What are the first-line empirical antibiotics for Urinary Tract Infection (UTI) in a pregnant patient?

From the Guidelines

Nitrofurantoin is the first-line empirical antibiotic for Urinary Tract Infection (UTI) in a pregnant patient.

First-line Treatment Options

• Nitrofurantoin macrocrystals: 50–100 mg q.i.d. for 5 days 1
• Nitrofurantoin monohydrate or macrocrystals: 100 mg b.i.d. for 5 days 1
• Nitrofurantoin macrocrystals prolonged release: 100 mg b.i.d. for 5 days 1
• Fosfomycin trometamol: 3 g single dose, although its use in pregnancy is not as well-studied as nitrofurantoin 1

Rationale

The European Association of Urology guidelines recommend nitrofurantoin as a first-line treatment for uncomplicated cystitis in women, including pregnant women 1. The American College of Physicians also recommends nitrofurantoin for 5 days as a best practice advice for uncomplicated bacterial cystitis in women 1. However, it is essential to note that trimethoprim and trimethoprim-sulfamethoxazole are not recommended in the first trimester and last trimester of pregnancy, respectively 1.

Considerations

The optimal duration of therapy will be antimicrobial-specific, and nitrofurantoin and β-lactam antimicrobials are preferred due to their safety in pregnant women 1. A single dose of fosfomycin is effective for clearance of bacteria in the urine, but its use in pregnancy requires further study 1.

From the Research

First-Line Empirical Antibiotics for UTI in Pregnant Patients

• The first-line empirical antibiotics for urinary tract infection (UTI) in pregnant patients are:
  • Fosfomycin, due to its high sensitivity to the drug, ease of use, and safety for use in pregnancy 2
  • Nitrofurantoin, which has been shown to have 93-100% sensitivity for each of the three trimesters 2
• Other options may include:
  • Trimethoprim-sulfamethoxazole (TMP-SMX), although its use may be limited due to increasing resistance among community-acquired Escherichia coli 3
  • Fluoroquinolones, which may be considered as alternative first-line agents, but their use may be limited due to potential adverse effects and resistance prevalence 3

Considerations for Antibiotic Selection

• When selecting an antibiotic for UTI treatment in pregnant patients, factors to consider include:
  • Pharmacokinetics and spectrum of activity of the antimicrobial agent
  • Resistance prevalence for the community
  • Potential for adverse effects
  • Duration of therapy
  • Primary excretion routes through the urinary tract to achieve high urinary drug levels 3, 4
• It is essential to use antimicrobials wisely to avoid resistance development, especially in the treatment of UTIs caused by multidrug-resistant (MDR) organisms 4

Special Considerations for Pregnant Women

• Pregnant women with UTIs require special consideration, as the infection can pose a risk to both the mother and the fetus
• The choice of antibiotic should be based on the most up-to-date evidence and guidelines, taking into account the safety and efficacy of the medication during pregnancy 2, 5