Protocol for Low-Dose Naltrexone for Cancer

Michael B. Schachter, M.D., CNS, F.A.C.A.M.  

Dr. Bernard Bihari of New York City has been using low doses of naltrexone (an opioid-narcotic antagonist) to stimulate immune function in AIDS patients for many years.  In 1985, he administered this treatment to an AIDS patient suffering from non-Hodgkin’s lymphoma and was surprised to find that the patient achieved a complete remission.  Subsequently, Dr. Bihari followed up on this initial finding and found that a low dose of naltrexone can have a dramatic positive effect on certain other cancers as well.

The treatment probably should be continued for a lifetime, as some patients who obtained complete remission on the treatment, had a recurrence after stopping the naltrexone. Some of these patients were able to obtain a second remission when the medication was restarted.

The treatment seems to work by causing the body to secrete endorphins (metenkephalin and beta-endorphin), which attach to cancers having opiate receptors, shrinking the tumors and inhibiting their growth. Low dose naltrexone may also help cancer patients by up regulating opioid receptors in cancer cells.  When metenkephalin and/or beta-endorphins, are attached to cancer cells while they are dividing, it seems to stimulate a process of programmed cell death or apoptosis, thus killing some cancer cells.  Low dose naltrexone may also work by so stimulating certain immune system cells that tend to kill cancer cells, including T4 and natural killer cells.

Responses have been seen in cancer patients with a wide variety of cancers.  These include: colon cancer, non-Hodgkin’s lymphoma, Hodgkin’s Disease, chronic lymphocytic leukemia, prostate cancer, malignant melanoma, multiple myeloma, neuroblastoma, pancreatic cancer, breast cancer, ovarian cancer, uterine cancer, brain cancer, lung cancer and others.

The protocol is 1.5 to 4.5 mg at bedtime.  It must not be a timed-release preparation and should be given at bedtime.  Up until recently, Dr. Bihari had routinely used 3 mg, reducing it down to as low as 1.5 mg in the rare patient who experienced a mild sleep disturbance.  (Many patients report improved sleeping.)  However, recently, he has noted that some patients who did not respond to 3 mg. did respond to 4.5 mg. and has begun to use this dose more frequently.  No more than 4.5 mg. must be used.  Occasionally, lower doses are necessary.  At doses up to 4.5 mg. per day, naltrexone is immune enhancing.  At 5 mg. or more daily, it is immune suppressing. The usual, commercial oral preparation of naltrexone is 50 mg; so, the 1.5 to 4.5 mg dose must be made up by a compounding pharmacy.  A month’s supply should run about $30.  Although there are no known significant side effects to the treatment, in about 1 out of 50 patients, the patient will experience a sleep disturbance.  In this case, Dr. Bihari recommends that the pharmacy make up a 100-ml. solution containing naltrexone in distilled water at a concentration of 1 mg/ml.  The patient is told to take 1 to 1 ½ ml. at bedtime—possibly working up to 2 ml. or 2 mg.

According to Bihari, a significant minority of cancer patients obtain a positive response to the treatment.  A summary of his results, as well as additional information may be found on his website at http://lowdosenaltrexone.org.  He reports improvement as early as within a month and remission frequently occurs within 6 months.  Some of his patients have been on the program for more than seven years.

He has recently found that the treatment does not seem to work in prostate cancer patients who have received or are receiving some form of hormone manipulation treatment prior to starting the low dose naltrexone.  This includes patients who have received Lupron, Casodex, Eulexin, DES, or other drugs designed to reduce testosterone.  In addition, patients who have been treated with PC Spes, the herbal preparation with estrogenic effects, do not seem to respond.  I believe this finding may have implications for women who have been treated with hormonal manipulation for breast cancer with drugs such as tamoxifen, aromatase inhibitors, or synthetic progestins, such as Megace.  More research is needed to determine if this general principle holds up and if so, the reasons for it.  On the other hand, the treatment does seem to work in some patients who have received other forms of conventional treatment, such as radiation and/or chemotherapy.  I do not know of any other complementary or alternative cancer (CAM) treatment that interferes with the treatment, although this is a possibility.  My guess is that most CAM treatments will turn out to be synergistic with low dose naltrexone.

One contraindication to the use of low dose naltrexone is if the patient is receiving opioid narcotics for pain (painkillers, such as codeine, morphine, Demerol or the Duragesic patch).  In such a case, the effect of low dose naltrexone is lost and it may interfere with the pain reducing effects of the opioid narcotic.  Also, a patient on opioids may experience withdrawal symptoms if he starts the naltrexone treatment.  A patient on opioids must be taken off these drugs by tapering them down, prior to beginning low dose naltrexone.  Dr. Bihari uses as a substitute one of the anti-inflammatory drugs Celebrex* (up to 200 mg. BID) or Vioxx* (25 mg. twice daily) and possibly, if necessary, Neurontin* (300 mg. TID).  These drugs may be taken daily until the pain is hopefully relieved by the naltrexone.  Although, the likelihood of GI bleeding is less with these new COX 2 inhibitors (Celebrex* & Vioxx*), patients should be monitored for possible GI bleeding while taking these drugs.

Obviously, Dr. Bihari’s work needs to be confirmed.  However, since it is such a safe and inexpensive treatment, I think any patient who has one of the cancers that have previously responded, should be considered for a trial of low-dose naltrexone.  It may also be somewhat helpful for patients whose cancers do not contain opiate receptors because of its immune enhancing effects.

One compounding pharmacy that frequently compounds the low-dose naltrexone is Bigelow’s in New York City (414 6th Avenue--between 8th and 9th Streets:  Phone Number:  212-533-2700).  A second pharmacy that may be used is Hopewell Pharmacy and Compounding Center (1 West Broad Street, Hopewell, New Jersey 08524, Phone number:  1-800-792-6670; FAX:  1-609-466-8222).

December 6, 2001