Last update Aug. 16, 2022


Likely Compatibility

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

Pentazocine is an opioid analgesic derived from benzomorphan. It is used for the relief of moderate to severe pain, including labor pain. Oral, intramuscular, intravenous and subcutaneous administration.

A fecha de última actualización no encontramos datos publicados sobre su excreción en leche materna.

Its pharmacokinetic data (low molecular weight and moderate protein binding) makes transfer to breast milk possible, but its very high volume of distribution makes it difficult.

Its very low oral bioavailability (Sanofi 2018) minimizes the passage into plasma of the infant from ingested breast milk, except in the premature and in the immediate neonatal period in which there may be greater intestinal permeability.

It may increase prolactin levels. (Manner 1987)

Until more published data is known about this drug in relation to breastfeeding, known safer alternatives are preferable (Sachs 2013), especially during the neonatal period and in the event of prematurity.


  • Butorphanol Tartrate (Safe substance and/or breastfeeding is the best option.)
  • Ibuprofen (Safe substance and/or breastfeeding is the best option.)
  • Morphine (Fairly safe. Mild or unlikely adverse effects. Compatible under certain circumstances. Follow-up recommended. Read Commentary.)
  • Paracetamol (Safe substance and/or breastfeeding is the best option.)

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

Pentazocine is also known as

Pentazocine in other languages or writings:


Pentazocine belongs to this group or family:


Main tradenames from several countries containing Pentazocine in its composition:


Variable Value Unit
Oral Bioavail. 20 %
Molecular weight 285 daltons
Protein Binding 60 %
VD 4.4 - 7.8 l/Kg
pKa 10.4 -
Tmax 1 - 3 hours
2 - 3 hours


  1. Sanofi. Pentazocine. Drug Summary. 2018 Full text (in our servers)
  2. Sachs HC; Committee On Drugs. The transfer of drugs and therapeutics into human breast milk: an update on selected topics. Pediatrics. 2013 Sep;132(3):e796-809. Abstract Full text (link to original source) Full text (in our servers)
  3. Manner T, Kanto J, Scheinin H, Viinamäki O, Scheinin M. Meptazinol and pentazocine: effects on prolactin, growth hormone and vasopressin levels in plasma. Pharmacol Toxicol. 1987 Nov;61(5):301-4. Abstract

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