OxycodoneOpioids are amazingly effective for pain control. Patients on chronic opioids, however, often struggle with constipation. These patients may fail supportive treatment with enemas and laxatives.

Trick of the Trade

Oral naloxone

Interestingly, there are minimal systemic effects with oral naloxone. So, constipation can be directly targeted without causing systemic opioid withdrawal. Published case series reports show a variable range of therapeutic doses, ranging from 0.1-20 mg of oral naloxone. One series quoted no effectiveness under 1.5 mg. Generally 2 mg PO is a good starting point. Then titrate up slowly to achieve the laxative effect to minimize any systemic absorption.

FYI, you need to use the IV preparation, because no PO formulation exists.

Alternatively per Bryan Hayes (@PharmERToxGuy), you can also use methylnaltrexone, which also is a mu-receptor antagonist. It is dosed 8-12 mg (0.15 mg/kg) subcutaneously.

Thanks to Dr. Graham Walker (Kaiser San Francisco) and Sarah Burkart (PA at Univ of Cincinnati) for sharing this great tip!

Holzer P. Non-analgesic effects of opioids: Management of opioid-induced constipation by peripheral opioid receptor antagonists: prevention or withdrawal? Curr Pharm Des. 2012 Jun 28. [Epub ahead of print] Pubmed

Leppert W. The role of opioid receptor antagonists in the treatment of opioid-induced constipation: a review. Adv Ther. 2010 Oct;27(10):714-30. Pubmed .

Meissner W, Schmidt U, Hartmann M, Kath R, Reinhart K. Oral naloxone reverses opioid-associated constipation. Pain. 2000 Jan;84(1):105-9. Pubmed .


Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at https://t.co/50EapJORCa Bio: https://t.co/7v7cgJqNEn
Michelle Lin, MD