A Tamiflu – Resistant Strain of Swine Flu. A Tamiflu-resistant strain of Swine Flu—the 2009 H1N1 pandemic virus—has emerged in Denmark. According to Bloomberg.com, Tamiflu drug maker Roche Holding AG said a patient treated with the Tamiflu in Denmark exhibited drug resistance, the first time this has occurred in this outbreak.
Bloomberg.com said the swine flu patient received a low and preventative dose of Tamiflu after coming in contact with someone infected with the virus, said David Reddy, Roche’s influenza task force head. Speaking on a conference call, Reddy said that the patient developed flu symptoms and was diagnosed with a virus mutation that showed resistance to Tam,iflu reported Bloomberg.com.
The Food & Drug Administration (FDA) has approved two antiviral drugs for treatment and prophylaxis of the 2009 H1N1 influenza virus: Tamiflu (oseltamivir phosphate) and Relenza (zanamivir). Tamiflu and Relenza, in addition to their approved labeling, have Emergency Use Authorizations that describe specific permitted uses during this public health emergency.
The BBC explained that Tamiflu is the primary drug being used to fight the swine flu pandemic. Also, according to Reddy, said the BBC, drug resistance was not unexpected, citing that the same can occur with the more common seasonal flu.
There Are No Other Known Cases of the Resistant Strain
Bloomberg.com reported that the patient has recovered and there are no other known cases of the resistant strain, citing Denmark’s National Board of Health. Reddy did point out that according to Tamiflu studies, about 0.4 percent of adults and four percent of children who come down with seasonal influenza develop resistance, “We know from seasonal flu that a proportion of patients can develop resistance,” Reddy said, quoted Bloomberg.com. “We fully expect that this also can occur during treatment with a new flu strain,” Reddy added.
According to Reddy, there are no signs of a Tamiflu-resistant strain of H1N1 circulating, unlike the seasonal H1N1 flu in which Tamiflu-resistant strain emerged in 2009 and is now quite common, said the BBC. The BBC pointed out that experts are concerned that if this were to happen, it could cause Tamiflu to become ineffective.
Britain’s Health Protection Agency said it, “continues to watch for antiviral resistance and will be carrying out regular sample testing throughout this outbreak. We have been monitoring antiviral drug resistance since the beginning of this outbreak,” quoted the BBC. The swine flu virus has killed over 300 people worldwide and the World Health Organization (WHO) just announced that 70,893 cases have been reported around the world, said Bloomberg.com.
We recently reported that the FDA released another warning about bogus flu products that are targeting consumers via Websites. The agency stated it is enforcing the laws that protect consumers from illegal products marketed through the Internet that claim to diagnose, prevent, mitigate, treat, or cure the 2009 H1N1 flu virus, but which are not approved, cleared, or authorized by the FDA
Also, in late 2006, the FDA alerted doctors and parents to watch for signs of bizarre behavior in children treated with Tamiflu after federal health officials noticed an increasing number of such cases overseas. There have been reports of 596 neuropsychiatric events, including 16 neuropsychiatric-related deaths, among children and adults taking Tamiflu, according to documents posted online at the FDA’s Website. Japan was also the origin of 81 Relenza reports and, according to Health Canada’s adverse reaction database, 27 people reported adverse reactions to Relenza, including one adult who died. One 14-year-old reported nightmares and another six-year-old temporarily lost consciousness. Another 96 people reported adverse reactions to Tamiflu, including 11 adults who died and nine who reported psychiatric problems.