Full opinion text
Opinion MOSK, Acting C. J. In this case we address the question whether a plaintiff alleging injury from ingesting a prescription drug can state a claim against the manufacturer for strict liability and breach of warranty for failure to warn about the known or reasonably scientifically knowable dangerous propensities of its product. We conclude that she can. In our recent decision in Anderson v. Owens-Corning Fiberglas Corp. (1993) 53 Cal.3d 987 [281 Cal.Rptr. 528, 810 P.2d 549] (hereafter Anderson), we held generally that manufacturers are strictly liable for injuries caused by their failure to give warning of dangers that were known to the scientific community at the time they manufactured and distributed the product: “Whatever may be reasonable from the point of view of the manufacturer, the user of the product must be given the option either to refrain from using the product at all or to use it in such a way as to minimize the degree of danger.” (Id. at p. 1003.) In so doing, we expressly applied to manufacturers of all products the same rule of strict liability for failure to warn of known or reasonably scientifically knowable risks that we previously applied specifically to manufacturers of prescription drugs. (Id. at p. 1000; see Brown v. Superior Court (1988) 44 Cal.3d 1049 [245 Cal.Rptr. 412, 751 P.2d 470] (hereafter Brown.) The Upjohn Company (hereafter Upjohn), a manufacturer of prescription drugs, urges us to now reject the strict liability standard under Anderson for cases involving failure to warn of known or reasonably scientifically knowable risks from prescription drugs, and adopt a new standard of simple negligence for that industry only. We discern no sound basis for doing so. Accordingly, we affirm the judgment of the Court of Appeal. I. Plaintiff Wilma Peggy Carlin (hereafter Carlin) brought an action for damages against Upjohn for injuries she assertedly sustained from ingesting the drug Halcion, which was prescribed for her by a physician between 1987 and 1992. She claimed, as relevant here, that Upjohn was strictly liable for failing “properly to prepare and/or warn of the dangerous propensities of Halcion.” She specifically alleged that Upjohn “knew that the drug Halcion was defective ...[,] that those who were prescribed Halcion and took the same would experience, and did experience, severe physical, mental, and emotional damages/injuries and yet, notwithstanding this knowledge, [it] despicably, and in willful and conscious disregard of the safety of those who were prescribed Halcion and of the plaintiff herein, without giving any notice of the defect to the purchasers of Halcion, placed and persisted in placing Halcion into the stream of commerce . . . .” She also claimed that Upjohn was liable for breach of warranty. She alleged that it “expressly and impliedly warranted to the physicians and their health-care patients that Halcion was a prescription drug fit for the use for which it was intended and was of merchantable quality” despite the fact that the product “was unfit and unsafe for ingestion by health-care patients in light of its known propensity to cause serious side-effects, including, but not limited to, physical, mental and emotional injuries to persons ingesting Halcion . . . .” Upjohn demurred, alleging, inter alia, that Carlin failed to state facts sufficient to constitute a cause of action for strict liability or for breach of warranty. It argued that, under California law, no cause of action for strict liability or breach of warranty can be stated against a prescription drug manufacturer based on failure to warn. The superior court sustained the demurrer as to those causes of action without leave to amend. Carlin petitioned for a writ of mandate. The Court of Appeal issued an alternative writ of mandate; after briefing and oral argument, it issued a peremptory writ of mandate, directing the superior court to vacate its order sustaining the demurrer to the causes of action for strict liability and breach of warranty and to enter a new order overruling the demurrer. We granted review. II. Upjohn contends that the Court of Appeal erred in vacating the superior court’s order sustaining a demurrer on Carlin’s cause of action for strict liability for failure to warn. It argues that California courts have “long refused to expand the scope of potential liability of prescription pharmaceutical manufacturers beyond traditional negligence principles.” Not so. In prior cases, we have expressly and repeatedly applied a strict liability standard to manufacturers of prescription drugs for failure to warn of known or reasonably scientifically knowable risks. We merely reaffirm those precedents here. In Anderson, we summarized prior case law and outlined the general principles of strict liability as they have been applied by California courts for over three decades. (Anderson, supra, 53 Cal.3d at pp. 994-1003.) As we explained therein, under our doctrine of strict liability, first announced in Greenman v. Yuba Power Products, Inc. (1963) 59 Cal.2d 57 [27 Cal.Rptr. 697, 377 P.2d 897, 13 A.L.R.3d 1049], a manufacturer “ ‘is strictly liable in tort when an article he places on the market, knowing that it is to be used without inspection for defects, proves to have a defect that causes injury to a human being.’ . . . ‘The purpose of such liability is to insure that the costs of injuries resulting from defective products are borne by the manufacturers that put such products on the market rather than by the injured persons who are powerless to protect themselves.’ ...[*][] Strict liability, however, was never intended to make the manufacturer or distributor of a product its insurer. ‘From its inception, . . . strict liability has never been, and is not now, absolute liability [*]0 Strict liability has been invoked for three types of defects—manufacturing defects, design defects, and ‘warning defects,’ i.e., inadequate warnings or failures to warn.” (Anderson, supra, 53 Cal.3d at pp. 994-995; see Barker v. Lull Engineering Co. (1978) 20 Cal.3d 413 [143 Cal.Rptr. 225, 573 P.2d 443, 96 A.L.R.3d 1].) We specifically addressed the issue “whether knowledge, actual or constructive, is a component of strict liability on the failure-to-wam theory.” (Anderson, supra, 53 Cal.3d at p. 990.) We concluded that it is. “The California courts, either expressly or by implication, have to date required knowledge, actual or constructive, of potential risk or danger before imposing strict liability for a failure to warn.” (Id. at p. 991.) We affirmed that “California is well settled into the majority view that knowledge or knowability is a component of strict liability for failure to warn.” (Id. at p. 1000.) Although Anderson involved an action against a manufacturer of asbestos, we relied extensively on cases involving a variety of products, including prescription drugs. In particular, we were guided by our prior decision in Brown, supra, 44 Cal.3d 1049, in which we refused to extend strict liability to the failure to warn of risks that were unknown or unknowable at the time of distribution. “As we stated [in Brown], if a manufacturer could not count on