To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: IHC: Established Cutaneous Allodynia Thwarts Triptans Ability to Abort Migraine Headaches URL: http://www.pslgroup.com/dg/23A2B2.htm Doctor's Guide September 16, 2003
By Larry Schuster ROME, ITALY -- September 16, 2003 -- Fully established cutaneous allodynia in migraine sufferers appears to greatly reduce the efficacy of triptans to abort migraines, researchers reported here September 13th at the 11th Congress of the International Headache Society. "The study of 61 migraine attacks provides new support for the rapid use of triptans in allodynic patients to prevent full establishment of migraine," said lead researcher Rami Burstein, MD, Harvard Medical School, Boston, Massachusetts, United States. Researchers have long reported that they have been getting about 50% of patients into a pain-free state using triptans, and Dr. Burstein's group achieved similar results. "Pain-free" was defined as pain-free at 2 hours and sustained for 24 hours, Dr. Burstein explained. "If you analyse these same data based on absence or presence of cutaneous allodynia at the time of treatment, we see that in the absence of allodynia, the pain-free rate flies up to 93%," noted Dr. Burstein. "In the presence of allodynia, the pain remains in about 85% [of patients]. We are suggesting that only by timing the treatment of triptan can we increase the success rate in getting patients [to be] pain-free." Based on the timetable for the development of cutaneous allodynia, Dr. Burstein introduced triptans in patients during both the migraine developing phase and the established migraine phase, as well as during early and late phases in non-allodynic patients. "We found that as long as migraine attacks are not associated with allodynia at the time of treatment, triptans are very effective at rendering these patients completely pain-free, regardless of whether the treatment is given early or late into the attack," noted Dr. Burstein. "In contrast, when migraine attacks are associated with allodynia at the time of treatment, triptans can only partially heal the patient," with a success rate of 20% to 40%, when the patient does not receive triptans within the first hour of the migraine onset. To illustrate those findings, Dr. Burstein injected a non-allodynic patient with triptans during two different migraine attacks, once at 1 hour and once at 4 hours. In both cases, the patient was rendered pain-free. In an allodynic patient, however, when triptans were administered at 4 hours after onset of migraine, skin sensitivity had been abnormal for several hours, and probably in the established phase of allodynia, it was noted. Triptan injection did not abort the migraine nor treat the allodynia. In the same patient, using the same drug at 1 hour, when the allodynia was just beginning, an injection aborted the migraine and rendered the patient pain-free. In his abstract, Dr. Burstein wrote: "Triptans prevent the induction of sensitization in central but not peripheral trigeminovascular neurons, and triptans cannot abolish already established peripheral or central sensitization." In his presentation, Dr. Burstein said that these results indicate that the developing phase, which happens early in the attack, is the time when the activity from the central nervous system depends on the pain signals from the dura. "If we shut it down it will go back to its normal state," he said. That migraine neuronal activity can only be shut down before it becomes firmly established in the central nervous system. Dr. Burstein also presented data confirming clinical experience that triptans actually make the pain worse for the first 15 to 20 minutes before providing pain relief. "His findings challenge the traditional view that vasodilation is the basis of migraine, and that triptans penetrate the central nervous system," said Marc Cantillon, MD, neuropsychiatrist, Livingston, New Jersey, United States. Dr. Cantillon said in an interview that Dr. Burstein implied this was only a part of the story, and that so far no drug has been effective in cases of established allodynia. "He is [effectively] saying 'Go back and get something that works' [on the many cases of migraine associated with allodynia]," said Dr. Cantillon, noting that 70% of patients have allodynia. Dr. Cantillon is working with NPS Pharmaceuticals in Parsippany, New Jersey, to develop a new migraine treatment. "These findings make it all the more important for physicians to determine whether a migraine patient is allodynic, and to motivate allodynic patients to take triptans at the earliest sign of migraine (if possible within 20 minutes of onset)," Dr. Burstein said. Very often, he noted, patients are not taking triptans until 2 to 4 hours after onset. --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. 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