Neuropathic pain

[Guest guest]

http://www.ntii.com/memweb.htm

This is rather interesting about neuropathic pain.

It is in regard to the med Memantine.

An excerpt for those who don't care to read the entire article.

In the absence of clinical data from placebo-controlled human trials of

analgesics for neuropathic pain, physicians now prescribe a variety of

analgesics for pain management. These include anti-depressants such as

amitriptylene and non-steroidal anti-inflammatory drugs (NSAID's) such as

ibuprofen. Anti-convulsives such as carbamazepine, phenytoin or (more

recently) gabapentin are prescribed for shocking or lancinating pain. Opioids

such as codeine are also used. These medications have been found to provide

partial pain relief for many patients. However, responses are highly

variable, especially when pain becomes severe.

All these analgesics may also cause serious adverse side effects when

administered chronically at high doses. Complications caused by high dose

NSAID's are responsible for 40,000 hospitalizations in the U.S. annually, due

chiefly to bleeding ulcers. Anti-depressants have potential side effects

(such as sedation and weight gain) and patients must typically receive

anti-depressant medication for several weeks before its analgesic effects can

be assessed. Chronic therapy with anti-convulsives may produce adverse

effects such as somnolence, nausea, vertigo, dizziness, and loss of balance.

Opioids are associated with adverse side effects which can be dose limiting,

including nausea, vomiting, sedation, mental confusion, and constipation.

Capsaicin, a topical cream, is available without a prescription and appears

to provide some benefit to patients with neuropathic pain. Capsaicin is the

active substance in hot peppers and is believed to reduce pain transmission

from the periphery to the CNS by depleting stores of neurotransmitters in

sensory neurons. It may cause burning and redness at the site of application.

Many patients do not receive adequate pain control from existing treatments.

There is a major medical need for a safe, effective therapy to treat

neuropathic pain.

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Diabetic neuropathy pain is very much like CMT neuropathic pain.

In the U.S., NTI® completed a 421-patient Phase IIB trial of Memantine for

neuropathic pain due to diabetic neuropathy. In January 2000, NTI® announced

the completion of their randomized, double-blind, placebo-controlled,

dose-ranging Phase IIB trial which was held at 21 trial sites nationwide and

jointly managed by Quintilles CNS Therapeutics. Patients were required to

have a minimum mean pain intensity rating of 30 mm prior to enrollment.

Patients were randomized to one of three treatment groups. Two groups of

patients received twice daily oral doses of Memantine, escalating to either

20 mg or 40 mg; the remaining patients received placebo. This three-armed

study comparing daily doses of placebo, 20 mg and 40 mg of Memantine,

demonstrated statistically significantly less nocturnal pain intensity with

40 mg of Memantine compared to placebo after eight weeks of dosing. In the

group dosed with 20 mg of Memantine, positive trends were seen, but

statistical significance was not observed. The company will present the

complete results of the Phase IIB trial at the 52nd Annual Meeting of the

American Academy of Neurology in San Diego, April 29 - May 6, 2000.

=========== different article =======

DRUG COMBATS COMMON PAIN IN DIABETICS: An experimental drug shows promise in

treating painful diabetic neuropathy, a condition that severely impacts the

quality of life for about 5 million people in the United States, researchers

report at the annual meeting of the American Academy of Neurology. In the

largest study of its kind, doctors say 44 percent of the 200 patients taking

the drug memantine reported a reduction in pain associated with diabetes by

50 percent. Twenty-nine percent of 200 patients who took a placebo, or sugar

pill, reported similar relief. Chief investigator Dr. Pellegrino says

about 40 to 50 percent of diabetics develop the neuropathy, which some

describe as a sensation like sandpaper or burning-so intense that it can

prevent sleep. Pellegrino, president of Central Arkansas Research Inc., Hot

Springs, says few drugs can currently treat the condition. Memantine has been

used in Europe for treatment of dementia and other degenerative diseases.

Copyright 2000 by United Press International.

All rights reserved.