limiting its liability to risks that were known or knowable at the time of manufacture or distribution, it would be discouraged from developing new and improved products for fear that later significant advances in scientific knowledge would increase its liability. . . . [A] manufacturer is not strictly liable for injuries caused by a prescription drug so long as it was properly prepared and accompanied by warnings of its dangerous propensities that were either known or scientifically knowable at the time of distribution.” (Anderson, supra, 53 Cal.3d at p. 999.) We concluded that the holding in Brown applied to all products, not only to prescription drugs: “Brown’s logic and common sense are not limited to drugs. In recognizing the extent to which the majority rule pervades California precedents in both drug and nondrug cases, Brown clearly implied that knowledge is also a component of strict liability for failure to warn in cases other than prescription drug cases.” (Id. at p. 1000; see also Vermeulen v. Superior Court (1988) 204 Cal.App.3d 1192, 1206 [251 Cal.Rptr. 805] [“We . . . do not interpret Brown’s analysis of the failure to warn issue to necessarily be limited to prescription drug cases. The same rationale applies equally to other products.”].) We recognized that the knowledge or knowability requirement for failure to warn infuses some negligence concepts into strict liability cases. (Anderson, supra, 53 Cal.3d at p. 1001.) Indeed, in the failure-to-wam context, strict liability is to some extent a hybrid of traditional strict liability and negligence doctrine. As we explained, however, “the claim that a particular component ‘rings of or ‘sounds in’ negligence has not precluded its acceptance in the context of strict liability.” (Ibid.) Indeed, “the strict liability doctrine has incorporated some well-settled mies from the law of negligence and has survived judicial challenges asserting that such incorporation violates the fundamental principles of the doctrine.” (Id. at p. 1002.) Thus, although Anderson, following Brown, incorporated certain negligence concepts into the standard of strict liability for failure to warn, it did not thereby adopt a simple negligence test. “[Fjailure to warn in strict liability differs markedly from failure to warn in the negligence context. Negligence law in a failure-to-wam case requires a plaintiff to prove that a manufacturer or distributor did not warn of a particular risk for reasons which fell below the acceptable standard of care, i.e., what a reasonably pmdent manufacturer would have known and warned about. Strict liability is not concerned with the standard of due care or the reasonableness of a manufacturer’s conduct. The mies of strict liability require a plaintiff to prove only that the defendant did not adequately warn of a particular risk that was known or knowable in light of the generally recognized and prevailing best scientific and medical knowledge available at the time of manufacture and distribution. Thus, in strict liability, as opposed to negligence, the reasonableness of the defendant’s failure to warn is immaterial. [‘JD Stated another way, a reasonably pmdent manufacturer might reasonably decide that the risk of harm was such as not to require a warning as, for example, if the manufacturer’s own testing showed a result contrary to that of others in the scientific community. Such a manufacturer might escape liability under negligence principles. In contrast, under strict liability principles the manufacturer has no such leeway; the manufacturer is liable if it failed to give warning of dangers that were known to the scientific community at the time it manufactured or distributed the product.” (Anderson, supra, 53 Cal.3d at pp. 1002-1003, fn. omitted.) Similarly, a manufacturer could not escape liability under strict liability principles merely because its failure to warn of a known or reasonably scientifically knowable risk conformed to an industry-wide practice of failing to provide warnings that constituted the standard of reasonable care. We explained the policy behind our strict liability standard for failure to warn as follows: “ ‘When, in a particular case, the risk qualitatively (e.g., of death or major disability) as well as quantitatively, on balance with the end sought to be achieved, is such as to call for a true choice judgment, medical or personal, the warning must be given. . . .’ [Citation.] Thus, the fact that a manufacturer acted as a reasonably prudent manufacturer in deciding not to warn, while perhaps absolving the manufacturer of liability under the negligence theory, will not preclude liability under strict liability principles if the trier of fact concludes that, based on the information scientifically available to the manufacturer, the manufacturer’s failure to warn rendered the product unsafe to its users.” (Anderson, supra, 53 Cal.3d at p. 1003, italics added, quoting Davis v. Wyeth Laboratories, Inc. (9th Cir. 1968) 399 F.2d 121, 129-130 [applying strict liability to a manufacturer of prescription drugs].) Upjohn and amici curiae argue that applying Anderson will place manufacturers of prescription drugs in an untenable position because they must comply with regulations set by the Food and Drug Administration (hereafter FDA), which may preclude them from labeling drugs with warnings of certain side effects. They also contend that Anderson would result in overlabeling of pharmaceuticals. Neither claim withstands scrutiny. We are unpersuaded by Upjohn’s argument that a strict liability standard for failure to warn about known or reasonably scientifically knowable risks from prescription drugs is inconsistent with federal regulatory policy. Upjohn concedes that FDA regulations do not expressly preempt common law tort remedies for failure to warn or occupy the entire field of regulation. As numerous courts have concluded, Congress evinced no intention of preempting state tort liability for injuries from prescription drugs. (See, e.g., Feldman v. Lederle Laboratories (1991) 125 N.J. 117, 147 [592 A.2d 1176, 1192] [“[W]e find nothing in the federal scheme to support the assertion that manufacturers of prescription drugs and antibiotics who literally comply with [FDA regulations] must be immune from state tort liability for injuries caused by their products.”]; Abbot by Abbot v. American Cyanamid Co. (4th Cir. 1988) 844 F.2d 1108, 1112 [98 A.L.R.Fed. 107] [federal law does not preempt imposition of state common law liability for failure to warn, despite the fact that labeling, “once approved, cannot be changed without FDA approval.”]; Mazur v. Merck & Co., Inc. (E.D.Pa. 1990) 742 F.Supp. 239, 247 [“[M]ere compliance with an FDA suggestion, or for that matter, regulation or order, does not mean that state tort law becomes irrelevant. . . . [50 . . . State tort law is intended to supplement federal regulation . . . .”]; cf. Medtronic, Inc. v. Lohr (1996) 518 U.S. _, _ [135 L.Ed.2d 700, 725-726, 116 S.Ct. 2240] (plur. opn. of Stevens, J.) [negligence and strict liability claims for failure to warn about risks of a medical device were not preempted by federal regulations].) We disagree with