Prialt now FDA approved specifically for neuropathic pain
Broadly speaking, there are two types of pain. There is nociceptive pain, which is caused by tissue injury or inflammation. This pain tends to be temporary, lessening as the tissues heal. The second type of pain is far more difficult to manage and is called neuropathic pain. This pain is caused by trauma to the nervous system that directly injures nerves or interferes with the ability of nerves to process pain signals.
For patients with neuropathic pain, oral medications are often unsatisfactory. The typical patient with severe neuropathic pain has failed trials of physical therapy, TENS units, anti seizure medications (neurotin, lyrica, topamax, lamictal), anti depressant medications (Elavil, pamelor, cymbalta, effexor), and eventually may be placed on narcotics.
Neuropathic pain often does not respond well to oral narcotics, resulting in some patients being placed on escalating doses.
The most concerning aspects of high dose narcotics are side effects (which increase with the dose), tolerance (loss of effect with time requiring increasing doses), hyperalgesia (escalating doses paradoxically increasing pain), physical dependence (withdrawal if narcotics are suddenly stopped) and, rarely, addiction (uncontrolled use and craving).
Naturally Occuring Venom
Prialt (or Zoconitide) is a non-narcotic synthetic form of a naturally occurring venom (neurotoxin) found in the Conus Magus snail. The snail’s venom was known since antiquity as a topical remedy for burns, abscesses and other wounds.
Cone snails are hunting animals, which use neurotoxins to paralyze their prey. The snails use their harpoon like limb to grab, inject, and then consume the fish after it is paralyzed. Prialt is now FDA approved specifically for neuropathic pain.
If taken by mouth prialt would be rapidly and completely destroyed by our digestive enzymes. Therefore, Prialt is only delivered by the Medtronic pain pump directly into the spinal canal fluid.
In the spinal fluid the Prialt molecules block pores on pain sensing nerve cells, which stops the flow of calcium into the cells. This reduction of calcium flow prevents the nerve cells from sending signals to the brain, reducing the perception of pain (see figure 2). When used in the pain pump, Prialt can often reduce neuropathic pain allowing the patient to significantly reduce or wean off narcotics.
The pain management physician determines that a patient is a good candidate for Prialt by administering a test dose in which a small amount of Prialt is injected into the spine under x-ray guidance.
The patient is then observed closely and pain levels are recorded for the next several hours. Then the patient is asked to perform specific exercises to determine the drug’s effect on the pain. If greater than 70-80 percent of the pain is reduced, the trial of Prialt is considered successful.
After the successful test dose with Prialt, the patient may be scheduled for implantation of a Medtronic intrathecal pump.
The pump implantation is a minor outpatient surgical procedure, which provides the patient with a constant infusion of the pain relieving Prialt. After implantation, the pump is programmed to deliver slowly increasing amounts of Prialt to minimize drug side effects.
As the Prialt dose increases and pain is reduced, narcotics are simultaneously weaned.
If you have a severe pain condition that has failed all other standard conservative therapies, consider undergoing evaluation by a pain management specialist to determine if this mode of direct intrathecal medication therapy is appropriate for you.
INTERESTING FACTS ABOUT CONE SNAIL
Less than one percent of the more than 500 species of cone snails have been studied. Each snail produces multiple neurotoxins in its venom. Some scientists feel the cone snails hold more promise for new medicines than any other species in nature.
Different snail toxins in preclinical trials already hold promise for new treatments for pain, Parkinson’s Disease, and depression. The snails are found in the warm tropical coral reefs.
Unfortunately the coral reefs are being destroyed; over 26 percent of the reefs are damaged beyond repair and between 30 to 50 percent are severely degraded. If the reefs are lost, we also lose the potential cure for many diseases.
ABOUT THE AUTHOR
Dr. Richard Gayles is a graduate of the University of Michigan Medical School. After obtaining his medical degree, Dr Gayles completed a residency in anesthesiology at The Johns Hopkins Hospital in Baltimore, Maryland. Subsequently, he held the post of visiting registrar at St. Bartholomew’s Hospital in London. Upon his return to the United States, Dr. Gayles completed a fellowship in chronic pain management at the Cleveland Clinic in Cleveland Ohio. Dr. Gayles is an Aviation Medical Examiner (AME) and a multi-engine instrument rated pilot. His interest in aviation led him to recently join Angel Flight, a volunteer organization which transfers chronically ill patients across country via private aircraft.
To contact Dr. Gayles call 321-784-8211, or log on to YourPainInstitute.com.