pliva et al mensing argued march decided june five years food drug administration fda first approved metoclopramide drug commonly used treat digestive tract problems brand name reglan generic manufacturers petitioners also began producing drug accumulating evidence metoclopramide use cause tardive dyskinesia severe neurological disorder warning labels drug strengthened clarified several times recently respondents prescribed reglan received generic drug pharmacists taking drug prescribed several years developed tardive dyskinesia separate tort actions sued petitioners generic drug manufacturers produced metoclopramide took manufacturers respondent alleged inter alia metoclopramide use caused disorder manufacturers liable state tort law failing provide adequate warning labels suits manufacturers urged federal statutes fda regulations state tort claims requiring safety efficacy labeling generic metoclopramide mandated time reglan fifth eighth circuits rejected arguments holding respondents claims held judgment reversed cases remanded reversed remanded justice thomas delivered opinion respect part concluding federal drug regulations applicable generic drug manufacturers directly conflict thus state claims pp analysis requires comparison federal state law begins identifying state tort duties federal labeling requirements applicable manufacturers pp state tort law requires manufacturer aware drug danger label way renders reasonably safe respondents pleaded manufacturers knew known use products carried high risk tardive dyskinesia labels adequately warn risk taking allegations true duty required manufacturers use different stronger label one actually used pp hand federal drug regulations interpreted fda prevented manufacturers independently changing generic drugs safety labels manufacturer seeking federal approval market new drug must prove safe effective proposed label accurate adequate although rules originally applied drugs law commonly called amendments allows generic drug manufacturer gain fda approval simply showing drug equivalent drug safety efficacy labeling proposed drug approved drug respondents contend federal law nevertheless provides avenues manufacturers altered metoclopramide labels time prevent injuries include fda cbe process permits drug manufacturers without preapproval add strengthen warning label sending dear doctor letters providing additional warnings prescribing physicians healthcare professionals however fda denies manufacturers used either processes unilaterally strengthen warning labels defers fda views plainly erroneous inconsistent regulations reason doubt reflect fda fair considered judgment auer robbins assuming without deciding fda correct federal law nevertheless required manufacturers ask agency assistance convincing manufacturer adopt stronger label turns question pp state federal law directly conflict state law must give way see wyeth levine conflict exists impossible private party comply state federal requirements freightliner myrick pp finds impossibility manufacturers independently changed labels satisfy duty attach safer label generic metoclopramide violated federal requirement generic drug labels corresponding drug labels thus impossible comply state federal law even fulfilled federal duty ask fda help strengthening corresponding label assuming duty exists satisfied state duty state law demanded safer label require communication fda possibility safer label pp rejects argument manufacturers defense fails failed ask fda help changing corresponding label proper question impossibility analysis whether private party independently federal law state law requires see wyeth supra accepting respondents argument render conflict largely meaningless making conflicts state federal law illusory cases possible manufacturers asked fda help might eventually able strengthen warning label also possible convinced fda reinterpret regulations manner opened cbe process persuaded fda rewrite generic drug regulations entirely talked congress amending amendments conjectures sufficed prevent federal state law conflicting unclear outside express supremacy clause force clause makes federal law law land thing constitution laws state contrary notwithstanding art vi cl read permit approach renders conflict meaningless enough hold party satisfy state duties without federal government special permission assistance dependent exercise judgment federal agency party independently satisfy state duties purposes pp wyeth contrary held state tort action drug manufacturer failure provide adequate warning label possible manufacturer comply state federal law fda cbe regulation federal statutes regulations apply drug manufacturers differ congress design applicable generic drug manufacturers different federal statutes regulations may lead different results distort supremacy clause order create similar across dissimilar statutory scheme congress fda retain authority change law regulations desire pp thomas delivered opinion except part roberts scalia alito joined opinion full kennedy joined part sotomayor filed dissenting opinion ginsburg breyer kagan joined pliva et petitioners gladys mensing actavis elizabeth llc petitioner gladys mensing actavis petitioner julie demahy writs certiorari courts appeals eighth fifth circuits june justice thomas delivered opinion part consolidated lawsuits involve state claims based certain drug manufacturers alleged failure provide adequate warning labels generic metoclopramide question presented whether federal drug regulations applicable generic drug manufacturers directly conflict thus claims hold metoclopramide drug designed speed movement food digestive system food drug administration fda first approved metoclopramide tablets brand name reglan five years later generic manufacturers also began producing drug commonly used treat digestive tract problems diabetic gastroparesis gastroesophageal reflux disorder evidence accumulated metoclopramide use cause tardive dyskinesia severe neurological disorder studies shown patients take metoclopramide several years develop condition mcneil wyeth see also shaffer butterfield pamer mackey tardive dyskinesia risks metoclopramide use market withdrawal cisapride pharmacists assn noting cases tardive dyskinesia reported fda adverse event reporting system accordingly warning labels drug strengthened clarified several times label modified warn tardive dyskinesia may develop patients treated metoclopramide drug package insert added herapy longer weeks evaluated recommended