Carlin’s argument, however, that FDA regulations are essentially irrelevant in a common law action for failure to warn. We reiterate that strict liability for failure to warn is not absolute liability. Under Anderson, drug manufacturers are not strictly liable for a risk that was not known or reasonably scientifically knowable. In this context, it is significant that the FDA precludes drug manufacturers from warning about every conceivable adverse reaction; they may warn only if there exists significant medical evidence of a possible health hazard. They are also specifically precluded from warning of adverse reactions when differences of opinion exist within the medical community with regard to potential adverse reactions. (See 21 C.F.R. § 201.57(d) & (e) (1996) [requiring that warnings shall only be of known hazards, not theoretical hazards]; id., § 1.21(c)(1) [prohibiting the inclusion of differing opinions regarding contraindications, precautions, adverse reactions, and other product hazards on drug warning labels].) At the same time, however, they are required to “describe serious adverse reactions and potential safety hazards, limitations in use imposed by them, and steps that should be taken if they occur. The labeling shall be revised to include a warning as soon as there is reasonable evidence of an association of a serious hazard with a drug; a causal relationship need not have been proved.” (Id., § 201.57(e).) In appropriate cases, FDA action or inaction, though not dispositive, may be admissible under Anderson to show whether a risk was known or reasonably scientifically knowable. (Cf. Hatfield v. Sandoz-Wander, Inc. (1984) 124 Ill.App.3d 780, 787 [80 Ill.Dec. 122, 464 N.E.2d 1105, 1109] [evidence of compliance with FDA requirements is admissible as relevant evidence in a strict tort liability case on the issue whether a pharmaceutical manufacturer failed to provide adequate warnings]; Proctor v. Davis (1995) 275 Ill.App.3d 593, 604 [211 Ill.Dec. 831, 656 N.E.2d 23, 29] [accord].) Similarly, a drug manufacturer could present evidence to show that there was no “reasonably scientifically knowable risk” because, at the time of distribution, the cause of the alleged adverse effect was too speculative to have been reasonably attributable to the drug by a scientist conducting state-of-the-art research. Thus, when a plaintiff’s claim is based on an allegation that a particular risk was “reasonably scientifically knowable,” an inquiry may arise as to what a reasonable scientist operating in good faith should have known under the circumstances of the evidence. As we emphasized in Anderson, we do not altogether reject strict liability in the failure-to-wam context—for drugs or any other products—simply because some considerations of reasonableness sounding in negligence may be required. (Anderson, supra, 53 Cal.3d at pp. 1001-1002.) Moreover, in the case of an alleged “known” risk, if state-of-the-art scientific data concerning the alleged risk was fully disclosed to the FDA and it determined, after review, that the pharmaceutical manufacturer was not permitted to warn—e.g., because the data was inconclusive or the risk was too speculative to justify a warning—the manufacturer could present such evidence to show that strict liability cannot apply; the FDA’s conclusion that there was, in effect, no “known risk” is controlling. (See Feldman v. Lederle Laboratories, supra, 125 N.J. at p. 135 [592 A.2d at p. 1185] [“conflict preemption” occurs when compliance with both federal and state requirements is impossible].) We are also unpersuaded by Upjohn’s assertion that applying strict liability to claims of injury for failure to warn will inevitably result in manufacturers inundating consumers with warnings of even speculative risks from prescription drugs. In Finn v. G. D. Searle & Co. (1984) 35 Cal.3d 691, 701 [200 Cal.Rptr. 870, 677 P.2d 1147], we addressed the potential problems of overlabeling: “[E]xperience suggests] that if every report of a possible risk, no matter how speculative, conjectural, or tentative, imposed an affirmative duty to give some warning, a manufacturer would be required to inundate physicians indiscriminately with notice of any and every hint of danger, thereby inevitably diluting the force of any specific warning given.” (See Anderson, supra, 53 Cal.3d at p. 1002, citing Finn.) The application of the failure-to-wam theory to pharmaceuticals requires determinations whether available evidence established a causal link between an alleged side effect and a prescription drug, whether any warning should have been given, and, if so, whether the warning was adequate. These are issues of fact involving, inter alia, questions concerning the state of the art, i.e., what was known or reasonably knowable by the application of scientific and medical knowledge available at the time of manufacture and distribution of the prescription drug. They also necessarily involve questions concerning whether the risk, in light of accepted scientific norms, was more than merely speculative or conjectural, or so remote and insignificant as to be negligible. Moreover, in the case of prescription drugs, the duty to warn runs to the physician, not to the patient. (See, e.g., Brown, supra, 44 Cal.3d at pp. 1061-1062; Stevens v. Parke, Davis & Co. (1973) 9 Cal.3d 51, 65 [107 Cal.Rptr. 45, 507 P.2d 653, 94 A.L.R.3d 1059] [“In the case of medical prescriptions, ‘if adequate warning of potential dangers of a drug has been given to doctors, there is no duty by the drug manufacturer to insure that the warning reaches the doctor’s patient for whom the drug is prescribed.”]; but see Davis v. Wyeth Laboratories, Inc., supra, 399 F.2d at p. 131 [exception where prescription drug “was not dispensed as such,” but administered in mass immunization program].) Thus, a pharmaceutical manufacturer may not be required to provide warning of a risk known to the medical community. (See Plenger v. Alza Corp. (1992) 11 Cal.App.4th 349, 362 [13 Cal.Rptr.2d 811] [“We are aware of no authority which requires a manufacturer to warn of a risk which is readily known and apparent to the consumer, in this case the physician.”]; Proctor v. Davis, supra, 275 Ill.App.3d at pp. 605-606 [656 N.E.2d at p. 31] [pharmaceutical manufacturer need not provide warning of risks known to the medical community].) Nor does Upjohn offer any sound public policy rationale for departing from Anderson concerning the liability of manufacturers of prescription drugs for failure to warn of known or reasonably scientifically knowable risks. Thus, we are unpersuaded by the argument, purportedly derived from our reasoning in Brown, that manufacturers of prescription drugs should be exempt from the strict liability duty to warn because they might otherwise refrain from developing and marketing drugs, including “cutting-edge vaccines to combat human immunodeficiency virus (HIV)” and other diseases. Our rationale in Brown, which involved strict liability for design defects, is inapplicable: unlike strict liability for design defects, strict liability for failure to warn does not potentially subject drug manufacturers to liability for flaws in