November 15, 2006
AP Photo/Michael ProbstFollowing more than 200 reports over six years of adverse psychiatric effects in minors taking the drug Tamiflu, including 15 deaths, the FDA has made an addition to the drug's warning label. It cautions parents to watch out for "an increased risk of self-injury and confusion" in children, which could begin within a day of starting on the drug. Almost all of the reports of psychiatric issues have come out of Japan, which uses more Tamiflu than any other country in the world. The first 126 reports were spread out between 1999 and 2005, and the FDA did not believe the evidence warranted a change to the label. But when another 103 reports flooded in between 2005 and 2006, the FDA decided to act on the side of caution.
Tamiflu is not a flu vaccine. It is an oral, anti-viral drug that is supposed to shorten the duration and the severity of the flu once someone already has it. It's in a class of drugs called neuraminidase inhibitors, and it prevents the flu virus from escaping from an infected cell, effectively stemming its spread. Flu patients have to start taking the drug within 48 hours of their first flu symptom in order for it to be effective, and the regimen is five days long.
Beginning in 1999, reports of strange behaviors in pediatric patients began to come out of the Japanese health ministry. Mostly affecting Tamiflu takers under the age of 17, psychiatric issues like sudden aggression, disorientation, delirium, hallucinations, self-injury, suicidal thoughts, suicide, and death from falls and other accidents started to arise. Twelve children died between 2004 and 2005, and three died between 2005 and 2006. One of the most obvious questions here is why Japan is so severely over-represented in these events. The FDA has several working hypotheses:
Since Japan uses far more Tamiflu than any other country, it's possible that these side effects are simply so rare that they only occur when prescriptions pass a certain threshold.
Due to an increased occurrence of flu-related encephalitis (brain swelling) in the past several years in Japan (which is also part of the reason why Japan uses so much Tamiflu -- to prevent this flu side effect), Japan's health ministry requires incredibly strict reporting of all adverse effects related to flu infection. It's possible that these psychiatric symptoms are happening elsewhere but are not being reported.
It's possible (but scientifically unlikely) that Japanese patients metabolize Tamiflu differently than patients of other ethnicities. Even with a growing number of doctors making the connection between the behavioral symptoms and Tamiflu, both the FDA and the drug's maker, Roche, say there is not enough clear evidence to establish a direct cause-and-effect relationship between the drug and the abnormal behaviors. They note that severe cases of the flu virus itself can cause adverse psychiatric symptoms, so it's very difficult to determine if the behaviors are a result of the flu or of the antiviral drug being taken to treat it. One of the major concerns right now is that Tamiflu is the only approved, oral neuraminidase inhibitor on the market, and experts believe it will be a crucial tool in stopping a bird-flu pandemic if the disease ever mutates into a form that transmits easily from human to human. In the current climate, the FDA does not want to imply that Tamiflu is unsafe without very solid evidence to that effect. Also, discouraging people from taking Tamiflu could end up increasing the number of deaths from the untreated flu virus.
In the meantime, if you or your child is taking Tamiflu, watch carefully for strange behavior and call your doctor immediately if you observe something out of the ordinary. The FDA also recommends getting the flu vaccine in order to avoid having to treat the virus in the first place.
For more information on Tamiflu, influenza and related topics, check out the following links:
Mental side-effect warnings sought for flu drugs
http://seattletimes.nwsource.com/html/nationworld/2004032250_tamiflu24.html
By Christopher Lee The Washington Post
WASHINGTON — Food and Drug Administration (FDA) experts are recommending new label warnings about possible dangerous psychiatric side effects of influenza drugs Tamiflu and Relenza, documents show.
The FDA documents, posted Friday on the agency's Web site, were prepared for a meeting Tuesday of the FDA's Pediatric Advisory Committee.
Studies revealed 596 cases in which patients who took Tamiflu experienced "neuropsychiatric events" such as delirium, delusions or hallucinations. The episodes sometimes led to impulsive behavior and self-injury. Tamiflu is made by Roche Holdings.