physician desk reference ed see also brief petitioner pliva et al hereinafter pliva brief reglan manufacturer requested fda approved label change add herapy exceed weeks duration brief amicus curiae hereinafter brief fda ordered black box warning strongest treatment metoclopramide cause tardive dyskinesia serious movement disorder often irreversible treatment metoclopramide longer weeks avoided rare cases see physician desk reference ed gladys mensing julie demahy plaintiffs consolidated cases prescribed reglan respectively received generic metoclopramide pharmacists taking drug prescribed several years women developed tardive dyskinesia separate suits mensing demahy sued generic drug manufacturers produced metoclopramide took manufacturers alleged relevant metoclopramide use caused dyskinesia manufacturers liable state tort law specifically minnesota louisiana failing provide adequate warning labels claimed despite mounting evidence long term metoclopramide use carries risk tardive dyskinesia far greater indicated label none manufacturers changed labels adequately warn danger mensing wyeth see also demahy actavis suits manufacturers urged federal law state tort claims according manufacturers federal statutes fda regulations required use safety efficacy labeling counterparts means argued impossible simultaneously comply federal law state duty required use different label courts appeals fifth eighth circuits rejected manufacturers arguments held demahy claims see granted certiorari consolidated cases reverse ii analysis requires us compare federal state law therefore begin identifying state tort duties federal labeling requirements applicable manufacturers undisputed minnesota louisiana tort law require drug manufacturer aware product danger label product way renders reasonably safe minnesota law applies mensing lawsuit manufacturer product actual constructive knowledge danger users manufacturer duty give warning dangers frey montgomery ward similarly louisiana law applicable demahy lawsuit manufacturer duty warn includes duty provide adequate instructions safe use product stahl novartis pharmaceuticals see also la rev stat ann west duty warn falls specifically manufacturer see marks ohmeda pp la app gray badger min mensing demahy pleaded manufacturers knew known high risk tardive dyskinesia inherent use product also pleaded manufacturers knew known labels adequately warn risk app parties dispute allegations true state law required manufacturers use different safer label federal law imposes far complex drug labeling requirements begin dispute drug amendments federal food drug cosmetic act stat et manufacturer seeking federal approval market new drug must prove safe effective proposed label accurate see wyeth levine meeting requirements involves costly lengthy clinical testing see also beers generic innovator drugs guide fda approval requirements ed originally rules applied drugs however congress passed drug price competition patent term restoration act stat commonly called amendments law generic drugs gain fda approval simply showing equivalence reference listed drug already approved allows manufacturers develop generic drugs without duplicating clinical trials already performed equivalent drug generic drug application must also show safety efficacy labeling proposed labeling approved drug see also beers result generic drug manufacturers different federal drug labeling duties manufacturer seeking new drug approval responsible accuracy adequacy label see wyeth supra manufacturer seeking generic drug approval hand responsible ensuring warning label brand name see cfr parties disagree dispute whether extent generic manufacturers may change labels initial fda approval mensing demahy contend federal law provided several avenues manufacturers altered metoclopramide labels time prevent injuries fda however tells us interprets regulations require warning labels drug generic copy must always thus generic drug manufacturers ongoing federal duty sameness brief see also fed reg generic drug labeling must listed drug product labeling listed drug product basis generic drug fda views controlling unless plainly erroneous inconsistent regulation reason doubt reflect fda fair considered judgment auer robbins internal quotation marks omitted first mensing demahy urge fda cbe process allowed manufacturers change labels necessary see brief respondents see also gaeta perrigo pharmaceuticals foster american home prods cbe process permits drug manufacturers add strengthen contraindication warning precaution cfr iii add strengthen instruction dosage administration intended increase safe use drug product iii making labeling changes using cbe process drug need wait preapproval fda ordinarily necessary change label wyeth supra need simultaneously file supplemental application fda cfr fda denies manufacturers used cbe process unilaterally strengthen warning labels agency interprets cbe regulation allow changes generic drug labels generic drug manufacturer changes label match updated label follow fda instructions brief interpreting cfr iv brief fda argues cbe changes unilaterally made strengthen generic drug warning label violate statutes regulations requiring generic drug label match counterpart see also cfr iii approval may withdrawn generic drug label longer consistent defer fda interpretation cbe generic labeling regulations although mensing demahy offer ways interpret regulations see brief respondents find agency interpretation plainly erroneous inconsistent regulation auer supra internal quotation marks omitted mensing demahy suggest reason doubt agency reading therefore conclude cbe process open manufacturers sort change required state law next mensing demahy contend manufacturers used dear doctor letters send warnings prescribing physicians healthcare professionals see brief respondents cfr fda disagrees defer agency views fda argues dear doctor letters qualify labeling brief see also cfr thus letters must consistent contrary drug approved labeling cfr dear doctor letter contained substantial new warning information consistent drug approved labeling moreover generic drug manufacturers manufacturer sent letters inaccurately imply therapeutic difference brand generic drugs thus impermissibly misleading brief see cfr fda may withdraw approval generic drug labeling drug false misleading particular cbe regulation defer fda mensing demahy offer argument fda interpretation plainly erroneous see auer accordingly conclude federal law permit manufacturers