their products that they have not, and could not have, discovered. Drug manufacturers need only warn of risks that are actually known or reasonably scientifically knowable. Upjohn offers no clear or sufficient basis for concluding that research and development will inevitably decrease as a result of imposing strict liability for failure to warn of known or reasonably scientifically knowable risks; indeed, requiring manufacturers to internalize the costs of failing to determine such risks may instead increase the level of research into safe and effective drugs. In any event, we see no reason to depart from our conclusion in Anderson that the manufacturer should bear the costs, in terms of preventable injury or death, of its own failure to provide adequate warnings of known or reasonably scientifically knowable risks. As we observed: “Whatever may be reasonable from the point of view of the manufacturer, the user of the product must be given the option either to refrain from using the product at all or to use it in such a way as to minimize the degree of danger.” (Anderson, supra, 53 Cal.3d at p. 1003.) Although Anderson itself involved a nondrug, asbestos, our conclusion therein applies with equal force to prescription drugs. III. Upjohn also contends that the Court of Appeal erred in vacating the superior court’s order sustaining demurrer on Carlin’s cause of action for breach of warranty. It argues that Brown precludes any such cause of action for breach of warranty against manufacturers of prescription drugs. Not so. In Brown, we held only that “a manufacturer of prescription drugs is not strictly liable for injuries caused by such a defect that is neither known nor knowable at the time the drug is distributedand that, accordingly, an action for breach of warranty for such unknown defect does not lie against drug manufacturers. (Brown, supra, 44 Cal.3d at p. 1072, italics added.) That reasoning is inapplicable here. Like her claim for failure to warn, Carlin’s breach of warranty claim is premised on failure to warn of a known or reasonably scientifically knowable defect. We emphasize, however, that the “consumer expectation” aspect of a breach of warranty action is subject, in the prescription drug context, to the general rule, discussed above, that warnings concerning the drug’s properties are properly directed to the physician rather than the patient. (Brown, supra, 44 Cal.3d at pp. 1061-1062 [“[A] patient’s expectations regarding the effects of [a prescription] drug are those related to him by his physician, to whom the manufacturer directs the warnings regarding the drug’s properties.”].) Thus, for purposes of liability for breach of warranty, ordinarily “it is the prescribing doctor who in reality stands in the shoes of ‘the ordinary consumer.’ ” (Carmichael v. Reitz (1971) 17 Cal.App.3d 958, 989 [95 Cal.Rptr. 381].) IV. For these reasons, we conclude that the Court of Appeal in this case correctly applied Anderson and Brown in directing the superior court to vacate its order sustaining Upjohn’s demurrer to the causes of action for strict liability and breach of warranty. Accordingly, we affirm the judgment of the Court of Appeal. Werdegar, J., Spencer, J., and Vogel (C. S.), J., concurred. In view of our express and extensive reliance in Anderson on our rationale in Brown— which involved only prescription drugs—Justice Baxter’s suggestion that Anderson may not properly be understood as “necessarily” applying to prescription drugs is unfounded. (Dis. opn. of Baxter, J., post, at p. 1155.) Although Anderson involved a manufacturer of asbestos, its holding concerning the application of strict liability in failure-to-wam cases was, on its face, intended to apply generally to manufacturers of all products. To the extent that Justice Baxter purports to find any support in the dissenting opinion in Anderson, he is unpersuasive. The Anderson dissent expressed disagreement with the majority’s conclusion that manufacturers generally should be liable only for failure to warn of known or knowable risks—as opposed to liability for failure to warn of risks regardless of whether they were known or knowable—and argued that such a limited form of strict liability should apply only to drug manufacturers. (Anderson, supra, 53 Cal.3d at pp. 1005-1008, conc. & dis. opn. of Mosk, J.) The majority in Anderson rejected that approach. In so doing, they not only considered, but, in effect, adopted the public policy rationale of Brown with regard to all manufacturers. We found support for the standard we adopted in Brown in the Restatement Second of Torts section 402A, comment k, which appears under the topic of “Strict Liability.” (Rest.2d Torts, § 402A, com. k, pp. 353-354.) We noted in Brown that imposing liability only if the manufacturer knew or should have known of a defect “sets forth a test which sounds in negligence.” (Brown, supra, 44 Cal.3d at p. 1059, fn. 4.) We did not, as Upjohn erroneously contends, thereby establish that the standard for failure to warn is simple negligence. Rather, as Anderson explains, we merely rejected a standard of liability that, by imposing liability for unknown and unknowable risks, would be tantamount to “absolute liability.” In Anderson, we explained that our definition of constructive knowledge—i.e., what is “reasonably scientifically knowable”—is derived from the Restatement Second of Torts section 402A, comment j, page 353, which refers to knowledge obtainable “ ‘by the application of reasonable, developed human skill and foresight.’ ” (Anderson, supra, 53 Cal.3d at p. 1002, fn. 13; see Brown, supra, 44 Cal.3d at p. 1069.) The actual knowledge of the individual manufacturer, even if reasonably prudent, is not the issue. We view the standard to require that the manufacturer is held to the knowledge and skill of an expert in the field; it is obliged to keep abreast of any scientific discoveries and is presumed to know the results of all such advances. We also note that both Brown and Anderson require that the knowledge element must exist at the time of distribution. As we explained in Brown, “a manufacturer’s knowledge should be measured at the time a drug is distributed because it is at this point that the manufacturer relinquishes control of the product.” (Brown, supra, 44 Cal.3d at p. 1060, fn. 8.) Obviously, subsequently developed scientific data would not be controlling. We reject the suggestion of the dissenting opinion that the extensive regulation by the FDA of drug labeling should require us to create a new exception to the rule in Anderson unique to drug manufacturers. The fact that the pharmaceutical drug industry is highly regulated does not distinguish it from numerous other industries. Moreover, as the dissenting opinion concedes, the FDA’s approval of a particular warning is not determinative of liability. Nor have our courts adopted the approach of the narrow line of cases cited by the dissenting opinion which would insulate manufacturers for failure to warn if they merely gave FDA-approved warnings. It is a very different thing, however, to hold, as we do here, that a pharmaceutical manufacturer may not be held liable for failing