Yoon Hang Kim, MD, MPH   ·   www.directintegrativecare.com

Low-dose naltrexone (LDN), typically dosed between 0.5 and 4.5 mg at bedtime, has become a widely used off-label therapy for autoimmune disease, chronic pain, and complex chronic illness. One of the questions I am asked most often in my integrative medicine practice—and inside the LDN Support Group community—is whether LDN is safe for patients with kidney disease. The short answer is: usually yes in mild chronic kidney disease (CKD), with caution as kidney function declines, and only with specialist input in end-stage renal disease (ESRD) or dialysis.

This article walks through the pharmacology, the available evidence, and a practical CKD-stage-specific framework that clinicians can use when considering LDN in patients with renal impairment.

Why Kidney Function Matters for Naltrexone

Naltrexone is extensively metabolized by the liver via aldo-keto reductase enzymes to its primary active metabolite, 6-β-naltrexol. Although first-pass metabolism is significant, the parent drug and its metabolites are then eliminated largely through the kidneys. According to FDA prescribing information, between roughly 53% and 79% of an oral dose is excreted by the kidney, while less than 2% appears in the urine as unchanged naltrexone and fecal excretion is a minor route. The mean half-life of naltrexone is about 4 hours, and 6-β-naltrexol is approximately 13 hours.

Because both the parent drug and its primary metabolite depend on renal clearance, the FDA label explicitly states that caution is recommended when administering naltrexone to patients with renal impairment. That statement applies to standard 50 mg dosing, but it is the pharmacologic starting point for any discussion of LDN in CKD.

What the Evidence Actually Shows

Mild to moderate CKD

Formal dose-adjustment guidelines for naltrexone in CKD are lacking. A recent clinical review of addiction pharmacotherapy in renal impairment noted that naltrexone—unlike acamprosate or gabapentin—has no formal renal adjustment guidance, but caution is warranted across all stages of CKD. In practical terms, most integrative clinicians and LDN-experienced prescribers treat mild CKD (eGFR roughly 60–89 mL/min/1.73 m²) as a setting where standard low doses of LDN can generally be used with monitoring, given that LDN doses are a fraction (roughly one-tenth) of the FDA-approved 50 mg dose.

Patient-facing guidance from LDN experts

The LDN Research Trust, a UK-based charity whose clinical faculty includes several of the longest-practicing LDN prescribers, has addressed this question directly. Their position is that, in the vast majority of cases, patients with chronic kidney disease who are not on dialysis can take LDN safely, and that the small amount excreted by the kidneys is unlikely to harm renal function. They distinguish end-stage renal disease and dialysis as a separate scenario that warrants a more careful conversation.

LDN Research Trust clinicians have also pointed out that LDN may be particularly relevant when the kidney disease has an inflammatory or autoimmune component, because the kidneys are responsive to immunomodulation—though LDN is generally expected to be less useful when kidney disease is secondary to cardiovascular causes.

End-stage renal disease and hemodialysis

The most informative pharmacokinetic data in advanced renal failure come from a study of standard-dose naltrexone (not LDN) in seven hemodialysis patients with uremic pruritus. The investigators found that peak plasma concentrations of naltrexone were substantially higher in dialysis patients than in healthy subjects, which they attributed to decreased hepatic first-pass metabolism associated with ESRD and to impaired renal elimination. Despite this, hemodialysis itself removed only about 1.27 mg of drug per session, with a dialyzer extraction ratio near 30%. The authors concluded that hemodialysis has little effect on naltrexone blood levels and that dosage adjustment is not required based on the dialysis procedure itself in patients with advanced dialysis-dependent renal failure.

The important clinical nuance is that the same study documented notably elevated plasma levels overall in ESRD—meaning dialysis does not rescue patients from accumulation, even if the dialysis session itself removes little drug. That is why clinical caution in ESRD is appropriate even though the data technically show that naltrexone can be used in this population.

A signal of benefit in ESRD

There is a small but growing body of literature using low-dose naltrexone specifically for uremic pruritus in dialysis patients. A 2025 case report and literature review described a dialysis patient with intractable uremic pruritus refractory to topicals, antihistamines, and gabapentinoids who experienced symptomatic improvement within three days of starting 5 mg of naltrexone daily, with side effects that were tolerable. The authors emphasized that well-controlled studies are still needed, but the case supports a potential role for LDN in this difficult symptom, particularly where difelikefalin is unavailable.

A CKD-Stage-Specific Framework

The table below summarizes a practical approach I use in my own clinical decision-making. It is not a rigid protocol—every patient requires individual assessment—but it offers a starting point.

Practical Clinical Pearls

• Start low, go slow. In any patient with reduced eGFR, I lean toward starting at 0.5–1.5 mg and increasing in small increments only if tolerated. The LDN dose range is already well below the FDA-approved 50 mg, which provides a meaningful margin of safety in most mild-to-moderate CKD.
• Review the full medication list. Any patient on an opioid—even tramadol, even as-needed—should not start LDN until opioids have been stopped and cleared. This is non-negotiable regardless of kidney function.
• Do not forget the liver. Naltrexone AUC rises roughly 5- to 10-fold in compensated and decompensated cirrhosis, respectively. CKD patients with concurrent liver disease require a more conservative approach than CKD alone.
• Coordinate, do not freelance. In advanced CKD, ESRD, or dialysis, the conversation should involve nephrology. LDN may still be appropriate—especially for symptoms like uremic pruritus—but the decision should be made jointly.
• Monitor, then monitor again. Check baseline eGFR and liver enzymes, and recheck at regular intervals. Ask specifically about sleep changes, vivid dreams, GI upset, and any new neurologic symptoms, which may appear earlier or more intensely in patients with reduced clearance.

Bottom Line

LDN is generally acceptable in mild CKD, calls for caution as kidney function declines, and should not be started casually in ESRD or dialysis without specialist input. The pharmacokinetic data tell us that standard-dose naltrexone produces higher plasma concentrations in ESRD and that hemodialysis does not meaningfully remove the drug—but also that a dose adjustment strictly based on the dialysis procedure is not required. Put plainly: the drug can often be used, but it demands respect for the kidneys, respect for the liver, and a prescriber who is paying attention.

If you are a patient with kidney disease considering LDN, bring this article to your physician and, if you have one, your nephrologist. If you are a clinician and would like to discuss a specific case, I welcome inquiries through Direct Integrative Care.

About Dr. Kim

Dr. Yoon Hang "John" Kim is a board-certified integrative medicine physician with over 20 years of clinical experience. He completed his integrative medicine fellowship at the University of Arizona under Dr. Andrew Weil and holds certifications in preventive medicine, medical acupuncture, and integrative/holistic medicine. Through his telemedicine practice, Dr. Kim specializes in utilizing LDN or Low Dose Naltrexone for treating autoimmune conditions, chronic pain, integrative oncology, and complex conditions including fibromyalgia, chronic fatigue, MCAS, and mold toxicity. He is the author of three books and more than 20 articles, and has helped establish integrative medicine programs at institutions nationwide.

Professional: www.yoonhangkim.com | Clinical: www.directintegrativecare.com

References

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7. LDN Research Trust. Can Low Dose Naltrexone (LDN) be taken by someone with chronic kidney disease? Available at: https://ldnresearchtrust.org/can-low-dose-naltrexone-ldn-be-taken-someone-chronic-kidney-disease

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