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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: March 17, 2021.

Estimated reading time: 1 minute

CASRN: 7261-97-4

image 134987695 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

Because no information is available on the long-term use of dantrolene during breastfeeding, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. After short-term use, the drug would be expected to be eliminated from milk in 1 to 2 days.

Drug Levels

Maternal Levels. Administration of several intravenous dantrolene doses were given over 3 days to a postpartum mother in divided doses. Total daily dosages were 720 mg on day 1, 320 mg on day 2, and 80 mg on day 3. A milk level of 1.2 mg/L was measured on day 2 after a total of 640 mg had been given. The milk level was 50 mcg/L on day 4 about 35 hours after the last dose. Dantrolene half-life in milk was 9.2 hours.[1]

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



Fricker RM, Hoerauf KH, Drewe J, et al. Secretion of dantrolene into breast milk after acute therapy of a suspected malignant hyperthermia crisis during cesarean section. Anesthesiology. 1998;89:1023–5. [PubMed: 9778021]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Muscle Relaxants, Central

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: NBK501309PMID: 30000368


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