to give a warning it has been expressly precluded by the FDA from giving. Justice Kennard’s concurring and dissenting opinion is simply wrong in asserting that we would impose on prescription drug manufacturers a duty to warn of “every arguable risk.” (Conc. and dis. opn. of Kennard, J., post, at p. 1131.) Justice Kennard also suggests that the costs of tort liability have been “excessive” in the case of such prescription drugs as the vaccines for swine flu, diphtheria-pertussis-tetanus, and polio. (Id. at p. 1127.) Perhaps so. But when a vaccine or other drug poses a severe known risk, albeit to a small proportion of patients, it is unclear how altering the burden of proof for failure to warn as she suggests would reduce those costs—unless the inevitable result would be to deprive an innocent injured person of any remedy. Although Justice Kennard conjectures that physicians “may be overwhelmed by excessive warnings” if manufacturers must warn of known or scientifically knowable risks under this standard (conc. and dis. opn. of Kennard, J., post, at p. 1126), there is no evidence that any such problem has emerged or that patients have suffered any detriment, despite the fact that strict liability has long been the rule in California. We are also unpersuaded by the suggestion of the dissenting opinion that we should create a new exception solely for drug manufacturers because some commentators have suggested in law review articles that the adequacy of warnings is a subset of the question of the acceptability of the basic design of a product. Equally unpersuasive is the dissenting opinion’s suggestion that we should be guided by the fact that some of these same commentators have proposed that the Restatement Third of Torts—which has not been promulgated and, indeed, is still only at the “tentative draft” stage—should adopt a “reasonableness” standard and entirely abandon any standard of strict liability for failure to warn. Both arguments might conceivably support reversing Anderson altogether—an approach that even the dissenting opinion here rejects—but they do not support creating individual exceptions to a general rule of strict liability for failure to warn, e.g., only for drug manufacturers or only for highly regulated industries. Indeed, it would hardly serve to clarify the common law of products liability to create a patchwork of different rules for different types of manufacturers. Since Brown merely concluded that drug manufacturers could not be held strictly liable for failure to warn of unknown and unknowable risks, it did not purport to reject the suitability of warranty claims when a drug posed a known or scientifically knowable health risk. In view of our conclusion that no special exception should be created for drug manufacturers, we discern nothing “mischievous” about permitting plaintiff to pursue her claim for breach of warranty. (See dis. opn. of Baxter, J., post, at p. 1163, fn. 11.) Presiding Justice of the Court of Appeal, Second Appellate District, Division One, assigned by the Acting Chief Justice pursuant to article VI, section 6 of the California Constitution. Presiding Justice of the Court of Appeal, Second Appellate District, Division Four, assigned by the Acting Chief Justice pursuant to article VI, section 6 of the California Constitution.
KENNARD, J., Concurring and Dissenting. The manufacture of prescription drugs, a multibillion-dollar industry, has provided many of the 20th century’s greatest success stories and some of its worst tragedies. Because they cure disease, alleviate pain, and prolong life, prescription drugs have been a great benefit to society. But prescription drugs sometimes cause severe complications and side effects, inflicting great anguish as well as temporary and even permanent disability on some individuals. This court’s task in the present case is to set rules defining prescription drug manufacturers’ tort liability for personal injuries caused by their products’ side effects. More particularly, the task is to determine under what circumstances a drug manufacturer should be held liable in tort for personal injury damages proximately caused by a failure to warn about the possibility of a particular drug complication. The majority holds that a prescription drug manufacturer is liable in tort for all drug-related injuries about which it did not warn, provided only that the risk of injury was either actually known or in some manner scientifically ascertainable by the manufacturer when it distributed the drug. In his dissent, by contrast, Justice Baxter proposes that a prescription drug manufacturer be held liable for failure to warn of possible drug-related injuries only if the person injured by the drug succeeds in proving that the manufacturer’s decision not to warn was unreasonable. I find neither approach entirely satisfactory. Combining what I view as the best features of both, I would hold that initially, to establish a prima facie case, a person seeking damages for drug-related injures on a failure-to-wam theory need prove only that at the time of distribution the manufacturer either knew or should have learned, through the application of commonly accepted scientific methods and reasonably available technologies, of the particular risk of harm; but I would hold also that after the party seeking recovery makes this showing, the manufacturer may defend on the basis that it acted reasonably, in light of all relevant considerations, in not warning of the particular risk. I. What standard of liability should govern when a consumer is injured by a properly manufactured dmg, but the manufacturer has not warned of the dmg’s association with the type of injury suffered? That is the issue here. Because failure-to-wam liability for injuries caused by a dmg is part of the larger field of products liability law, I begin with a discussion of the development and current state of that body of law. Under the common law as it existed before the development of products liability law, an injured consumer could recover only under contractual warranty law, which limited recovery to those who “stood in privity of contract”—that is, the immediate purchasers of the defective product. (Prosser & Keeton on Torts (5th ed. 1984) § 96, p. 681.) All too often, however, consumers lacked such privity because they had bought the product not from the manufacturer directly but from intermediaries such as retailers. Disclaimers of any warranty by the manufacturer erected yet another obstacle to recovery. (Ibid.) The inadequacy of the protection afforded injured consumers under contract law eventually led the courts to extend the existing fault-based tort concept of negligence to the area of products liability. (MacPherson v. Buick Motor Co. (1916) 217 N.Y. 382 [111 N.E. 1050]; see generally, Prosser & Keeton on Torts, supra, § 96, pp. 682-683; Prosser, The Assault Upon the Citadel (Strict Liability to the Consumer) (1960) 69 Yale L.J. 1099, 1100-1103.) Serious impediments to recovery continued to exist, however, even under negligence law. For instance, the injured consumer, because of lack of knowledge about the manufacturing process, was not ordinarily