Low-Dose Naltrexone for Chronic Pain Management

Definition and Mechanism

Low-dose naltrexone refers specifically to naltrexone used at 1-5 mg daily, which is approximately 1/10th of the standard 50 mg dose used for opioid and alcohol dependence, as stated by the Praxis Medical Insights guideline society 1

Patients requiring opioid therapy for pain management should not be prescribed low-dose naltrexone, as it will block opioid analgesia even at low doses, according to the Praxis Medical Insights guideline society 1
Patients currently taking opioids must be opioid-free for a minimum of 7-10 days before initiating any dose of naltrexone, as recommended by the Praxis Medical Insights guideline society 1
Patients with acute hepatitis or decompensated cirrhosis should avoid low-dose naltrexone, although this applies more to standard dosing, as noted by the Praxis Medical Insights guideline society 1
Hold low-dose naltrexone for 2-3 days before elective procedures if opioids will be needed for pain control, as advised by the Praxis Medical Insights guideline society 1

The FDA-approved dose for alcohol use disorder is 50 mg once daily, and for opioid dependence, initiate with 25 mg test dose, then 50 mg daily if no withdrawal occurs, with an alternative supervised dosing schedule of 100 mg on Monday and Wednesday, and 150 mg on Friday, as stated by the Praxis Medical Insights guideline society 1
The naltrexone-bupropion combination, each tablet containing 8 mg naltrexone + 90 mg bupropion, is used for obesity, not chronic pain, and should not be confused with low-dose naltrexone protocols, with a titration schedule of 1 tablet daily morning, increasing to 2 tablets twice daily, as described in Gastroenterology 2, 3