issue additional warnings dear doctor letters though fda denies manufacturers used cbe process dear doctor letters strengthen warning labels agency asserts different avenue existed changing generic drug labels according fda manufacturers proposed indeed required propose stronger warning labels agency believed warnings needed brief fed reg fda agreed label change necessary worked manufacturer create new label generic drug ibid agency traces duty provides drug misbranded nless labeling bears adequate warnings unsafe dosage methods duration administration application manner form necessary protection users see brief regulation fda interpreted statute require labeling shall revised include warning soon reasonable evidence association serious hazard drug cfr according fda requirements apply drugs explains premise federal drug regulation manufacturer bears responsibility content label times brief quoting wyeth fda reconciles duty adequate accurate labeling duty sameness following way generic drug manufacturers become aware safety problems must ask agency work toward strengthening label applies generic equivalent drug brief manufacturers fda disagree whether alleged duty request strengthened label actually existed fda argues explained duty preamble regulations implementing amendments ibid see fed reg generic drug manufacturer believes new safety information added product labeling contact fda fda determine whether labeling generic listed drugs revised manufacturers claim fda statement create duty generic drug manufacturer ever acting pursuant duty see tr oral arg reply brief petitioner pliva et al ultimately find even assuming duty existed resolve matter summarize relevant state federal requirements state tort law places duty directly drug manufacturers adequately safely label products taking mensing demahy allegations true duty required manufacturers use different stronger label label actually used federal drug regulations interpreted fda prevented manufacturers independently changing generic drugs safety labels assume federal law also required manufacturers ask fda assistance convincing manufacturer adopt stronger label corresponding generic drug manufacturers well turn question iii supremacy clause establishes federal law shall law land thing constitution laws state contrary notwithstanding art vi cl state federal law directly conflict state law must give way wyeth supra thomas concurring judgment see also crosby national foreign trade council tate law naturally preempted extent conflict federal statute held state federal law conflict impossible private party comply state federal requirements freightliner myrick internal quotation marks omitted find impossibility lawful federal law manufacturers state law required even fulfilled federal duty ask fda assistance satisfied requirements state law manufacturers independently changed labels satisfy duty violated federal law taking mensing demahy allegations true state law imposed duty attach safer label generic metoclopramide federal law however demanded drug labels times drug labels see cfr thus impossible manufacturers comply duty change label federal law duty keep label federal duty ask fda help strengthening corresponding label assuming duty exists change analysis although requesting fda assistance satisfied federal duty satisfied state duty provide adequate labeling state law demanded safer label instruct manufacturers communicate fda possibility safer label indeed mensing demahy deny state tort claims based manufacturers alleged failure ask fda assistance changing labels brief respondents cf buckman plaintiffs legal holding federal drug medical device laws state claim based failure properly communicate fda mensing demahy contend claims turn whether manufacturers asked fda assistance changing labels manufacturers federal affirmative defense mensing demahy argue manufacturers asked fda help changing corresponding label might eventually able accomplish federal law state law requires true enough manufacturers freely concede asked fda help pliva brief done fda decided sufficient supporting information fda undertook negotiations manufacturer adequate label changes decided implemented manufacturers started mouse trap game eventually led better label generic metoclopramide raises novel question whether conflict take account possible actions fda manufacturer federal law permitted manufacturers changed even absent change law depending actions fda manufacturer federal law dictate text generic drug label rather ties labels counterparts thus federal law permit manufacturers comply state labeling requirements fda manufacturer changed label mensing demahy assert private party ability comply state law depends approval assistance fda proving requires party demonstrate fda allowed compliance state law argue manufacturers bear burden proving impossibility even try start process might ultimately allowed use safer label brief respondents fair argument reject question impossibility whether private party independently federal law state law requires see wyeth finding defendant unilaterally state law required accepting mensing demahy argument render conflict largely meaningless make conflicts state federal law illusory often imagine third party federal government might something makes lawful private party accomplish federal law state law requires cases certainly possible manufacturers asked fda help might eventually able strengthen warning label course also possible manufacturers convinced fda reinterpret regulations manner opened cbe process following mensing demahy argument logical conclusion also possible asking manufacturers persuaded fda rewrite generic drug regulations entirely talked congress amending amendments conjectures suffice prevent federal state law conflicting supremacy clause purposes unclear outside express supremacy clause read supremacy clause permit approach renders conflict meaningless supremacy clause face makes federal law law land even absent express statement congress art vi cl moreover text clause federal law shall thing constitution laws state contrary notwithstanding plainly contemplates conflict describing federal law effectively repealing contrary state law ibid see nelson preemption rev describing discussion supremacy clause state ratification debates concerning whether federal law repeal state law vice versa phrase state law contrary notwithstanding non provision nn legislatures used non obstante provisions specify degree new statute meant repeal older potentially conflicting