in a position to identify the cause of a defect or to show that the defect had resulted from a manufacturer’s failure to act reasonably. (Prosser, The Assault Upon the Citadel (Strict Liability to the Consumer), supra, 69 Yale L.J. at p. 1116.) To ensure adequate protection to the user of a manufactured product, several legal scholars and jurists, most notably Justice Traynor of this court, adopted the view that a manufacturer should be held liable for defective product injuries regardless of its negligence. (Escola v. Coca Cola Bottling Co. (1944) 24 Cal.2d 453, 462-463, 467 [150 P.2d 436] (conc. opn. of Traynor, J.).) This concept, referred to as products liability or strict liability in tort and extending not only to the manufacturer but to all others in the chain of distribution, ultimately became the law. (Prosser, The Fall of the Citadel (Strict Liability to the Consumer) (1966) 50 Minn. L.Rev. 791, 791-805.) California was the first to embrace this concept when, in 1963, in the landmark case of Greenman v. Yuba Power Products, Inc. (1963) 59 Cal.2d 57 [27 Cal.Rptr. 697, 377 P.2d 897, 13 A.L.R.3d 1049], this court held: “A manufacturer is strictly liable in tort when an article he places on the market, knowing that it is to be used without inspection for defects, proves to have a defect that causes injury to a human being.” (Id. at p. 62; see generally, Prosser, The Fall of the Citadel (Strict Liability to the Consumer), supra, 50 Minn. L.Rev. at pp. 803-805.) As this court has acknowledged, “the very purpose of our pioneering efforts in this field was to relieve the plaintiff from problems of proof inherent in pursuing negligence (Escola v. Coca Cola Bottling Co., supra, 24 Cal.2d 453, 461-462 (Traynor, J. concurring)) and warranty (Greenman v. Yuba Power Products, Inc., supra, 59 Cal.2d 57, 63) remedies, and thereby ‘to insure that the costs of injuries resulting from defective products are borne by the manufacturers . . . (Id; see Price v. Shell Oil Co. [1970] 2 Cal.3d 245, 251 [85 Cal.Rptr. 178, 466 P.2d 722].)” (Cronin v. J.B.E. Olson Corp. (1972) 8 Cal.3d 121, 133 [104 Cal.Rptr. 433, 501 P.2d 1153], ellipses in Cronin.) The concept of products liability then spread nationwide. In 1965, products liability was embraced by the American Law Institute (hereafter ALI) when it adopted section 402A of the Restatement Second of Torts. That section states that a seller of a “product in a defective condition [that is] unreasonably dangerous to the user or consumer” is liable for physical harm caused by the product. (Rest.2d Torts, § 402A, pp. 347-348.) Soon most jurisdictions recognized some form of strict liability for defective products. (Prosser & Keeton on Torts, supra, § 99, p. 694.) Products liability is not absolute liability, however; a manufacturer is not the insurer of the product. (See, e.g., Anderson v. Owens-Corning Fiberglas Corp. (1991) 53 Cal.3d 987, 1003-1004 [281. Cal.Rptr. 528, 810 P.2d 549]; Daly v. General Motors Corp. (1978) 20 Cal.3d 725, 733 [144 Cal.Rptr. 380, 575 P.2d 1162].) A plaintiff must still prove that the product was defective. “Strict liability has been invoked for three types of defects—manufacturing defects, design defects, and ‘warning defects,’ i.e., inadequate warnings or failures to warn.” (Anderson v. Owens-Corning Fiberglas Corp., supra, 53 Cal.3d at p. 995; see Barker v. Lull Engineering Co. (1978) 20 Cal.3d 413 [143 Cal.Rptr. 225, 573 P.2d 443, 96 A.L.R.3d 1].) A manufacturing defect occurs when a product does not conform to the manufacturer’s intended design (Brown v. Superior Court (1988) 44 Cal.3d 1049,1057 [245 Cal.Rptr. 412, 751 P.2d 470]); a design defect occurs either when the design of the product fails to meet consumer expectations as to safety or when, on balance, the risk of danger inherent in the challenged design outweighs the benefits of the design (Soule v. General Motors Corp. (1994) 8 Cal.4th 548, 566-567 [34 Cal.Rptr.2d 607, 882 P.2d 298]); a “warning defect” occurs when a manufacturer has issued no warnings or has failed to adequately warn of dangers posed by the product (see Anderson v. Owens-Corning Fiberglas Corp., supra, 53 Cal.3d at p. 995). The issue here pertains to the third of these categories—liability for a prescription drug manufacturer’s failure to warn. Courts and commentators have long noted that prescription drugs pose unique products liability issues, and that expansive liability for drug-related injuries could deter manufacturers from developing and marketing medical drugs of benefit to society. During the discussion of a draft of what later became section 402A of the Restatement Second of Torts, a member of the ALI proposed that drugs be expressly exempted from section 402A because imposing products liability on drugs might stifle medical research and testing. (Brown v. Superior Court, supra, 44 Cal.3d at pp. 1057-1058, quoting 38 ALI Proc. 19, 90-98 (1961).) In response, Dean Prosser, who was the reporter for the Restatement Second of Torts, suggested that the issue be dealt with in a comment to section 402A. (44 Cal.3d at p. 1058.) This led to the drafting, and approval, of comment k. (See Comment, Comment K Immunity to Strict Liability: Should all Prescription Drugs be Protected? (1989) 26 Hous. L.Rev. 707, 736 [“the beneficial nature of prescription drugs provides the very reason for excepting them from standard rules of strict liability”].) Comment k to section 402A of the Restatement Second of Torts recognizes the significant risk to the public interest presented by imposing excessive liability on the manufacturer of prescription drugs. Under the heading “Unavoidably unsafe products,” comment k observes that commonly used drugs, while highly beneficial, are often incapable of being made entirely safe. It then notes: “It is also true in particular of many new or experimental drugs as to which, because of lack of time and opportunity for sufficient medical experience, there can be no assurance of safety, or perhaps even of purity of ingredients, but such experience as there is justifies the marketing and use of the drug notwithstanding a medically recognizable risk.” (Rest.2d Torts, § 402A, com. k, p. 354.) It concludes that a manufacturer of drugs that are sold with a proper warning “where the situation calls for it, is not to be held to strict liability for unfortunate consequences attending their use, merely because he has undertaken to supply the public with an apparently useful and desirable product, attended with a known but apparently reasonable risk.” (Ibid.) Courts and commentators have debated the exact scope and meaning of comment k to section 402A of the Restatement Second of Torts. (See, e.g., Schwartz, Unavoidably Unsafe Products: Clarifying the Meaning and Policy Behind Comment K (1985) 42 Wash. & Lee L.Rev. 1139 [discussing various possible interpretations of comment k]; Henderson & Twerski, A Proposed Revision of Section 402A of the Restatement (Second) of Torts (1992) 77 Cornell L.Rev. 1512, 1537, 1542 [criticizing comment k for lack of clarity].) This court has concluded that “in fact the principle it [comment k] states is based on negligence.” (Brown v. Superior