Is Norfloxacin (a fluoroquinolone antibiotic) safe to use during the first trimester of pregnancy?

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Last updated: April 27, 2025View editorial policy

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From the Guidelines

Norfloxacin should be avoided during the first trimester of pregnancy due to potential risks to fetal development, and safer alternative antibiotics should be used whenever possible. The use of fluoroquinolones, including norfloxacin, during pregnancy has been a topic of concern due to potential risks to the fetus. Animal studies have shown that fluoroquinolones can affect developing cartilage and may cause arthropathy (joint disease) 1. Although human data specifically on norfloxacin is limited, the general approach is to use safer alternative antibiotics during pregnancy whenever possible.

If treatment for urinary tract or other infections is needed during the first trimester, medications with better established safety profiles such as penicillins, cephalosporins, or nitrofurantoin (except at term) are preferred options. The potential risks of norfloxacin include cartilage damage, potential impacts on bone development, and other developmental concerns. According to the European Respiratory Journal, ciprofloxacin, another fluoroquinolone, is possibly safe during pregnancy, but most clinicians try to avoid it during pregnancy and lactation 1.

Given the potential risks and the availability of safer alternatives, the use of norfloxacin during the first trimester of pregnancy should be avoided. The decision to use any medication during pregnancy should always involve careful consideration of the benefits versus risks, and norfloxacin should only be used if the potential benefit justifies the potential risk to the fetus and if safer alternatives are not appropriate or effective. Some key points to consider when making this decision include:

  • The potential risks to the fetus, including cartilage damage and developmental concerns
  • The availability of safer alternative antibiotics
  • The importance of careful consideration of the benefits and risks of using norfloxacin during pregnancy.

From the FDA Drug Label

Pregnancy Teratogenic Effects Pregnancy Category C Ofloxacin has not been shown to have any teratogenic effects at oral doses as high as 810 mg/kg/day (11 times the recommended maximum human dose based on mg/m2 or 50 times based on mg/kg) and 160 mg/kg/day (4 times the recommended maximum human dose based on mg/m2 or 10 times based on mg/kg) when administered to pregnant rats and rabbits, respectively. Ofloxacin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus (see WARNINGS).

The use of Norfloxacin in the first trimester of pregnancy should be approached with caution. Although animal studies have not shown teratogenic effects, there are no adequate and well-controlled studies in pregnant women. Therefore, Norfloxacin should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus 2.

From the Research

Norfloxacin Use in First Trimester

  • Norfloxacin is a type of fluoroquinolone antibiotic, and its use during pregnancy, especially in the first trimester, has been a topic of concern due to potential risks to the fetus 3, 4.
  • Studies have shown that fluoroquinolones, including norfloxacin, are generally avoided in pregnancy due to the potential risk of congenital abnormalities and other adverse effects 3, 4.
  • However, some studies suggest that the risk of adverse effects may be lower than previously thought, and that norfloxacin may be used in pregnancy when clearly indicated, although caution is still advised, especially in the first trimester 5, 6.
  • A meta-analysis found no association between quinolones, including norfloxacin, and fetal malformations, preterm delivery, stillbirth, or miscarriage, although larger studies are needed to establish safety 6.
  • The use of norfloxacin during breastfeeding is also considered to be relatively safe, although caution is still advised 7.

Key Considerations

  • Physiologic changes in pregnancy can lead to pharmacokinetic alterations in antibiotics, including norfloxacin, which may require dose adjustment or careful monitoring and assessment 3, 7.
  • The selection of an antibiotic during pregnancy should be based on the likely pathogen, stage of pregnancy, and safety of the drug, as well as the potential risks and benefits of treatment 4, 7.
  • Healthcare professionals should consider the teratogenic and toxic risk profiles of antibiotics, including norfloxacin, when making prescribing decisions for pregnant and lactating women 7.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

A Review of Antibiotic Use in Pregnancy.

Pharmacotherapy, 2015

Research

[Should fluoroquinolones be feared during pregnancy and breastfeeding?].

Gynecologie, obstetrique, fertilite & senologie, 2022

Research

The safety of quinolones and fluoroquinolones in pregnancy: a meta-analysis.

BJOG : an international journal of obstetrics and gynaecology, 2018

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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