statutes field citing dozens statutes similar provisions non obstante provision new statute acknowledged statute might contradict prior law instructed courts apply general presumption implied repeals bacon new abridgment law ed although two acts parliament seemingly repugnant yet clause non obstante latter shall possible construction latter may repeal former implication non obstante provision supremacy clause therefore suggests federal law understood impliedly repeal conflicting state law provision suggests courts strain find ways reconcile federal law seemingly conflicting state law traditionally courts went great lengths attempting harmonize conflicting statutes order avoid implied repeals warder arell opinion roane seek construction reconcile statutes together ludlow heirs johnston ohio fair course reasoning two statutes reconciled shall stand doolittle bryan requiring repugnance quite plain finding implied repeal non obstante provision thus useful way legislatures specify want courts distorting new law accommodate old nelson supra see also sutherland statutes statutory construction hen inserted statute provision non obstante supposed courts less inclined recognizing repugnancy applying statutes weston case eng hen two statutes one appearance crossing clause non obstante contained second statute exposition stand force jacob new law dictionary morgan ed definition statute hen seeming variance two statutes clause non obstante latter construction shall made may stand non obstante provision supremacy clause indicates need look ordinary meanin federal law distort federal law accommodate conflicting state law wyeth thomas concurring judgment internal quotation marks omitted consider analysis contingencies inherent cases manufacturers ability comply state law depended uncertain federal agency decisions inconsistent non obstante provision supremacy clause manufacturers required continually prove counterfactual conduct fda manufacturer order establish supremacy federal law think supremacy clause contemplates sort contingent supremacy non obstante provision suggests analysis involve speculation ways federal agency actions potentially reconcile federal duties conflicting state duties ordinary meaning federal law blocks private party independently accomplishing state law requires party established sure whether private party act sufficiently independently federal law state law requires may sometimes difficult determine case manufacturers satisfy state law fda federal agency undertake special effort permitting decide cases enough hold party satisfy state duties without federal government special permission assistance dependent exercise judgment federal agency party independently satisfy state duties purposes state law imposed duty manufacturers take certain action federal law barred taking action action manufacturers independently take asking fda help matter concern mensing demahy tort claims wyeth contrary case plaintiff contended drug manufacturer breached state duty provide adequate warning label held lawsuit possible wyeth drug manufacturer comply state federal law specifically cbe regulation cfr iii permitted drug manufacturer like wyeth unilaterally strengthen warning without prior fda approval cf supra thus federal regulations applicable wyeth allowed company volition strengthen label compliance state tort recognize perspective mensing demahy finding wyeth makes little sense mensing demahy taken reglan drug prescribed doctors wyeth control lawsuits pharmacists acting full accord state law substituted generic metoclopramide instead federal law lawsuits see stat describing pharmacists may substitute drugs la rev stat ann west acknowledge unfortunate hand federal drug regulation dealt mensing demahy others similarly task decide whether statutory scheme established congress unusual even bizarre cuomo clearing house thomas concurring part dissenting part slip internal quotation marks brackets omitted beyond dispute federal statutes regulations apply drug manufacturers meaningfully different apply generic drug manufacturers indeed special different regulation generic drugs allowed generic drug market expand bringing drugs quickly cheaply public different federal statutes regulations may lead different results distort supremacy clause order create similar across dissimilar statutory scheme always congress fda retain authority change law regulations desire judgments fifth eighth circuits reversed cases remanded proceedings consistent opinion ordered pliva et petitioners gladys mensing actavis elizabeth llc petitioner gladys mensing actavis petitioner julie demahy writs certiorari courts appeals eighth fifth circuits june justice sotomayor justice ginsburg justice breyer justice kagan join dissenting today invokes doctrine impossibility hold federal law immunizes manufacturers claims unilaterally change agree traditionally held defendants claiming impossibility demanding standard today mere possibility impossibility enough establish food drug administration fda permits assumes requires manufacturers propose label change fda believe labels inadequate agrees labels inadequate fda initiate change label triggering corresponding change generic labels occurs generic manufacturer full compliance federal law duty warn although generic manufacturers may able show impossibility cases petitioners generic manufacturers metoclopramide manufacturers shown might unable comply federal law duties warn respondents gladys mensing julie demahy hold insufficient sustain burden strains reach opposite conclusion invents new principles law thin air justify dilution impossibility standard effectively rewrites decision wyeth levine holds federal law claims drug manufacturers plurality tosses aside repeated admonition courts hesitate conclude congress intended state laws governing health safety result today decision whether consumer harmed inadequate warnings obtain relief turns solely happenstance whether pharmacist filled prescription generic drug gets one thing right outcome makes little sense ante today decision affects percent prescription drugs dispensed country dominant position generic drugs prescription drug market result series legislative measures federal state congress enacted drug price competition patent term restoration act stat commonly known amendments federal food drug cosmetic act fdca make available low cost generic drugs establishing generic drug approval procedure pt majority explains accomplish goal amendments establish abbreviated application