Skip to main content

Tolbutamide use while Breastfeeding

Medically reviewed by Last updated on Oct 12, 2023.

Drugs containing Tolbutamide: Orinase, Tol-Tab

Tolbutamide Levels and Effects while Breastfeeding

Summary of Use during Lactation

Tolbutamide is no longer marketed in the United States. It is excreted into breastmilk in small amounts that should cause no harm to the breastfed infant. Monitor breastfed infants for signs of hypoglycemia such as jitteriness, excessive sleepiness, poor feeding, seizures cyanosis, apnea, or hypothermia. If there is concern, monitoring of the breastfed infant's blood glucose is advisable during maternal therapy with hypoglycemic agents.[1,2]

Drug Levels

Maternal Levels. In 2 women who were 3 days postpartum, milk levels were measured 4 hours after ingestion of a 500 mg dose of tolbutamide. Milk levels averaged 18 mg/L in one and 3 mg/L in the other.[3]

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.

Effects on Lactation and Breastmilk

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

Alternate Drugs to Consider

Acarbose, Glipizide, Glyburide, Insulin, Metformin, Miglitol


Everett JA. Use of oral antidiabetic agents during breastfeeding. J Hum Lact 1997;13:319-21. [PubMed: 9429368]
Berlin CM, Briggs GG. Drugs and chemicals in human milk. Semin Fetal Neonatal Med 2005;10:149-59. [PubMed: 15701580]
Moiel RH, Ryan JR. Tolbutamide Orinase in human breast milk. Clin Pediatr (Phila) 1967;8:480. [PubMed: 6029660]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Milk, Human

Hypoglycemic Agents

Sulfonylurea Compounds

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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.