From the Guidelines
For a urinary tract infection with positive nitrates at 36+5 weeks gestation, nitrofurantoin is the recommended first-line treatment due to its safety and efficacy in late pregnancy 1.
Treatment Options
- Nitrofurantoin 100 mg orally twice daily for 7 days is a suitable option, as it is considered safe in late pregnancy and effectively treats most urinary pathogens.
- Alternatives include sulfonamides, but their use should be guided by urine culture results and local resistance patterns.
Importance of Treatment
- Untreated UTIs during pregnancy can progress to pyelonephritis and increase risks of preterm labor, so prompt treatment is essential 1.
- Completing the full course of antibiotics is crucial, even if symptoms improve, to ensure resolution of the infection.
Additional Recommendations
- Urine culture should be collected before starting antibiotics to confirm the infection and guide therapy if needed.
- Increased fluid intake and urinating frequently can help manage symptoms.
- Follow-up urine culture after completing treatment is recommended to ensure resolution of the infection.
- If symptoms worsen or include fever, flank pain, or nausea/vomiting, immediate medical attention is needed as this may indicate progression to pyelonephritis.
Key Considerations
- The optimal duration of antimicrobial therapy for treatment of bacteriuria in pregnant women has not been determined, but a 7-day course is commonly recommended 1.
- Screening for bacteriuria by urine culture at least once in early pregnancy is recommended to identify and treat asymptomatic bacteriuria, reducing the risk of pyelonephritis and other complications 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Antibiotic Treatment for Urinary Tract Infection
- The patient is at 36 + 5 weeks gestation with a positive nitrates test, indicating a potential urinary tract infection (UTI) 2.
- According to the study published in the American Journal of Obstetrics and Gynecology, first-line treatments for UTI include nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole (when resistance levels are <20%) 2.
- Nitrofurantoin is a widely used antibiotic for treating UTIs, with a high susceptibility to common UTI pathogens 3.
Efficacy and Safety of Nitrofurantoin
- A systematic review and meta-analysis found that nitrofurantoin is effective in preventing UTIs, with a risk ratio of 0.38 in favor of nitrofurantoin compared to no prophylaxis 4.
- However, the use of nitrofurantoin may be associated with increased non-severe adverse effects, such as gastrointestinal and central nervous system symptoms 4, 5.
- A cohort study comparing 100 mg and 50 mg nitrofurantoin prophylaxis found that 50 mg may have a better safety profile, with a lower hazard of cough, dyspnea, and nausea 6.
Treatment Recommendations
- Based on the available evidence, nitrofurantoin can be considered a suitable treatment option for UTI in pregnancy, particularly at 36 + 5 weeks gestation 2, 3.
- The choice of nitrofurantoin dosage (50 mg or 100 mg) should be based on individual patient factors, with consideration of the potential benefits and risks of each regimen 6.