What antibiotics are safe for pregnant women with bacterial diarrhea?

Safe Antibiotics for Pregnant Women with Bacterial Diarrhea

For pregnant women with bacterial diarrhea, ampicillin, cefotaxime, ceftriaxone, or trimethoprim-sulfamethoxazole (TMP-SMZ) are the recommended first-line antibiotics, while fluoroquinolones should be avoided. 1

First-Line Antibiotics for Bacterial Diarrhea in Pregnancy

Safe Options

• Ampicillin is considered a first-line antibiotic treatment during pregnancy with established safety profile 2
• Cephalosporins (cefotaxime, ceftriaxone) are safe first-line options during pregnancy 1
• TMP-SMZ can be used for bacterial diarrhea in pregnancy, particularly for Salmonella infections 1

Treatment Algorithm

1. Initial assessment: Determine severity of diarrhea (presence of blood, fever, dehydration)
2. First-line treatment:
   • Ampicillin (FDA pregnancy category B) for mild to moderate infections 3, 2
   • Ceftriaxone or cefotaxime for more severe infections 1
3. Alternative treatment: TMP-SMZ if penicillins or cephalosporins cannot be used 1

Antibiotics to Avoid During Pregnancy

• Fluoroquinolones (including ciprofloxacin) should not be used during pregnancy 1
• Tetracyclines are contraindicated after the fifth week of pregnancy 2
• Aminoglycosides should be avoided due to associated nephrotoxicity and ototoxicity 2

Special Considerations

Salmonella Infections

• Pregnant women with Salmonella gastroenteritis should receive treatment to prevent extraintestinal spread that could lead to placental infection and pregnancy loss 1
• Recommended antibiotics for Salmonella in pregnancy include ampicillin, cefotaxime, ceftriaxone, or TMP-SMZ 1

Traveler's Diarrhea

• TMP-SMZ might offer some protection against traveler's diarrhea in pregnant women 1
• Prophylactic antibiotics are generally not recommended for travelers, but may be considered for HIV-infected travelers depending on immunosuppression level and travel destination 1

Physiological Considerations

• Pregnancy causes physiological changes that affect antibiotic pharmacokinetics:
  • Increased glomerular filtration rate
  • Increased total body volume
  • Enhanced cardiac output 4
• These changes may necessitate dose adjustments or careful monitoring 4

Important Caveats

• Initiation of antimicrobial therapy must be based on clear necessity, as any antibiotic chosen will expose both mother and fetus 5
• Maternal serum levels of antibiotics may be reduced by 10-50% in late pregnancy 6
• Most antibiotics cross the placenta and are excreted in breast milk 6
• Treatment should be initiated promptly in cases of severe diarrhea, especially with blood in stool or high fever 1