteriuria as if the patient were not pregnant – treatment is clearly indicated in pregnancy due to pyelonephritis and preterm labor risks 1