process generic drugs ante see also abbreviated approval process implements amendments core principle generic drugs must nearly respects obtain fda approval generic manufacturer must ordinarily show among things product active ingredients approved drug route dosage form strength new drug drug product bioequivalent drug ii iii iv eliminating need generic manufacturers prove drugs safety efficacy independently amendments allow generic manufacturers bring drugs market much less expensively also acted expand consumption generic drugs years leading passage amendments enacted legislation authorizing pharmacists substitute generic drugs filling prescriptions drugs christensen kirking ascione welage gaither drug product selection legal issues pharmaceutical assn currently form generic substitution law see ibid require generic substitution certain circumstances dept health human aspe issue brief expanding use generic drugs hereinafter expanding use generic drugs see educ law ann west others permit require substitution expanding use generic drugs see cal bus code ann west supp require patient consent substitution allow physician specify brand name must prescribed although different levels effort physician expanding use generic drugs legislative efforts expand production consumption generic drugs proved wildly successful estimated amendments enacted generic drugs constituted percent drugs sold country congressional office increased competition generic drugs affected prices returns pharmaceutical industry today dominate market see expanding use generic drugs generic drugs constituted percent dispensed prescription drugs ninety percent drugs generic version available filled generics many cases generic versions drug enter market manufacturer stops selling drug altogether see brief marc law et al amici curiae citing studies showing anywhere generic drugs longer marketed equivalent reflecting success products many generic manufacturers including manufacturers amici huge multinational companies total generic drug manufacturers sold estimated billion drugs country see noted obtain fda approval generic manufacturer must generally show drug approved drug need conduct clinical trials prove safety efficacy drug mean however generic manufacturer duty federal law ensure safety products fda limited resources conduct postapproval monitoring drug safety see wyeth manufacturers recognized superior access information drugs especially postmarketing phase new risks emerge federal law thus obliges drug manufacturers generic monitor safety products federal law generic manufacturers must develop written procedures surveillance receipt evaluation reporting postmarketing adverse drug experiences cfr see also making applicable generic manufacturers brief amicus curiae hereinafter brief must review reports adverse drug experiences received source manufacturer receives report serious unexpected adverse drug experience must event fda within days must promptly investigate ii see also tr oral arg adverse drug experiences must reported quarterly yearly generic manufacturers must also submit fda annual report summarizing significant new information previous year might affect safety labeling drug product including description actions manufacturer taken intends take result new information see also generic manufacturers majority assumes also bear responsibility federal law monitoring adequacy warnings agree majority conclusion generic manufacturers permitted unilaterally change labels cbe process issue additional warnings dear doctor letters see ante according fda however generic manufacturers disseminate additional warnings mean federal law permits remain idle conclude labeling inadequate fda regulations require labeling revised include warning soon reasonable evidence association serious hazard drug cfr currently codified cfr see also wyeth fda construes regulation oblige generic manufacturers seek revise labeling provide fda supporting information risks believe additional warnings brief manufacturers disagree read fda regulation require ensure labels match labels see brief petitioner pliva et al need decide whether regulation fact obliges generic manufacturers approach fda propose label change majority assumes even generic manufacturers duty propose label changes two points remain undisputed first duty federal law monitor safety products second may approach fda propose label change believe change required ii brings manufacturers defense state law obliged manufacturers warn dangers users see hines remington arms la frey montgomery ward manufacturers contend majority agrees federal law respondents claims federal law provided additional warnings respondents without exercise judgment fda endorse novel conception impossibility two principles guide analysis first purpose congress ultimate touchstone every case wyeth quoting medtronic lohr second cases particularly congress legislated field traditionally occupied start assumption historic police powers superseded federal act unless clear manifest purpose congress wyeth quoting lohr internal quotation marks omitted alterations original principles find particular resonance cases traditionally regulated health safety matters see notwithstanding congress certain awareness prevalence state tort litigation drug manufacturers wyeth congress expressly tort actions prescription drug manufacturers whether generic contrary congress amended fdca enlarg fda powers public health safety effectiveness reliability drugs took care preserve state law quoting stat see pub stat nothing amendments made act fdca shall construed invalidating provision state law valid absence amendments unless direct positive conflict amendments provision state law notably although congress enacted express provision medical devices see pub stat included provision amendments eight years later cf wyeth congress silence issue powerful evidence intend fda oversight exclusive means ensuring drug safety effectiveness federal law impliedly state law state federal law conflict impossible private party comply state federal law state law stands obstacle accomplishment execution full purposes objectives congress crosby national foreign trade council internal quotation marks omitted manufacturers rely solely former ground impossibility emphasized defense wyeth affirmative defense defendant seeking set aside state law bears burden prove impossibility see ibid silkwood prevail defense defendant must demonstrate compliance federal state law physical impossibility florida lime