Court, supra, 44 Cal.3d at p. 1059.) The negligence-based standard of comment k to section 402A of the Restatement Second of Torts reflects a recognition that imposing strict liability on manufacturers of prescription drugs would harm the public interest by discouraging the development and availability of medications that cure diseases, alleviate pain and suffering, or sustain life. In the words of Dean Prosser: “The argument that industries producing potentially dangerous products should make good the harm, distribute it by liability insurance, and add the cost to the price of the product, encounters reason for pause, when we consider that two of the greatest medical boons to the human race, penicillin and cortisone, both have their dangerous side effects, and that drug companies might well have been deterred from producing and selling them.” (Prosser, Torts (4th ed. 1971) § 99, p. 661, fns. omitted.) This concern—not to impose an excessively broad standard of liability on prescription drug manufacturers—continues today. Thus, the current tentative draft of the Restatement Third of Torts contains a special section governing products liability for prescription drugs and medical devices. With regard to warning defects, section 8 provides: “(d) A prescription drug or medical device is not reasonably safe because of inadequate instructions or warnings when [^D (1) reasonable instructions or warnings regarding foreseeable risks of harm posed by the drug or medical device are not provided to prescribing and other health care providers . . . .” (Rest.3d Torts: Products Liability (Tent. Draft No. 2, Mar. 13, 1995) § 8, p. 210.) This court has in recent years addressed liability for “warning defects” for products other than prescription drugs (Anderson v. Owens-Corning Fiberglas Corp., supra, 53 Cal.3d 987 [evidence of whether risk known or knowable admissible in failure-to-wam case not involving prescription drugs]) as well as liability for prescription drug “design defects” (Brown v. Superior Court, supra, 44 Cal.3d 1049 [prescription drug manufacturers exempt from strict liability for design defect claims]). But this court has not previously defined the elements necessary to establish a drug manufacturer’s liability for failure to warn of a risk presented by a prescription drug. To summarize, products or strict liability law was developed to compensate consumers injured by defective products without so expanding liability as to discourage manufacturers from developing and marketing products beneficial to the public. General principles of products liability law appropriately accommodate these competing interests for most types of products. As will be seen, prescription drugs require a standard of liability and a burden-of-proof allocation somewhat different from those used for other products. In this case, neither the majority nor the dissent has adequately accommodated two different consumer interests at stake. II. At first glance, the majority’s holding—that a prescription drug manufacturer need warn only of those risks that are “known or reasonably scientifically knowable” (maj. opn., ante, at p. 1109)—appears quite reasonable. A close look, however, reveals that the majority imposes on a manufacturer a duty to warn of any risk that arguably may exist. The sheer breadth of that duty threatens two fundamental public interests. First, the majority’s holding will result in the problems of overwaming this court has previously recognized, thereby undermining the public interest in consumer protection. Second, by subjecting prescription drug manufacturers to excessive liability, the majority’s standard jeopardizes the important public interest of encouraging the development, availability, and affordability of beneficial prescription drugs. To discern what the majority means by the phrase “known or reasonably scientifically knowable” is no easy task. Throughout its opinion, the majority itself gives different descriptions of the meaning of that phrase (see maj. opn., ante, at p. 1108 [“known to the scientific community”]; id. at p. 1112 [“ ‘generally recognized and prevailing best scientific and medical knowledge available’ ”]; id. at p. 1113, fn. 3 [“knowledge obtainable ‘ “by the application of reasonable, developed human skill and foresight” ’ ”]; ibid. [“ ‘true choice judgment’ ”]; id. at p. 1115 [“reasonable scientist operating in good faith should have known under the circumstances of the evidence”]; id. at p. 1116 [“evidence established a casual link between an alleged side effect and a prescription drug”]; ibid, [“knowable by the application of scientific and medical knowledge available”]). The majority’s various characterizations of “knowability” lead me to conclude that the majority considers a risk to be “knowable,” even though not actually known to the manufacturer, if the risk at the time of distribution had been or reasonably could have been scientifically identified. The word “risk” simply means the possibility of a loss. (Webster’s New Collegiate Dict. (9th ed. 1988) p. 1018, col. 1.) Because the majority does not suggest that the degree of probability of loss is of any significance, the majority seemingly equates the identification of a bare possibility of harm with “knowability” and hence a duty to warn. Thus, under the majority’s holding, once a prescription drug plaintiff proves that a risk has been or reasonably could have been identified by the scientific community, the manufacturer has a duty to warn regardless of whether warning is otherwise appropriate or reasonable. The majority insists that its conclusion is dictated by our decisions in Brown v. Superior Court, supra, 44 Cal.3d 1049, and Anderson v. Owens-Corning Fiberglas Corp., supra, 53 Cal.3d 987. (Maj. opn., ante, at pp. 1108-1109,1116-1117.) But, as Justice Baxter convincingly demonstrates in his dissent, the majority is wrong. (Dis. opn. of Baxter, J., post, at pp. 1153-1158.) This court has not previously decided this issue. In my view, the majority’s holding goes too far in imposing liability, because it fails to recognize the complexity involved in scientifically identifying a risk as meaningful and in determining whether a warning is appropriate. As this court has noted, the quality of scientific evidence “may range from extremely vague to highly certain.” (Finn v. G. D. Searle & Co. (1984) 35 Cal.3d 691, 701 [200 Cal.Rptr. 870, 677 P.2d 1147].) Scientific studies suggesting associations between products and injuries may themselves be subjected to legitimate question as to the validity of their methods and the soundness of their conclusions. (See Ramirez v. Plough, Inc. (1993) 6 Cal.4th 539, 556 [25 Cal.Rptr.2d 97, 863 P.2d 167, 27 A.L.R.5th 899] [explaining that in 1986, methodology of scientific studies showing an association between aspirin and Reye’s syndrome had been questioned, and the Food and Drug Administration had determined that further studies to confirm or disprove association were necessary]; see generally, Foster et al., Phantom Risk: Scientific Inference and the Law (1993).) The majority’s apparent standard that a prescription drug manufacturer is strictly liable for failure to warn