Drugs & Clinical Trials

Topical Morphine – An Experimental Approach to Chronic Pain

February 22, 2009 | By Sajid Surve, DO | Share / Save / Email / Bookmark | 8 Comments

Drugs and Clinical Trials Category Practitioners who treat patients with chronic pain understand just how difficult management of that population can be. As of today, the evaluation of pain remains completely subjective; no lab tests or imaging studies can provide any meaningful insight into how much pain a patient feels. When the pain is severe and intractable, the only option becomes opioid analgesics, which have high potential for abuse and are laden with side effects ranging from constipation and sedation to respiratory depression, testosterone deficiency, and immuno-modulation. The trouble with opioids is that they must be ingested in an oral form with systemic absorption regardless of where the actual pain lies. Over the past few years, a quiet murmur has been rippling through the pain practitioner community about the possibility of dispensing morphine as a topical agent. Small scale clinical trials and animal models have shown some promise, and also raised some questions about this experimental approach.

Poppy Field Converting systemic agents to topical agents is not a new phenomenon. A few topical agents already exist for the treatment of pain. For example, aspirin-type products exist in topical form as a cream which is available over the counter. Similarly, topical capsaicin cream and gel is commercially available for the treatment of pain. In the prescription category, there has been recent approval of topical lidocaine (same as the novocaine used for dental anesthesia) for the use of chronic pain associated with diabetic peripheral neuropathy and post-herpetic neuralgia (also known as shingles). More recently, there has been FDA approval for topical diclofenac, an anti-inflammatory similar to ibuprofen, as both a patch and a gel for acute musculo-skeletal conditions and pain associated with arthritis.

In a recent issue of Practical Pain Management, a journal for pain practitioners, Dr. Forest Tennant detailed his practice-based clinical trial on a homemade formulation of topical morphine for patients who had failed all other management. The physician simply crushed up immediate-release morphine tablets and mixed it into a moisturizing cold cream which the patient supplied. The patients were instructed to apply the cream to painful areas as needed. For his observation study, he noted that almost all patients noted significant relief of their pain symptoms, which lasted for hours. Their side effects were negligible. It’s important to bear in mind that these are patients who had severe pain which failed to respond to any other conventional treatment. Results of this magnitude are profound in such a refractory population.

Not all the reviews have been positive, however. Some animal models have shown that topical morphine used on painful skin ulcers are associated with delayed wound healing. Also, while topical diclofenac shows 1-6% systemic absorption of medication depending on preparation, there are no convincing studies as of yet to measure how much topical morphine makes its way into the bloodstream. If that number is too high, then patients run the risk of all the adverse effects associated with opioids. Regardless, for patients with intractable pain limited to small areas, topical morphine holds promise as a useful agent when all else has failed.

References

Tennant, F. Topical Use of Morphine. Practical Pain Management. October 2008.

Rook JM, Hasan W, McCarson KE (2008). Temporal effects of topical morphine application on cutaneous wound healing. Anesthesiology, 109 (1), 130-136.

Tags: diclofenac, ibuprofen, lidocaine, medication, morphine, opioid, pain

8 Comments/Trackbacks

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Katkinkate
February 22, 2009 | Permalink

I understood that opioids acted on the pain receptors in the brain to kill pain. Am I wrong, or have they just recently discovered they work locally as well?

Art
February 23, 2009 | Permalink

Add a bit of DMSO to the morphine mix and it will penetrate deeper and faster. DMSO is a very good carrier agent. Down side is the patients breath will smell like garlic and the DMSO has a smell that reminds me of ‘fish tank water’.

Prof/Dr Brian Rothbart
February 25, 2009 | Permalink

Thanks for your post about this very important issue of treatments for chronic pain – a problem of pandemic proportions.

Unfortunately, often drugs and means of pain management are the only options offered to chronic pain sufferers. And now with reports of addiction and abuse being rampant in people suffering from pain, it is clear that we need new, permanent and drug free solutions.

Having discovered a previously unknown source of chronic musculoskeletal pain after almost 40 years of research and clinical practice, I have developed a therapy that permanently eliminates chronic muscle and joint pain without the use of drugs or surgery.

My new book, Forever Free From Chronic Pain discusses not only my discoveries and innovative therapy, but my own experience with chronic pain as well.

The book also discusses why current treatments for chronic neck, hip, knee and back pain aren’t working, how to determine if my innovative therapy will work for a chronic pain sufferer and how, through advanced technology, a person’s body can heal itself for good.

I invite you to sign up for a free chapter and learn more about my book at: http://www.foreverfreefromchronicpain.com.

For those interested in speaking out against the lack of real options for pain sufferers, I invite you to join the group, Citizens for a World Free From Chronic Pain: http://tinyurl.com/CWFCPgroup

Thank you for helping to bring awareness to this chronic pain epidemic and the need for real solutions.

Best wishes,
Prof/Dr Brian A Rothbart

Mary Scott RPh,CGP
February 26, 2009 | Permalink

You neglected to mention a topical opioid, fentanyl (Duragesic), which is used extensively in pain management. It is available in transdermal patch and buccal lozenge.While it has some systemic side-effects like oral opioids, it has been a real godsend for patients with chronic pain. I have been a consultant to various hospice organizations and for patients on multiple oral meds, it really cuts down on the amount of pills they have to swallow per day. Also, it tends to cause more side-effects in those with less muscle stores (use cautiously in 80lb elderly)
The topical morphine idea sounds crazy if you ask me-could it be the placebo effect at work?
Mary Scott, RPh, CGP (Certified Geriatric Pharmacist)

Sajid Surve, DO
February 26, 2009 | Permalink

Mary,

There is a distinct difference between the fentanyl patch and other agents such as the lidocaine and diclofenac patches. Fentanyl is a transdermal agent, while the others are topical agents. Transdermal means it is absorbed through the skin and taken into the bloodstream to work at a site remote from the application site. This is why one can place a fentanyl patch on the chest for low back pain. Topical agents are only meant to act directly under their application site, and have minimal systemic absorption.

As for topical morphine, I think its has a possibility to work. If you recall, opioids work by suppressing the release of acetylcholine through binding at the presynaptic mu receptors (peripherally), as well as postsynaptic inhibition of descending efferent pathways (centrally). If this formulation can suppress neuronal activity at the surface nociceptors, then I believe the patients would receive some benefits.

Jason Victor
March 01, 2009 | Permalink

Any news on there being larger double-blinded clinical trials for this? It would be interesting to see if there is a placebo effect. It’s probably not if no other treatment worked for this population, but still …

Irug
August 05, 2009 | Permalink

Living in pain is one of the worst feelings a man or woman can have. I think any experimental approaches on any type of pain killer is a wonderful idea. If the industry took further steps for aiding those with chronic pain i truly feel we could be in a better place in the future. The placebo affect may interfere, but as Jason stated, it is quite unlikely.