avocado growers paul see also wyeth words must inevitable collision federal state law florida lime existence hypothetical potential conflict insufficient warrant state law rice norman williams see also gade national solid wastes management kennedy concurring part concurring judgment words mere possibility impossibility enough manufacturers contend impossible provide additional warnings respondents demahy federal law prohibited changing labels concede however asked fda initiate label change fda agreed label change required asked indeed pressured manufacturer change label triggering corresponding change manufacturers generic thus manufacturers invoked available mechanism initiating label changes may well able change labels sufficient time warn respondents failed manufacturers sustain burden least without factual development demonstrate impossible comply federal state law demonstrated hypothetical potential conflict rice like majority manufacturers focus fact change labels unilaterally distinguishes defendant wyeth correctly point wyeth concluded fda cbe regulation authorized defendant strengthen warnings receiving agency approval supplemental application describing label change see also cfr defendant label change contingent fda acceptance fda retained authority reject labeling changes made pursuant cbe regulation wyeth thus long run manufacturer compliance duty warn required action two actors manufacturer change label fda upon reviewing supplemental application agree need fda approval label change make compliance federal state law impossible every case instead defendant bore burden show impossibility required produce clear evidence fda approved change label ibid apply approach cases state law respondents allege required manufacturers provide strengthened warning dangers metoclopramide like manufacturer wyeth manufacturers available mechanism attempting comply duty warn federal law thus accommodated manufacturers duties see ante necessarily impossible manufacturers comply federal state law approached fda fda may well agreed label change necessary accordingly wyeth require manufacturers show fda approved proposed label change made showing argue attempted give kind warning required state law prohibited fda wyeth say generic manufacturers never show impossibility defendant proposed label change fda fda rejected proposal impossible defendant comply duty warn likewise impossibility established fda yet responded generic manufacturer request label change time plaintiff injuries arose generic manufacturer might also show fda considered whether request enhanced warnings light evidence plaintiff claim rests decided leave warnings manufacturers make argument cases see brief petitioner actavis et al questions fact established discovery burden proving impossibility falls defendant hold federal law render impossible generic manufacturers comply duty warn categorical matter conclusion flows naturally overarching governing doctrine see supra respect sovereigns federal system leads us assume cavalierly causes action wyeth quoting lohr reason hold defendants asserting impossibility demanding standard wyeth presumption particular force federal government afforded defendants mechanism complying state law even mechanism requires federal agency action presumption even greater force federal law requires defendants invoke mechanism majority assumes cases circumstances hold defendants usually unable sustain burden showing impossibility even attempted employ mechanism approach threatens infringe authority traditional matters state interest claims congress expressed intent state law majority concedes manufacturers might able accomplish federal law state law requires ante reach conclusion manufacturers nonetheless satisfied show impossibility majority invents new rule question whether private party independently federal law state law requires ante emphasis added manufacturers changed labels without exercise judgment fda majority holds compliance state federal law impossible majority new test basis precedents majority cites wyeth support test discussed however wyeth stand proposition impossible comply federal state law whenever federal agency approval required contrary label changes manufacturers wyeth subject fda review acceptance see supra even wyeth characterized turning fact manufacturer change label unilaterally possibility unilateral action sufficient condition rejecting impossibility defense case wyeth hold unilateral action necessary condition every case little support case law majority turns rationales none rationales offers however makes sense first offers reductio ad absurdum possibility fda approval label change sufficient avoid conflict cases warns logical conclusion possibility fda might rewrite regulations congress might amend amendments ante logic conclusion escapes conflict analysis necessarily turns existing law thus ridiculous conclude federal state law conflict ground defendant asked federal agency congress change law contrast manufacturers compliance duty warn ask change federal law majority recognizes see ante ederal law permit manufacturers comply state labeling requirements fda manufacturer changed label fda already afforded mechanism attempting comply duties indeed majority assumes fda regulations required manufacturers request label change reasonable evidence association serious hazard drug cfr second majority suggests approach render conflict illusory ante expresses concern without robust view constitutes conflict supremacy clause force except cases express ibid extent majority purported concern driven reductio ad absurdum see ante concern illusory reasons stated extent majority concerned traditionally narrow view constitutes impossibility somehow renders conflict whole meaningless concern simply makes sense repeatedly recognized conflict may found even absent impossibility state law stands obstacle accomplishment execution full purposes objectives congress crosby internal quotation marks omitted see geier american honda motor barnett bank marion nelson hines davidowitz majority expansive view impossibility thus unnecessary prevent conflict losing third plurality adopts novel theory framers intended supremacy clause operate non obstante provision see ante citing nelson preemption rev according plurality non obstante provisions statutes instruc courts apply general presumption implied repeals ante internal quotation marks omitted see also ante stating statute contains non obstante provision less inclined recognizing repugnancy applying