Bupivacaine Pharmacokinetics and Breast Milk Excretion of Liposomal Bupivacaine Administered after Cesarean Birth

Hiba J. Mustafa, Henry L. Wong, Mahmoud Al-Kofahi, Malinda Schaefer, Ashwin Karanam, Michael M. Todd

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

OBJECTIVE:To evaluate bupivacaine concentrations in maternal plasma and transfer into breast milk in women undergoing liposomal bupivacaine infiltration in the transversus abdominis plane after cesarean birth.METHODS:Prospective cohort study of healthy pregnant women who underwent cesarean birth at term followed by a transversus abdominis plane block using 52 mg bupivacaine hydrochloride 0.25% (20 mL) and 266 mg liposomal bupivacaine 1.3% (20 mL). Simultaneous blood and milk samples were collected in a staggered fashion, three to four samples per patient at the following timepoints after block administration: 2, 6, 12, 24, 48, 72, and 96 hours. Quantification of bupivacaine was performed by liquid chromatography-tandem mass spectrometry. Neonatal drug exposure was modeled by calculating milk/plasma area under the curve (AUC) ratios, neonatal dosage, and relative neonatal dosage of bupivacaine at each sampling time.RESULTS:Thirty patients were enrolled. Concentrations in breast milk peaked at 6 hours (mean 58 ng/mL), followed by constant and steady decline to low levels at 96 hours (mean 5.2 ng/mL). Maternal plasma concentrations had two peaks, first at 6 hours (mean 155.9 ng/mL) and then at 48 hours (mean 225.8 ng/mL), followed by steady decline. Milk/plasma AUC0-tratios ranged between AUC0-2of 0.45 (80% CI 0.38-0.52) and AUC0-96of 0.15 (80% CI 0.14-0.17). Neonatal dosage ranged between a mean of 355.9 ng/kg at 0-2 hours and a mean of 15,155.4 ng/kg at 0-96 hours. Relative neonatal dosage was less than 1% at all time intervals. No serious adverse reactions occurred in any neonate.CONCLUSION:Bupivacaine is excreted in breast milk after local infiltration of liposomal bupivacaine and bupivacaine hydrochloride mixture into transversus abdominis plane blocks after cesarean birth. Relative neonatal dosages of less than 1% (less than 10% is considered to be unlikely to be of clinical concern) suggest minimal risks for breastfeeding healthy, term neonates after the administration of this combination of local anesthetics to mothers.CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT03526419.

Original languageEnglish (US)
Pages (from-to)70-76
Number of pages7
JournalObstetrics and gynecology
Volume136
Issue number1
DOIs
StatePublished - Jul 2020

Bibliographical note

Funding Information:
Research reported in this publication was supported by Thrasher Research Fund CON00000000080211. Each author has confirmed compliance with the journal’s requirements for authorship.

Publisher Copyright:
© 2020 Lippincott Williams and Wilkins. All rights reserved.

Fingerprint

Dive into the research topics of 'Bupivacaine Pharmacokinetics and Breast Milk Excretion of Liposomal Bupivacaine Administered after Cesarean Birth'. Together they form a unique fingerprint.

Cite this