The problems tended to occur within 24 hours of first taking the drug, and the majority were in patients younger than 21, mostly in Japan, according to the documents. In five cases involving pediatric patients, the reported delirium resulted in death, and there were three reports of suicide in adults.
"In the remaining reports of delirium with impulsive behavior and self-injury, patients were attempting to flee or escape from windows or balconies and were unsuccessful in their efforts," the FDA documents say.
Tamiflu, available in pill and syrup form, can treat the symptoms of seasonal influenza. In a bird-flu pandemic, many experts think the drug could help reduce the length and severity of symptoms.
Safety concerns about Tamiflu arose two years ago after reports of 12 deaths and 32 cases of psychiatric problems in children in Japan. Labeling for Tamiflu in the United States notes that self-injury and delirium have occurred, primarily among pediatric patients.
Now FDA regulators are recommending that U.S. labeling be updated to note that "fatalities have occurred in adult and pediatric patients in Japan, the onset may be abrupt, and fatal events have occurred even while the patient was being monitored."
Regulators cautioned that no causal link has been established between the drug and the abnormal behavior, and that delirium and other problems can be complications of influenza.
Roche spokesman Terry Hurley said reports of abnormal behavior were "infrequent."
Regarding Relenza, an antiviral drug made by GlaxoSmithKline that is in the same class as Tamiflu, FDA experts said studies turned up 115 cases of psychiatric problems, including 74 cases in patients younger than 21. Seventy percent were in Japan. No potentially related deaths were reported.
Because Relenza, which is inhaled by mouth, is not easily absorbed, experts said the problems probably were related to the influenza rather than the treatment.
Nevertheless, they recommended updating Relenza's label to note that "postmarketing reports of hallucinations, delirium and abnormal behavior have been observed in patients" receiving the drug for treatment of influenza. The label does not warn of psychiatric side effects.
Glaxo spokesman Jeff McLaughlin said, "A review of clinical trial data and postmarketing reports demonstrated no evidence of a causal association between Relenza and neuropsychiatric adverse events."
William Schaffner, chairman of the Department of Preventive Medicine at Vanderbilt University School of Medicine in Nashville, Tenn., said the proposed warnings are "prudent and appropriate."
By Christopher Lee The Washington Post
WASHINGTON — Food and Drug Administration (FDA) experts are recommending new label warnings about possible dangerous psychiatric side effects of influenza drugs Tamiflu and Relenza, documents show.
The FDA documents, posted Friday on the agency's Web site, were prepared for a meeting Tuesday of the FDA's Pediatric Advisory Committee.
Studies revealed 596 cases in which patients who took Tamiflu experienced "neuropsychiatric events" such as delirium, delusions or hallucinations. The episodes sometimes led to impulsive behavior and self-injury. Tamiflu is made by Roche Holdings.
The problems tended to occur within 24 hours of first taking the drug, and the majority were in patients younger than 21, mostly in Japan, according to the documents. In five cases involving pediatric patients, the reported delirium resulted in death, and there were three reports of suicide in adults.
"In the remaining reports of delirium with impulsive behavior and self-injury, patients were attempting to flee or escape from windows or balconies and were unsuccessful in their efforts," the FDA documents say.
Tamiflu, available in pill and syrup form, can treat the symptoms of seasonal influenza. In a bird-flu pandemic, many experts think the drug could help reduce the length and severity of symptoms.
Safety concerns about Tamiflu arose two years ago after reports of 12 deaths and 32 cases of psychiatric problems in children in Japan. Labeling for Tamiflu in the United States notes that self-injury and delirium have occurred, primarily among pediatric patients.
Now FDA regulators are recommending that U.S. labeling be updated to note that "fatalities have occurred in adult and pediatric patients in Japan, the onset may be abrupt, and fatal events have occurred even while the patient was being monitored."
Regulators cautioned that no causal link has been established between the drug and the abnormal behavior, and that delirium and other problems can be complications of influenza.
Roche spokesman Terry Hurley said reports of abnormal behavior were "infrequent."
Regarding Relenza, an antiviral drug made by GlaxoSmithKline that is in the same class as Tamiflu, FDA experts said studies turned up 115 cases of psychiatric problems, including 74 cases in patients younger than 21. Seventy percent were in Japan. No potentially related deaths were reported.
