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

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

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Last Revision: August 15, 2023.

Estimated reading time: 1 minute

CASRN: 144689-24-7

image 135114358 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

With the exception of one adverse reaction in a breastfed infant, no information is available on the use of olmesartan during breastfeeding. An alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Drug Levels

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

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

Effects in Breastfed Infants

A 6-day-old healthy full-term newborn was exposed to olmesartan in breastmilk. The maternal dose of olmesartan and extent of nursing were not reported. Weight gain was normal during the first two weeks of life, but at the pediatric checkup on the 17th day postpartum, an abrupt decrease in body weight was recorded. He was hospitalized on the 21st day, and mixed feeding with milk and formula was started. Biochemical examinations showed aspartate-aminotransferase (AST) 250 mg/dL, and regular urinalysis. Virologic and metabolic causes of elevated transaminase were ruled out. The baby started to regain weight and his AST gradually normalized to 50 mg/dL by the 24th day. Olmesartan intake was stopped and the child was discharged on the 24th day of life.[1]

Effects on Lactation and Breastmilk

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

Alternate Drugs to Consider

Candesartan, Captopril, Benazepril, Enalapril, Quinapril


Salimova M, Maggi M, Crevani M, et al. Olmesartan-induced reversible transaminase elevation in a breastfed newborn. A case report. Neurotoxicol Teratol 2023;98:24. doi:10.1016/j.ntt.2023.107236 [CrossRef]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Milk, Human

Antihypertensive Agents

Angiotensin II Type 1 Receptor Blockers

Angiotensin Receptor Blockers


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: NBK501627PMID: 30000688


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