quoting sutherland statutes statutory construction understanding supremacy clause plurality extrapolates principle courts strain find ways reconcile federal law seemingly conflicting state law ante principle news congress enacted amendments precedents hold opposite half century directed courts presume congressional action supersede historic police powers unless clear manifest purpose congress rice santa fe elevator see also gade kennedy concurring part concurring judgment apply presumption congress spoken question see wyeth context express read federal statutes whenever possible state law see altria group good hen text clause susceptible one plausible reading courts ordinarily reading disfavors quoting bates dow agrosciences llc see also cipollone liggett group claim federal law impliedly state law require strong showing conflict overcome presumption state local regulation constitutionally coexist federal regulation hillsborough county automated medical laboratories plurality new theory supremacy clause direct assault whereas long presumed federal law repeal state law plurality today reads supremacy clause operate provision instructing courts apply general presumption implied repeals ante internal quotation marks omitted emphasis added whereas long required evidence clear manifest purpose rice plurality instructs courts look ordinary meaning federal law concluding congress must intended cast aside state law ante internal quotation marks alteration omitted plurality finds necessary resort novel theory supremacy clause theory advocated party amici cases telling proper application longstanding presumption compels conclusion federal law render compliance state law impossible merely requires actor seek federal agency approval federal law provides actors attempting comply duties respect sovereigns federal require actors attempt comply state law heard complain compliance laws impossible wyeth quoting lohr iii today decision leads many absurd consequences fathom congress intended state law cases first majority analysis strips consumers compensation injured inadequate warnings congress intended deprive injured parties long available form compensation surely expressed intent clearly bates given longstanding existence product liability actions including failure warn difficult believe congress without comment remove means judicial recourse injured illegal conduct silkwood see also bruesewitz wyeth llc slip noting previously expressed doubt congress quietly preempt claims without providing federal substitute concluding congress silently immunized generic manufacturers claims majority disregards previous hesitance infer congressional intent effect sweeping change traditional remedies majority admits drug consumer right compensation inadequate warnings turns happenstance whether pharmacist filled drug generic consumer takes drug sue manufacturer inadequate warnings opinion wyeth however takes generic drug occurs percent time right sue majority offers reason think apart new articulation impossibility standard congress intended arbitrary distinction pharmacists must dispense generic drugs absent instruction contrary consumer physician even consumers request drugs price drug consumers insurance plans may make impossible result many cases consumers ability preserve right recover injuries caused inadequate warnings second majority decision creates gap parallel regulatory scheme way troubling consequences drug safety explained wyeth tate tort suits uncover unknown drug hazards provide incentives drug manufacturers disclose safety risks promptly thus recognized state law offers additional important layer consumer protection complements fda regulation ibid today decision eliminates traditional incentives generic manufacturers monitor disclose safety risks generic drug equivalent market manufacturer remain incentivized uncover safety risks manufacturers often leave market generic versions available see supra meaning manufacturer subject liability generic drugs additional layer consumer protection wyeth finally today decision undoes core principle amendments generic drugs nearly see brief henry waxman amicus curiae majority pins expansion generic drug market special different regulation generic drugs allows generic manufacturers produce drugs cheaply ante tells half story expansion market generic drugs also flowed increased acceptance trust generic drugs consumers physicians state legislators alike today decision introduces critical distinction generic drugs consumers drugs sue manufacturers inadequate warnings consumers generic drugs divergent liability rules threaten reduce consumer demand generics least among consumers afford drugs may pose ethical dilemma prescribing physicians brief american medical association et al amici curiae may well cause rethink longstanding efforts promote generic use generic substitution laws see brief national conference state legislators amicus curiae state generic substitution laws proceeded premise generic drugs citizens perspective materially different brand ones except lower price consequences directly odds amendments goal increasing consumption generic drugs nothing opinion convinces enacting requirement generic labels match corresponding labels congress intended absurd results certainly shown clear manifest purpose congress wyeth internal quotation marks omitted emphasis added contrary federal law affords generic manufacturers mechanism attempting comply duties warn hold federal law categorically claims generic manufacturers especially light presumption burden fall generic manufacturers show compliance impossible particular facts case holding possibility possibility insufficient defea cases ante contorts doctrine exempts defendants burden establish impossibility respect dissent footnotes together actavis elizabeth llc mensing also certiorari actavis demahy certiorari appeals fifth circuit footnotes justice kennedy joins part opinion relevant events cases predate food drug administration amendments act stat therefore refer exclusively statutes regulations express view impact act use generic drug refers drug designed copy reference listed drug typically drug thus identical active ingredients safety efficacy see generix drug cfr defining reference listed drug brief filed represents views fda cf talk america michigan bell telephone slip chase bank usa mccoy slip although defer agency interpretation regulations defer agency ultimate conclusion whether state law wyeth levine address whether state federal law directly