Drug Levels and Effects:

Summary of Use during Lactation:

Fluoroquinolones such as norfloxacin have traditionally not been used in infants because of concern about adverse effects on the infants' developing joints. However, recent studies indicate little risk.[1][2] In addition, the calcium in milk might prevent absorption of the small amounts of fluoroquinolones in milk,[3] but insufficient data exist to prove or disprove this assertion. The serum and milk levels and oral bioavailability of norfloxacin are the lowest of any of the fluoroquniolones, so the risk to the infant should be minimal. Short-term use of norfloxacin is acceptable in nursing mothers.

Drug Levels:

Maternal Levels.

Norfloxacin was undetectable in milk at any time up to 6 hours after a single 200 mg oral dose.[4] Milk levels have not been measured after repeated administration.

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

Relevant published information was not found as of the revision date.

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.

Alternate Drugs to Consider:



1. Gurpinar AN, Balkan E, Kilic N et al. The effects of a fluoroquinolone on the growth and development of infants. J Int Med Res. 1997;25:302-6. PMID:9364293
2. van den Oever HL, Versteegh FG, Thewessen EA et al. Ciprofloxacin in preterm neonates: case report and review of the literature. Eur J Pediatr. 1998;157:843-5. PMID:9809826
3. Fleiss PM. The effect of maternal medications on breast-feeding infants. J Hum Lact. 1992;8:7. Letter. PMID:1558663
4. Takase Z, Shirafuji H, Uchida M. Basic and clinical studies on AM-715 in the field of obstetrics and gynecology. Chemotherapy (Tokyo). 1981;29 (Suppl 4):697-704.

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antiinfective Agents

  • Antibacterial Agents

  • Quinolones

  • Fluoroquinolones

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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