Last update Aug. 1, 2022

Naloxone Hydrochloride

Likely Compatibility

Fairly safe. Mild or unlikely adverse effects. Compatible under certain circumstances. Follow-up recommended. Read Commentary.

It is an opioid antagonist used to reverse respiratory and neurological depression induced by opioid overdose. It acts by blocking the opioid receptors, not on the concentration or elimination of the opioid drug involved. Intravenous, intramuscular, subcutaneous or intranasal administration.

Since the last update we have not found published data on its excretion in breastmilk.

Its pharmacokinetic data do not allow to predict a possible excretion in breast milk.

Given the low plasma levels of Naloxone after a treatment dose (<0,1micrograms/mL)the maximum concentration that it would reach in breast milk would imply a theoretical dose for the infant that is much lower than that used in Pediatrics.

Its null oral bioavailability prevents the passage to the infant's plasma from ingested breast milk.

Experts authors consider the use of this medication to be probably compatible during breastfeeding (Hale, LactMed, Briggs 2015, ASGE 2012, Mahadevan 2006); temporary interruption of breastfeeding will depend on opiate elimination and maternal symptoms, not on naloxone. (Hale, LactMed, Briggs 2015)


We do not have alternatives for Naloxone Hydrochloride.

Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Naloxone Hydrochloride is also known as

Naloxone Hydrochloride in other languages or writings:


Main tradenames from several countries containing Naloxone Hydrochloride in its composition:


Variable Value Unit
Oral Bioavail. ≈ 0 %
Molecular weight 400 daltons
Protein Binding 45 %
VD 2.86 l/Kg
pKa 10.07 -
Tmax 0.05 - 0.25 hours
1 - 1.5; intranasal: 1.8 - 2.7 hours


  1. LactMed. Drugs and Lactation Database (LactMed). Internet. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: 2006 - Consulted on April 16, 2024 Full text (link to original source)
  2. Hale TW. Medications & Mothers' Milk. 1991- . Springer Publishing Company. Available from Consulted on April 10, 2024 Full text (link to original source)
  3. Briggs GG, Freeman RK, Towers CV, Forinash AB. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. Wolters Kluwer Health. Tenth edition (acces on line) 2015
  4. ASGE Standard of Practice Committee., Shergill AK, Ben-Menachem T, Chandrasekhara V, Chathadi K, Decker GA, Evans JA, Early DS, Fanelli RD, Fisher DA, Foley KQ, Fukami N, Hwang JH, Jain R, Jue TL, Khan KM, Lightdale J, Pasha SF, Sharaf RN, Dominitz JA, Cash BD. Guidelines for endoscopy in pregnant and lactating women. Gastrointest Endosc. 2012 Jul;76(1):18-24. Abstract Full text (link to original source) Full text (in our servers)
  5. Mahadevan U, Kane S. American gastroenterological association institute technical review on the use of gastrointestinal medications in pregnancy. Gastroenterology. 2006 Jul;131(1):283-311. Review. Abstract Full text (link to original source) Full text (in our servers)

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