U.S. flag

An official website of the United States government

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Drugs and Lactation Database (LactMed®) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006-.

Cover of Drugs and Lactation Database (LactMed®)

Drugs and Lactation Database (LactMed®) [Internet].

Show details


Last Revision: February 15, 2021.

Estimated reading time: 2 minutes

CASRN: 32986-56-4

image 135000193 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

Tobramycin is poorly excreted into breastmilk. Newborn infants apparently absorb small amounts of other aminoglycosides, but serum levels with typical three times per day dosages are far below those attained when treating newborn infections and systemic effects of tobramycin are unlikely. Older infants would be expected to absorb even less tobramycin. Because there is little variability in the milk tobramycin levels during multiple daily dose regimens, timing breastfeeding with respect to the dose is of little or no benefit in reducing infant exposure. Data are not available with single daily dose regimens. Monitor the infant for possible effects on the gastrointestinal flora, such as diarrhea, candidiasis (e.g., thrush, diaper rash) or rarely, blood in the stool indicating possible antibiotic-associated colitis.

Maternal use of an ear drop or eye drop that contains tobramycin presents little or no risk for the nursing infant.[1] A task force respiratory experts from Europe, Australia and New Zealand found that inhaled tobramycin is compatible with breastfeeding.[2]

Drug Levels

Maternal Levels. After a single 80 mg intramuscular dose of tobramycin in 5 women, milk levels were measured every hour for 6 hours. Only trace levels were detected in 4 of the samples from 1 to 8 hours after the dose. In the fifth woman, milk levels ranged from 0.4 to 0.52 mg/L over 8 hours, with the highest level found at 4 hours after the dose.[3]

In one patient who received 80 mg of tobramycin every 8 hours by intramuscular injection, milk levels were 0.6 mg/L 1 hour after the dose and 0.58 mg/L 8 hours after the dose.[4]

At 2 months postpartum, a woman was receiving intravenous tobramycin 150 mg 3 times daily plus meropenem for cystic fibrosis. Four days after beginning, milk tobramycin levels were undetectable (<0.18 mg/L) before the infusion and in 6 milk samples taken from 1 to 5 hours after the infusion.[5]

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

Effects in Breastfed Infants

An infant was breastfed (extent not stated) until the 4th month postpartum. At 2 months of age, his mother was given a 2-week course of tobramycin 150 mg three times daily plus meropenem for a cystic fibrosis exacerbation. infant displayed no change in stool pattern during the maternal treatment and had normal renal function at 6 months of age.[5,6]

Effects on Lactation and Breastmilk

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


Niebyl JR. Use of antibiotic of ear, nose, and throat disorders in pregnancy and lactation. Am J Otolaryngol. 1992;13:187–92. [PubMed: 1503194]
Middleton PG, Gade EJ, Aguilera C, et al. ERS/TSANZ Task Force Statement on the management of reproduction and pregnancy in women with airways diseases. Eur Respir J. 2020;55:1901208. [PubMed: 31699837]
Takase Z, Shirafuji H, Uchida M, et al. Laboratory and clinical studies on tobramycin in the field of obstetrics and gynecology. Chemotherapy (Tokyo). 1975;23:1402–7.
Uwaydah M, Bibi S, Salman S. Therapeutic efficacy of tobramycin--a clinical and laboratory evaluation. J Antimicrob Chemother. 1975;1:429–37. [PubMed: 1107297]
Festini F, Ciuti R, Taccetti G, et al. Breast-feeding in a woman with cystic fibrosis undergoing antibiotic intravenous treatment. J Matern Fetal Neonatal Med. 2006;19:375–6. [PubMed: 16801316]
Festini F, Ciuti R, Repetto T, et al. Safety of breast-feeding during an IV tobramycin course for infants of CF women. Pediatr Pulmonol Suppl 2004;38:288-9. Abstract. doi: 10.1002/ppul.20143. [CrossRef]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Anti-Infective Agents

Antibacterial Agents


Disclaimer: Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.

Copyright Notice

Attribution Statement: LactMed is a registered trademark of the U.S. Department of Health and Human Services.

Bookshelf ID: NBK501115PMID: 30000174


Related information

Similar articles in PubMed

  • Review Kanamycin.[Drugs and Lactation Database (...]
    Review Kanamycin.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Amikacin.[Drugs and Lactation Database (...]
    Review Amikacin.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Streptomycin.[Drugs and Lactation Database (...]
    Review Streptomycin.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Gentamicin.[Drugs and Lactation Database (...]
    Review Gentamicin.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Paromomycin.[Drugs and Lactation Database (...]
    Review Paromomycin.
    . Drugs and Lactation Database (LactMed®). 2006
See reviews...See all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...