ARTICLE=LDN AND MORPHINE

[Guest guest]

NEW YORK Jun 06, 2002 (Reuters Health) - When administered with

narcotic opioids, such as morphine and oxycodone, naltrexone in

doses 100,000 to one million times lower than that of the opioid,

not only enhances analgesia, but prevents or reverses tolerance and

physical dependency, according to a report presented here Thursday

at the International Conference on Pain and Chemical Dependency.

Implications of this finding, Dr. Stanley Crain told Reuters Health,

include the possibility that chronic pain patients may be maintained

on low, stable doses of medication. All patients with end-stage

cancer could possibly remain lucid while receiving adequate

treatment for their pain.

And, Dr. Crain theorized, this research may enable the withdrawal of

highly addictive high-dose opioid preparations, such as Oxy-Contin,

from the market because they simply will no longer be needed.

The research is based on the relatively new finding that mammals

have two opioid receptor pathways. In addition to the inhibitory

pathway that results in analgesia, there is also an excitatory

pathway that, when stimulated, weakens analgesia, mediates side

effects, and contributes to the development of tolerance and

addiction.

Dr. Crain and Dr. Ke-Fei Shen, both from the Albert Einstein School

of Medicine of Yeshiva University in New York, previously reported

that the naltrexone/opiate combination allowed low doses of morphine

to exert an analgesic effect. Administration of naltrexone in

picomolar or nanomolar amounts at the same time as opioid

administration selectively blocks the excitatory opioid pathway, Dr.

Crain explained.

He and Dr. Shen conducted hot-water-immersion tail-flick

antinociception assays with mice. Mice treated with analgesic doses

of opioids twice a day developed " a marked degree of tolerance in a

few days, " Dr. Crain said. However, when naltrexone was added at

each treatment, the mice showed " a nice, strong steady response, day

by day. "

After 5 days of opiate treatment, the animals exhibited signs of

withdrawal when the opiate was discontinued. However, Dr. Crain

said, when they were co-treated with naltrexone, no withdrawal

symptoms developed.

" Furthermore, " he added, " after having animals go through morphine

treatment for 5 days so that they become tolerant and dependent, we

can reverse the tolerance within a day if we add for the first time

the low dose of naltrexone along with the same dose of morphine. "

" In preliminary clinical trials, we have not seen any significant

signs of euphoria when morphine or oxycodone were given along with

low doses of naltrexone, even though analgesia was enhanced, " Dr.

Crain pointed out.

The company Pain Therapeutics, Inc. in San Francisco (NASDAQ:PTIE)

has patented combination products of morphine sulfate or oxycodone

and low-dose naltrexone, Dr. Crain added. According to the

company's Web site, it has completed more than 12 clinical trials,

involving over 1000 patients, that replicated these findings. The

US Food and Drug Administration has not yet reviewed the findings.

" Reuters content is the intellectual property of Reuters Limited.

Any copying, republication or redistribution of Reuters content,

including by caching, framing or similar means, is expressly

prohibited without the prior written consent of Reuters. Reuters

shall not be liable for any errors or delays in content, or for any

actions taken in reliance thereon. "

Send this article to a friend

Do you have any questions about this information? If so Ask our RN

[Guest guest]

SURE CHRIS

Sorry about the duplicate. I just saw this for the first time:can you re-post it?Thanks,Sullivan> NEW YORK Jun 06, 2002 (Reuters Health) - When administered with > narcotic opioids, such as morphine and oxycodone, naltrexone in > doses 100,000 to one million times lower than that of the opioid, > not only enhances analgesia, but prevents or reverses tolerance and > physical dependency, according to a report presented here Thursday > at the International Conference on Pain and Chemical Dependency.> > Implications of this finding, Dr. Stanley Crain told Reuters Health, > include the possibility that chronic pain patients may be maintained > on low, stable doses of medication. All patients with end-stage > cancer could possibly remain lucid while receiving adequate > treatment for their pain.> > And, Dr. Crain theorized, this research may enable the withdrawal of > highly addictive high-dose opioid preparations, such as Oxy-Contin, > from the market because they simply will no longer be needed.> > The research is based on the relatively new finding that mammals > have two opioid receptor pathways. In addition to the inhibitory > pathway that results in analgesia, there is also an excitatory > pathway that, when stimulated, weakens analgesia, mediates side > effects, and contributes to the development of tolerance and > addiction.> > Dr. Crain and Dr. Ke-Fei Shen, both from the Albert Einstein School > of Medicine of Yeshiva University in New York, previously reported > that the naltrexone/opiate combination allowed low doses of morphine > to exert an analgesic effect. Administration of naltrexone in > picomolar or nanomolar amounts at the same time as opioid > administration selectively blocks the excitatory opioid pathway, Dr. > Crain explained.> > He and Dr. Shen conducted hot-water-immersion tail-flick > antinociception assays with mice. Mice treated with analgesic doses > of opioids twice a day developed "a marked degree of tolerance in a > few days," Dr. Crain said. However, when naltrexone was added at > each treatment, the mice showed "a nice, strong steady response, day > by day."> > After 5 days of opiate treatment, the animals exhibited signs of > withdrawal when the opiate was discontinued. However, Dr. Crain > said, when they were co-treated with naltrexone, no withdrawal > symptoms developed.> > "Furthermore," he added, "after having animals go through morphine > treatment for 5 days so that they become tolerant and dependent, we > can reverse the tolerance within a day if we add for the first time > the low dose of naltrexone along with the same dose of morphine."> > "In preliminary clinical trials, we have not seen any significant > signs of euphoria when morphine or oxycodone were given along with > low doses of naltrexone, even though analgesia was enhanced," Dr. > Crain pointed out.> > The company Pain Therapeutics, Inc. in San Francisco (NASDAQ:PTIE) > has patented combination products of morphine sulfate or oxycodone > and low-dose naltrexone, Dr. Crain added. According to the > company's Web site, it has completed more than 12 clinical trials, > involving over 1000 patients, that replicated these findings. The > US Food and Drug Administration has not yet reviewed the findings.> > > > "Reuters content is the intellectual property of Reuters Limited. > Any copying, republication or redistribution of Reuters content, > including by caching, framing or similar means, is expressly > prohibited without the prior written consent of Reuters. Reuters > shall not be liable for any errors or delays in content, or for any > actions taken in reliance thereon."> > > Send this article to a friend> Do you have any questions about this information? If so Ask our RN

**************************************************************

This message was scanned by the Avast Anti-Virus Gateway

**************************************************************