Low Dose Naltrexone

Description

Naltrexone is typically used to treat opioid use disorder and alcohol abuse disorder. It is classified as an opioid antagonist blocking the effects of exogenously administered opioids. However, at low doses (0.5mg–6mg), oral naltrexone has been prescribed for its possible analgesia and anti-inflammatory effects, which have not been observed at higher doses. Low dose naltrexone may be beneficial for the treatment of various conditions including chronic pain and autoimmune illnesses.

Pronunciation

nal trek sown

Brand Names

Vivitrol, ReVia, APO-Naltrexone

Drug Class

Antidote, Opioid Antagonist

🔬 Mechanism of Action

As a pure opioid antagonist, naltrexone competes with opioid receptors and can displace opioid drugs from the receptors. Naltrexone antagonizes the effects of opioids with long-lasting effects. At low doses, this transient receptor blockade is believed to trigger an upregulation of endogenous opioid production, resulting in anti-inflammatory and analgesic effects.

📊 Administration & Dosing

– May be taken by mouth with or without food. Taking with food may minimize gastrointestinal side effects.

– LDN doses typically range from 0.5mg to 6mg daily — contact your healthcare provider for specific dosing instructions.

– To minimize risk of withdrawal, patients should be opioid-free for at least 7–10 days before starting.

⚠️ Drug Interactions

– Opioids: Do not take together — may precipitate opioid withdrawal and reduce opioid effectiveness.

– Bremelanotide: Do not take together — may result in naltrexone treatment failure.

– Opioid antagonists (Naldemedine, Naloxegol): May increase risk of opioid withdrawal.

🚨 Adverse Effects

Common side effects:

• Nausea / vomiting

• Gastrointestinal pain / cramps

• Joint or muscle pain

• Difficulty sleeping

• Anxiety

• Headaches

Tell your doctor immediately if you experience: yellowing of the skin (jaundice), suicidal thoughts, symptoms of opioid withdrawal, or mild symptoms that do not go away.

🤰 Pregnancy, Breastfeeding & Pediatrics

– Pregnancy: Testing is recommended prior to initiation. Naltrexone and its metabolite (6-beta-naltrexol) cross the placenta. Limited data exists — speak to your doctor about risks and benefits.

– Breastfeeding: Naltrexone and 6-beta-naltrexol are present in breast milk. Discuss risk and benefits with your doctor.

– Pediatrics: Safety and effectiveness have not been established in pediatric patients.

📚 References

– Naltrexone [monograph]. In: Lexicomp Online [online database]. Hudson, OH: Lexicomp (accessed 2020 June 11).

– Naltrexone [monograph]. In: Micromedex [online database]. Greenwood Village, CO: Truven Health Analytics (accessed 2020 June 11).

– Younger J, Parkitny L, McLain D. The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain. Clinical Rheumatology. 2014;33(4):451–459. doi:10.1007/s10067-014-2517-2

– Toljan K, Vrooman B. Low-Dose Naltrexone (LDN) — Review of Therapeutic Utilization. Medical Sciences (Basel). 2018;6(4):82. doi:10.3390/medsci6040082