Washington ( CNN ) -- Two women who say they suffered severe medical complications from a generic drug lost their Supreme Court appeal Thursday , essentially ending their separate lawsuits against pharmaceutical manufacturers . The justices in a 5-4 ruling said generic drug companies do not share the same level of responsibility as makers of brand-name equivalents , to update their warning labels when significant new risks emerge . The financial and safety implications from the court 's ruling , could prove enormous . Generic drugs currently account for more than 70 % of prescriptions filled in the United States . That number is expected to rise in the coming years , with patent protection due to expire on several popular and lucrative consumer drugs , including Lipitor and Viagra . The blockbuster health care reform bill championed by President Barack Obama would also encourage greater use of generics . About a third of generic drugs have no brand name competitors . The court split along conservative-liberal lines . `` It is beyond dispute that the federal statutes and regulations that apply to brand-name drug manufacturers are meaningfully different than those that apply to generic drug manufacturers , '' said Justice Clarence Thomas . `` Indeed it is the special , and different , regulation of generic drugs that allowed the generic drug market to expand , bringing drugs more quickly and cheaply to the public . '' In dissent , Justice Sonia Sotomayor countered , `` These divergent liability rules threaten to reduce consumer demand for generics ... Nothing in the court 's opinion convinces me that , in enacting the requirement that generic labels match their corresponding brand-name labels , Congress intended these results . '' Justices Ruth Bader Ginsburg , Stephen Breyer , and Elena Kagan supported Sotomayor . Gladys Mensing of Minnesota and Julie Demahy of Louisiana both were prescribed metoclopramide -- marketed as Reglan by Wyeth Pharmaceuticals -- to treat their heartburn and acid reflux . Their pharmacists separately filled the prescription with a generic equivalent made by PLIVA , Inc. and Actavis , Inc. After four years of taking the drugs , the women each developed tardive dyskinesia , a severe longterm neurological disorder that causes involuntary muscle movements . They sued the generic manufacturers of the metoclopramide , claiming that inadequate warnings were provided about the long-term risks of taking the medicine . It was also alleged there was growing evidence of the dangers posed by the drug , but that the companies took no steps to change the warning labels . In 2009 , the FDA acted on its own and issued an order to the makers of both brand-name and generic versions of metoclopramide to add a specific warning about the increased risks of developing tardive dyskinesia . The generic drug makers are trying to dismiss the lawsuits . They cite a 1984 congressional law pre-empting state `` failure-to-warn '' claims . Drug companies have long asserted various doctrines of pre-emption , saying they are protected from most product-liability claims if they have met federal safety approval standards . They argue that federal regulatory judgments trump state consumer safety laws , which are often tougher than Washington 's standards . But the high court had given a big victory to patients and consumer rights groups in 2009 when it ruled in favor of plaintiff Diana Winn Levine , when she sued Wyeth -- now owned by Pfizer -- after losing an arm to gangrene from a common , brand-name anti-nausea prescription medication . She had won a $ 7 million judgment from a Vermont jury for her claims . Thomas acknowledged that from the plaintiffs ' perspective in the latest cases , `` finding pre-emption here but not in Wyeth makes little sense . '' But he added , `` because pharmacists , acting in full accord with state law , substituted generic metoclopramide instead , federal law pre-empts these lawsuits . We acknowledge the unfortunate hand that federal drug regulation has dealt Mensing , Demahy and others similarly situated . '' The majority noted Congress and the FDA , not the courts , can now change the law if they want . Sotomayor , expressing her frustration , said , `` As a result of today 's decision , whether a consumer harmed by inadequate warnings can obtain relief turns solely on the happenstance of whether her pharmacist filled her prescription with a brand-name or generic drug . The court gets one thing right : This outcome makes little sense . '' The American Association of Justice -- representing trial attorneys -- said the ruling was `` disastrous '' for consumers . `` Patients will now be taking generic drugs at their own risk , '' said the group 's president Gibson Vance . `` It is absurd that doctors and patients will have to make medical decisions knowing that only brand-name drug manufacturers -- not generics -- can be held accountable for their drugs ' dangerous side-effects . '' But one of the generic drug makers sued applauded the high court 's decision . `` This ruling furthers meaningful consumer protection while also safeguarding against lawsuits that threaten the availability of safe and affordable pharmaceutical products by misconstruing the labeling responsibilities of generic manufacturers , '' said Activis CEO Doug Boothe . The Obama administration was backing the plaintiffs , concerned that if state lawsuits are pre-empted by federal law , that will reduce the incentive for generic drug makers to provide the most current safety information to the FDA .
Court : Generic drug companies do n't have same responsibility as makers of name brands . Comment: Sotomayor : `` These divergent liability rules threaten to reduce consumer demand for generics ''