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Rational Polypharmacy

Naltrexone is a remarkable drug for intractable pain

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I first saw this RN in June 2006.

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She is now 60 years old.  She was an OR scrub nurse for almost 30 years, but was disabled for the last 5 years before seeing me. She had Reflex Sympathetic Dystrophy [RSD] of both legs with “arthritis” of the feet/ankle that felt like she was “90 years old” with cold allodynia. Allodynia is pain from a stimulus such as light touch or a breath or air that is not normally painful. Imagine a light touch that feels like severe nerve pain, one of the most disturbing pains a person could have. The temperature of her feet was 81 degrees, hands 92 degrees.

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Pain of both feet felt like a vise grip, gnawing, penetrating, “like broken bones in the feet,” variable at different times but always worse as the day progressed, with a crushing sensation that penetrated through foot and ankle. She was unable to tolerate socks or anything on her feet after 5 pm, unable even to tolerate air on the area, unable to tolerate coolness below waist, but felt hot above waist. She wore a blanket and covers on the hottest 120 degree days, and forced herself to tolerate touch at the legs in order to desensitize them, as we instruct patients to do. She felt constant tingling numbness of the soles of feet for 3 years, with weakness, stiffness “almost solid” like a block. Spasm in soles of feet had resolved the last 6 months before seeing me.

Pain ranged from 2 to 9 on a scale of 10, where 10 is the worst pain imaginable, worst after 5 pm. Average pain was 3. It interfered with sleep at times, and she used a tented frame to keep blankets off her feet, preheated the bed to avoid any coolness, and avoided cold under all circumstances. In the morning, the joints felt like she had a broken ankle. She would massage the feet with lotion, put on alpaca socks, and slowly begin to walk. Then tried to mobilize the joints. Walking made pain worse though walking had always been a favorite activity.~

Before seeing me she had had more than 10 sympathetic blocks, was hospitalized 11 days due to headache from prednisone 60 mg that had been trialed to relieve her pain. She had been prescribed Procardia to relieve the “vascular” disease that she did not have but the drug led to gangrene of the gall bladder; she had been prescribed almost every “adjuvant” used to relieve pain and as much as 9 grams of Neurontin daily, all of this to attempt to relieve the severe pain in her legs and feet.

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This is how she got better

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When I first saw her in 2006, I prescribed low dose oral ketamine that gave relief lasting up to 3 hours from each dose. She then requested referral to Dr. Schwartzman, chief of neurology at Drexel University in Philadelphia, for continuous 5 day ketamine infusion that was done May 2007. She was pain free but it completely lost effect after 8 months, despite booster infusions every 4 to 6 weeks for 4 hours daily over 2 days during those 8 months. After insurance the cost out of pocket was $45,000 in 2007 alone. Dr. Schwartzman had nothing more to offer after it failed and said most patients have relief for less than 6 months if at all.

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In March 2007, I started her on a combination of Namenda 55 mg daily with lamotrigine 350 mg daily that relieved 90% of the pain, but once every 6 to 8 weeks she needed 12.5 to 25 mg low dose oral ketamine for breakthrough pain. Even more rarely, she used oxycodone 10 to 20 mg.

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In October 2008, adding naltrexone 1 mg by mouth, she became pain free. Since then she has not needed anything for breakthrough pain and on 3/5/09, she reported that her last use of ketamine and oxycodone occurred with the addition of low dose naltrexone.

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In 2009, she hiked 30 miles down the Grand Canyon and back up in 3 days.

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Naltrexone was later increased to 4.5 mg as she completely tapered off lamotrigine.

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By December 2009, the RSD was 98% better and she reported that it was not pain anymore. Medications then were naltrexone 12.5 mg at bedtime and Namenda 55 mg daily in divided doses. She had just a “remnant” of a little buzz, but no crushing except when active, late in the day.

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A few months later she slowly tapered off Namenda with no increase in pain; and in October 2010, on my advice she tapered naltrexone 12.5 mg from daily to every third day. There has been no increase in pain but she is reluctant to discontinue naltrexone for fear that RSD may recur.

