Tom, I read ur other other post on naltrexone, so I assume zelnorm help with your pain but not your C?I dont know what you have read about naltrexone, so forgive me if I repeat what you already know, but im sure it will come in handy for anyone else considering using naltrexone.Zelnorm and lotronex work on 5htp4 and 5htp3 receptors respectively which block the effects of serotonin in the gut.Naltrexone is a opioid receptor antagonists so works via a different mechanism than zelnorm or lotronex. The effects of naltrexone are descibed as normalizing, so are applicable to both D and C sufferers.Personally I had great results with lotronex with a decrease in both pain and frequency (I have IBS-D) I just tried naltrexone for 6 days at 2mg each morning and had a slight improvement in pain levels but with no improvement in frequency.I dont think the action of naltrexone for IBS should be taken as being the same as for other conditions which low dose naltrexone is used for.The patent decribes dosage from .1mg/day to 5mg/day. The study included in the patent used a inital dosage of 2mg daily which was then adjusted to between 1-3mg/day. The study relating to a doseage of .5mg that all the news stories are based on, was a phase II test designed to asses safety which is required for FDA approval NOT a trial on effective dosage.So to make a long story short if nothing else has worked for your IBS-C then I would give naltrexone a go.
Hi Nath. You just mentioned something that throws me a bit, in your reference to the naltrexone study.You indicated that the dosage of 0.5 mg. was from a separate Phase II trial that only looked at safety, not IBS improvement. In looking at the release from the pharmateutical company that did the test, I found this passage:"Study Detail: The purpose of this open-label study was to evaluate the clinical effects (of naltrexone) in patients with IBS. A total of 50 patients were enrolled... Treatment consisted of 0.5 mg. dose of (naltrexone) daily over a four week period... Patients were evaluated for abdominal pain, bowel habits and stool consistency at baseline and at the end of weeks 1 through 4."It appears from my understanding of this, that the Phase II trial done with the 0.5 mg dose is also the same trial that showed that about 75% of participants noticed improvement.Were you able to find something that indicated that the 0.5 mg dose was not used to evaluate IBS improvement?Thanks,Brad
Nath, hat you read about serotonin is true but over-simplified in that thos with ibs-d seem helped by more serotonin a the 5ht3 receptor and those with c are helped by less at the 5ht4 receptor? The nalrexone seems to have a different mechanism of action and my thinking is that it might 'normalize' the opiod receptors.tom
Brad, ther are 2 studies, one being the phase II trial you mentioned and the other being the studied conducted for the patent.The primary goal of the Phase 2 trial was saftey and the FDA requires these studies to meet certain requirements.Quote from Remi Barbier, president and chief executive officer of Pain Therapeutics http://www.msnbc.com/news/919653.asp?cp1=1 "The phase II test was designed mostly to assess safety, and the company now plans to start a larger, Phase III efficacy trial ï¿½ the last step before seeking FDA approval."Secondary was relief of symtoms, but during the study they did not adjust the dose, as the aim was not to establish a recommended dose.The study in the patent was started at 2mg/day then adjusted to between 1-3mg/day, adjusting dosage for each individual.So my point was the 2mg/day dose is probably a more accurate representation of what people would require in the real world. But you are right that phase II study did report a 75% inprovement in patients.Tom, I dont know anything about the comparative effects of 5htp antagonists, but it is my understanding that lotronex blocks the action of seroton at the 5htp-3 receptor while zelnorm blocks serotonin at the 5htp-4 receptor. My thinking is that these two receptors modulate gut motility in combination. As for naltrexone, yes naltrexone has a completly different mechanism of action, so is a completely different class of drug.Quote from same guy as above: ï¿½The traditional view of IBS is that the flusher is broken ï¿½ it iseither flushing too quickly or not quickly enough, causing diarrhea or constipation,ï¿½ Barbier said.ï¿½We disagree with that point of view. We donï¿½t think the flusher is the problem. We think it is an imbalance of opioids in the gut. We provide the patient with an external source of opioid antagonists to restore bowel function.ï¿½So yeah their view is that naltrexone normalizes the opioids in the gut.
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