News

American Forces Press Service

Pentagon Projects More Judicious Use of Nerve Agent Drug

 

 By Douglas J. Gillert
 
American Forces Press Service


 WASHINGTON -- The decision to give battlefield troops the anti-
 nerve agent drug pyridostigmine bromide won't be as easy in the 
 future as it was during the 1991 Gulf War, DoD officials said 
 Oct. 19 at the Pentagon.
 
 An estimated 250,000 U.S. service members, as well as troops 
 from other nations participating in the Gulf War, were given the 
 drug to protect them against soman, a deadly nerve agent. At the 
 time, intelligence reports couldn't confirm the presence of 
 soman in Iraqi arsenals. Instead, the decision to issue PB 
 tablets was based partially on prior Soviet possession of the 
 agent and concerns it might have been passed on to Iraq. Also, 
 Iraq was known to have used nerve agents against Iran and the 
 Kurds.
 
 "Given the deadliness of soman and the lack of other treatments 
 available, we certainly cannot rule out using PB to protect our 
 forces in the future," said Dr. Sue Bailey, assistant secretary 
 of defense for health affairs. "However, our leadership would be 
 very judicious in deciding to use PB in the future. The decision 
 would involve weighing concerns about possible long-term health 
 effects with a threat-risk assessment of how likely it is that 
 soman would be used against our troops."
 
 During the Gulf War, service members were issued PB tablets and 
 told to take them during high-threat periods. The medication 
 would bind and block an enzyme that, when attacked by soman, 
 breaks down excessive amounts of a nerve-signaling chemical, 
 acetylcholine, and leads to muscle twitching, glandular 
 secretions, abnormal moods and thinking and, at higher dose 
 levels, paralysis and respiratory failure. PB produces temporary 
 effects similar to low-level dosages of soman but it also blocks 
 the nerve agent from causing permanent damage. 
 
 However, results of studies commissioned by DoD suggest PB may 
 cause lasting effects in some humans, with symptoms of the type 
 reported by tens of thousands of Gulf War veterans. Thousands of 
 veterans have reported difficulty with sleeping, pain, mood 
 swings, muscle fatigue and memory loss. These are precisely the 
 symptoms medical research shows could be caused by PB. The 
 revelations are contained in a lengthy review of scientific 
 literature produced by the RAND Corp. and made public Oct. 19.
 
 The research, however, is inconclusive, and DoD has commissioned 
 RAND and others to continue studying PB for a more complete 
 picture. The Defense Department has directed 23 of the 26 
 federally funded PB studies currently under way. The DoD-
 commissioned studies specifically address the health 
 consequences of PB as a nerve agent pre-treatment and include 
 evaluations of the interaction of PB with other chemicals and 
 low-level exposure to nerve agents.
 
 "Most of the ongoing studies to date reveal no definitive 
 results to link PB to illnesses seen in our Persian Gulf 
 veterans," Bailey said, "but we must continue this very 
 important research to really determine any causal relationship."
 
 Dr. Beatrice Golomb, who authored the RAND review of scientific 
 literature pertaining to Gulf War illnesses, said future studies 
 will address three plausible theories on how PB may cause long-
 term or permanent health problems.
 
 One hypothesis is that people may process PB differently, making 
 some more susceptible than others to long-lasting effects. "Our 
 literature review found that the same dose administered of PB 
 would lead to sevenfold differences in blood levels of PB from 
 one individual to another," Golomb said. "Moreover, the same 
 blood level of PB may lead to widely different percentages of 
 inhibition of the enzyme."
 
 A second theory suggests that certain conditions could cause the 
 brain to absorb PB. "PB is largely barred from accessing the 
 brain by something termed 'blood-brain carrier,'" Golomb said. 
 But laboratory animal research suggests conditions such as heat, 
 stress and chemical exposures could cause more PB to pass to the 
 brain, she said.
 
 "One study suggests that PB itself may enable access to the 
 brain of substances that are normally excluded, such as 
 infectious viruses," she said. Under conditions where PB may 
 access the brain, there may be increased susceptibility to the 
 toxic effects of PB, she said.
 
 Finally, RAND will look at how and if PB is linked to chronic 
 illness in those who may have these conditions of heightened 
 susceptibility, that PB may in fact lead to permanent changes in 
 regulation of the nerve-signaling chemical acetylcholine.
 
 "The question," Golomb said, "is, could these long-lasting or 
 permanent changes in regulation of this key nerve-signaling 
 chemical be linked to illness in Gulf War veterans? And the 
 answer right now is that we simply don't know." 
 
 Bernard Rostker, DoD special assistant for Gulf War illnesses, 
 said he's frustrated no definitive cause for the illnesses has 
 been found. But even as the research continues, he said the role 
 of his office is coming to an end.
 
 "We're trying to bring to closure the various pieces of research 
 that we have outstanding," Rostker said. "We will be 
 republishing much of what we've done before to bring it up to 
 date. And then, I think, the issue becomes, where do we go in 
 the future with the whole question of deployment and the 
 outstanding work that's been done on medical force protection 
 over the last decade."
 
 All published information on the Pentagon's Gulf War illness 
 investigation is available at the GulfLINK Web site.
 
 

http://www.defenselink.mil/news/Oct1999/n10201999_9910203.html