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She hikes 2 miles 3 to 4 times a week, does Iron Mountain once a week, does “Silver Sneekers” exercise 1 hour 3 times a week and sleeps well 8 to 10 hours a night without a sleeping pill.

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She remains on low dose naltrexone as her sole medication for this

previously disabling neuropathic pain syndrome~

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She has returned to part time work and spends a few weeks a month traveling the world, hiking, volunteering, sightseeing.

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Research funding is needed to view whether we can detect

activated glia in the spinal cord, as discussed here.

If there are no signs of activated glia, she may feel reassured that the condition has resolved.

Naltrexone is an immune modulator.

The site of action of naltrexone is at the Toll-like receptor (TLR4) attached to the cell surface membrane of glia.

The ability to view activated glia would help greatly in treatment of so many conditions including neuropathic pain.

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Naltrexone

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I have found that naltrexone is a remarkable medication for various pain conditions, and going through the steps of rational polypharmacy may be very rewarding for some patients though at times it may work all on its own. It has caused me to completely reassess how I approach the treatment of intractable pain – not just RSD or CRPS but arthritis, sciatica and various forms of mechanical pain. And it has led to further changes in the timing and dosing of naltrexone based upon the experiences patients have reported back to me over the years. It is hoped that further research will lead to better understanding of how naltrexone acts upon pain pathways. Surprisingly we already know quite a fair amount.

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My deepest gratitude to Dr. Jau-Shyong Hong, Chief of Neuropharmacology at NIH, whose many generous discussions, emails and research publications have helped me to understand it’s profound anti-inflammatory effect in the central nervous system through its actions on microglia. I previously posted a discussion of mechanisms of naltrexone and dextromethorphan in greater detail here. Naltrexone and dextromethorphan are classified as morphinans, morphine-like. They suppress Superoxide, a free radical that destroys neurons which may cause or contribute to Alzheimers and Parkinsons Disease. That research goes back to the late 1980′s and continues to grow. Phase II studies with morphinans are now being done on those conditions. Studies are also going on now with naltrexone/Wellbutrin combination for weight loss. The drug is called Contrave, from Orexigen Therapeutics Inc. and the dose I believe is 32 mg naltrexone – I do not know how they decided upon that dosage.

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In my experience, naltrexone is a very benign drug at these low doses, though colleagues who prescribe 400 mg for the FDA approved use at that high dose may see some liver toxicity. I always begin at 1 mg or 4.5 mg, depending upon whether or not the patient is a slow drug metabolizer, i.e. may lack one of the CYP P450 chromosomes for metabolizing drugs. I have long suspected it also has an effect on the hypothalamus because a few patients with profound postmenopausal hot flashes have reported that is no longer a problem and that their husbands simply cannot believe the bonus, and this may explain the effect upon appetite that Orexigen has found. At higher doses than I generally use there may be some constipation which is treatable. It may cause vivid dreaming in some, and a small percentage may have insomnia for a few days. Pharmacology and safety is discussed here.

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Stay tuned. I’ll be adding more case reports of different pain conditions in the near future. They are truly fascinating. It has changed my entire approach to treating pain.

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Cost

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Wouldn’t it be nice if NIH funded more for pain research? Imagine how much money that would save the country and save the lives of each person with disability who could recover? As I posted here, the American Pain Society has shown that NIH spends 0.67% of its budget on pain research – less than 1% – though 10 to 20% of the population in the US suffers from chronic pain, an estimated 60 million Americans, and pain conditions are more prevalent among the elderly.

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I am told by my pharmacist that perhaps 70% of the time insurance will approve coverage for compounded low dose naltrexone. It is very affordable but some insurance carriers deny payment for naltrexone. Medicare will not pay for compounded medication either. Compare this low cost compound to the wholesale price for 100 tablets of Oxycontin, $1300, which may not be relieving pain – then multiple that by 2 or 3 each month for one patient. Imagine if the $22 billion of federal money for health insurance technology, for software which is untested and will expire in a few years, instead went into NIH funding for pain research. What a lovely thought. 

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The material on this site is for informational purposes only, and

is not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider.

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For My Home Page, click here:  Welcome to my Weblog on Pain Management!

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