Because Relenza, which is inhaled by mouth, is not easily absorbed, experts said the problems probably were related to the influenza rather than the treatment.
Nevertheless, they recommended updating Relenza's label to note that "postmarketing reports of hallucinations, delirium and abnormal behavior have been observed in patients" receiving the drug for treatment of influenza. The label does not warn of psychiatric side effects.
Glaxo spokesman Jeff McLaughlin said, "A review of clinical trial data and postmarketing reports demonstrated no evidence of a causal association between Relenza and neuropsychiatric adverse events."
William Schaffner, chairman of the Department of Preventive Medicine at Vanderbilt University School of Medicine in Nashville, Tenn., said the proposed warnings are "prudent and appropriate."
今年流感大爆發？ 流感之父拉維博士：數萬人將喪命
更新日期:2007/11/25 12:16 生活中心／綜合報導
曾經發明流行性感冒疫苗，並且被學術界稱之為「流感之父」的澳洲生化學家拉維博士預告，2007年冬天全球可能會爆發嚴重的流感疫情，造成數萬人喪生，屆時恐怕連流感疫苗都無法抵擋。他同時呼籲，應該將克流感（Tamiflu）、瑞樂沙（Relenza）等疫苗改為非處方箋用藥。
拉維博士呼籲，各國政府應該開始大量製造克流感，以及瑞樂沙等感冒藥，並且必須開放這類感冒藥物為非處方藥，讓所有有需要的民眾都能及時取得，到時候才能有效阻止流感疫情的擴散。
拉維博士過去曾任教於澳洲首都坎培拉的澳洲國立大學生化學系，他對「涎酸酵素」這種流感病毒表面蛋白質的研究，也使他成為研發流感疫苗的第一人，學術界給與他「流感之父」的稱號。拉維博士表示，「如果英國也發生與澳洲過去爆發的季節性流感，可能會讓成千上萬人感染流感，而最後引發許多人死亡。」
不過，治療流感的克流感(Tamiflu)，卻在日本卻傳出有青少年，在服用克流感後產生幻覺；美國食品藥物管理局FDA委員會將在27日討論，是否對克流感及同屬抗感冒病毒藥物瑞樂沙(Relenza)，新增神經學異常的警語，並建議使用者應保持警戒；對此，國內醫師則表示，「流感本來就可能引發神經症狀異常與服用抗病毒藥物，應該是沒有關聯。」
更新日期:2007/11/25 12:16 生活中心／綜合報導
曾經發明流行性感冒疫苗，並且被學術界稱之為「流感之父」的澳洲生化學家拉維博士預告，2007年冬天全球可能會爆發嚴重的流感疫情，造成數萬人喪生，屆時恐怕連流感疫苗都無法抵擋。他同時呼籲，應該將克流感（Tamiflu）、瑞樂沙（Relenza）等疫苗改為非處方箋用藥。
拉維博士呼籲，各國政府應該開始大量製造克流感，以及瑞樂沙等感冒藥，並且必須開放這類感冒藥物為非處方藥，讓所有有需要的民眾都能及時取得，到時候才能有效阻止流感疫情的擴散。
拉維博士過去曾任教於澳洲首都坎培拉的澳洲國立大學生化學系，他對「涎酸酵素」這種流感病毒表面蛋白質的研究，也使他成為研發流感疫苗的第一人，學術界給與他「流感之父」的稱號。拉維博士表示，「如果英國也發生與澳洲過去爆發的季節性流感，可能會讓成千上萬人感染流感，而最後引發許多人死亡。」
不過，治療流感的克流感(Tamiflu)，卻在日本卻傳出有青少年，在服用克流感後產生幻覺；美國食品藥物管理局FDA委員會將在27日討論，是否對克流感及同屬抗感冒病毒藥物瑞樂沙(Relenza)，新增神經學異常的警語，並建議使用者應保持警戒；對此，國內醫師則表示，「流感本來就可能引發神經症狀異常與服用抗病毒藥物，應該是沒有關聯。」
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