conflict circumstances beyond impossibility see wyeth thomas concurring judgment suggesting might amendments contain provision expressly state tort claims see post sotomayor dissenting contain saving clause expressly preserve state tort claims cf williamson mazda motor america thomas concurring judgment discussing saving clause national traffic motor vehicle safety act although express statement always preferable lack statement end inquiry contrary dissent suggestion absence express reason find conflict see post dissent asserts forgetting post dissent acknowledges form conflict post conflict analysis must take account hypothetical federal action including possible changes acts congress little reason think based purposes objectives congress survive either wyeth also urged state tort law creat ed unacceptable accomplishment execution full purposes objectives congress quoting hines davidowitz rejected argument type argued cf post opinion sotomayor fda however retained authority eventually rescind wyeth unilateral cbe changes accordingly noted wyeth attempted show clear evidence fda rescinded change label thereby demonstrate fact impossible federal law state law required wyeth supra wyeth offered evidence analysis consistent holding today wyeth asked drug manufacturer independently federal law absence clear evidence wyeth accomplished state law required found wyeth held federal law accommodated state law duties possibility impossibility enough post see also rice norman williams rejecting hypothetical impossibility existing federal law directly conflicts state law post conflict analysis necessarily turns existing law question cases whether possibility impossibility establishes rather whether possibility possibility defeats post said dissent overstates characterizes many absurd consequences holding post first fda us practical matter genuinely new information drugs long use generic drugs typically appears brief patent protections ordinarily prevent generic drugs arriving market number years drug appears indeed situations like one alleged apparently rare fda formal regulation establishing generic drug manufacturers duty initiate label change regulation setting process second dissent admits even approach generic drug manufacturers establish number scenarios post footnotes online http internet materials visited june available clerk case file addition many insurance plans structured promote generic use see congressional budget office effects using generic drugs medicare prescription drug spending online http state medicaid programs similarly promote generic use see kaiser medicaid uninsured state medicaid outpatient prescription drug policies findings national survey update online online http adverse drug experience defined ny adverse event associated use drug humans whether considered drug related cfr like majority refer statutes regulations see ante congressional hearings amendments representatives generic drug manufacturers confirmed obligation ability conduct postapproval investigation adverse drug experiences see drug legislation hearings et al subcommittee health environment house committee energy commerce statement kenneth larsen chairman generic pharmaceutical industry association gpha generic manufacturers sensitive importance looking adverse reactions provide whatever required performed meet regulatory requirement provide safety using drug role responsibility obligation business statement bill haddad executive officer president gpha every single generic drug company know large research staff researches drug copying bringing market researches new drugs researches adverse reaction fda construction regulation mirrors guidance provided generic manufacturers nearly years ago announcing final rule implementing abbreviated application process generic drugs anda application approval generic drug applicant believes new safety information added product labeling contact fda fda determine whether labeling generic listed drugs revised approval anda anda holder believes new safety information added provide adequate supporting information fda fda determine whether labeling generic listed drugs revised fed reg fda internal procedures recognize office generic drugs consult fda components labeling reviews manual policies procedures may consultations involving possible serious safety concerns receive highest priority decision eighth circuit suggested manufacturers show impossibility federal law merely permitted sell generic drugs require see mensing wyeth generic defendants compelled market metoclopramide realized label insufficient believe even propose label change simply stopped selling product see also geier american honda motor describing case impossibility one state law penalizes federal law requires emphasis added respondents advanced argument find unnecessary consider time respondents cause action arose fda authority require manufacturer change label received authority see pub stat supp iii equally significant authority withdraw manufacturer permission market drug manufacturer refused make requested labeling change see ed cfr manufacturer ability comply duty warn depend unilateral actions period changed label fda approved disapproved label change claim wyeth appear arisen period respondents claim manufacturers required ask fda assistance changing labels role fda arises result manufacturers defense cases involve situation manufacturer produces generic drugs see okie multinational medicines ensuring drug quality era global eng med see also gpha frequently asked questions generics http companies make half generic drugs case manufacturer independently change label cbe regulation triggering corresponding change generic label justice thomas author today opinion previously expressed view obstacle inconsistent constitution see williamson mazda motor america opinion concurring judgment slip wyeth levine opinion concurring judgment position however accepted thus justify majority novel expansion impossibility author law review article proposing theory supremacy clause acknowledges much see nelson preemption rev non obstante provision rejects artificial presumption congress intend contradict state laws federal statutes must therefore harmonized state law plurality hand carefully avoids discussing ramifications new theory longstanding presumption according gpha fda generic drug industry spend millions dollars year seeking reassure consumers affordable generic drugs really federal law compels pricier counterparts brief gpha amicus curiae pet cert nos pp