of any “knowable” risk fails to recognize, much less deal with, the complexity of scientific evaluations. A possible result of such a standard is the destruction of the viability of any warnings. “[B]oth common sense and experience suggest that if every report of a possible risk, no matter how speculative, conjectural, or tentative, imposed an affirmative duty to give some warning, a manufacturer would be required to inundate physicians indiscriminately with notice of any and every hint of danger, thereby inevitably diluting the force of any specific warning given. [Citations.] The strength of the causal link thus is relevant both to the issue of whether a warning should be given at all, and, if one is required, what form it should take.” (Finn v. G. D. Searle & Co., supra, 35 Cal.3d at p. 701.) Too broad a standard may prove ineffective and even counterproductive. (See Ramirez v. Plough, Inc., supra, 6 Cal.4th at p. 553; Twerski et al., The Use and Abuse of Warnings in Products Liability—Design Defect Litigation Comes of Age (1976) 61 Cornell L.Rev. 495, 513-517; Prosser & Keeton on Torts, supra, § 96, p. 686 [“Too much detail can be counterproductive. A warning to be effective must be read and understood.”].) The problems of overwaming are exacerbated if warnings must be given even as to very remote risks, which drug manufacturers may find necessary under the vague standard that the majority adopts today. “Not only would such remote risk warnings crowd out potentially useful warnings but they would also focus consumer attention on the fairy tale bogeyman. One cannot cry wolf without paying the price over the long term.” (Henderson & Twerski, Doctrinal Collapse in Products Liability: The Empty Shell of Failure to Warn (1990) 65 N.Y.U. L.Rev. 265, 318.) According to the majority, its standard of liability would not result in inundating consumers with too many warnings, because the manufacturer’s duty to warn runs to the physician rather than the patient, and because there is no duty to warn of obvious dangers. (Maj. opn., ante, at p. 1116.) It is true, as the majority states, that a prescription drug manufacturer has no duty to ensure that a warning given a physician reaches the patient. (Stevens v. Parke, Davis & Co. (1973) 9 Cal.3d 51, 65 [107 Cal.Rptr. 45, 507 P.2d 653, 94 A.L.R.3d 1059].) But even physicians, the “learned intermediaries,” may be overwhelmed by excessive warnings. As this court has recognized, both common sense and experience suggest that to require a manufacturer “to inundate physicians indiscriminately with notice of any and every hint of danger” inevitably dilutes “the force of any specific warning given.” (Finn v. G. D. Searle & Co., supra, 35 Cal.3d at p. 701; contra, maj. opn., ante, at p. 1116, fn. 6.) And, contrary to the majority’s assertion, the absence of a duty to warn of known or obvious dangers has little import in the context of prescription drugs, because few of the sophisticated potential risks of prescription drugs could be considered obvious. The majority’s holding exposes prescription drug manufacturers to such broad liability that they may restrict or cease the development and distribution of life-sustaining and lifesaving drugs, thereby defeating a strong public interest. As this court has observed: “[TJhere is an important distinction between prescription drugs and other products such as construction machinery [citations], a lawnmower [citation], or perfume [citation], the producers of which were held strictly liable. In the latter cases, the product is used to make work easier or to provide pleasure, while in the former it may be necessary to alleviate pain and suffering or to sustain life. Moreover, unlike other important medical products (wheelchairs, for example), harm to some users from prescription drugs is unavoidable. Because of these distinctions, the broader public interest in the availability of drugs at an affordable price must be considered in deciding the appropriate standard of liability for injuries resulting from their use.” (Brown v. Superior Court, supra, 44 Cal.3d at p. 1063, italics added.) This distinction between prescription drugs and other products, the legal significance of which the majority denies (see maj. opn., ante, at p. 1116, fn. 5), is firmly rooted in products liability law and was the basis for this court’s unanimous decision in Brown v. Superior Court, supra, at pages 1063-1065. The concern repeatedly voiced by the courts and legal commentators that the imposition of excessive liability on prescription drug manufacturers may discourage the development and availability of life-sustaining and lifesaving drugs is well founded, as the following discussion demonstrates. In 1976, because the threat of excessive tort liability was deterring drug manufacturers from developing a vaccine for swine flu needed to protect public health, Congress enacted the Swine Flu Act, under which the federal government assumed the risk of lawsuits arising from injuries associated with the vaccine. (Pub.L. No. 94-380 (Aug. 12, 1976) §2, 90 Stat. 1113; Franklin & Mais, Tort Law and Mass Immunization Programs: Lessons from the Polio and Flu Episodes (1977) 65 Cal.L.Rev. 754, 769; see Brown v. Superior Court, supra, 44 Cal.3d at p. 1064.) In 1983, Benedictin, the only antinauseant drug available to pregnant women, was withdrawn from the market because the cost of insurance almost consumed the entire income from the sale of the drug and its price had already increased by over 300 percent. (Brown v. Superior Court, supra, 44 Cal.3d at p. 1064.) In the mid-1980’s, a producer of the diphtheria-pertussis-tetanus (DPT) vaccine withdrew its product from the market because of “extreme liability exposure, costs of litigation and the difficulty of continuing to obtain adequate insurance.” (Brown v. Superior Court, supra, 44 Cal.3d at p. 1064, quoting Hearing on Vaccine Injury Compensation Before Subcom. on Health and the Environment of House Com. on Energy and Commerce, 98th Cong., 2d Sess. (Sept. 10, 1984) p. 295.) By 1986, there were only two manufacturers of the DPT vaccine still marketing the drug and its costs had risen from 11 cents per dose in 1982 to $11.40 per dose in 1986, $8 of which was for insurance reserves. (Brown v. Superior Court, supra, 44 Cal.3d at p. 1064. ) Incidentally, that same year the unavailability of insurance prevented a manufacturer from marketing a new drug to treat vision problems. (Id. at p. 1065. ) In 1990, it was reported that the threat of products liability litigation had left the United States with just one manufacturer of the polio vaccine and one manufacturer of the combined measles, mumps and rubella vaccine. (Remarks of Sen. Heinz, 136 Cong. Rec. S16661, SI6662 (Oct. 25, 1990).) More recently, the imposition of too harsh a standard for products liability on manufacturers of prescription drugs has been mentioned as a possible impediment to this country’s ability to combat the serious public health threat posed by Acquired Immune Deficiency Syndrome (AIDS). (See generally, Arnold, Developing, Testing, and Marketing an AIDS Vaccine: Legal Concerns for Manufacturers (1991) 139 U. Pa. L.Rev. 1077.) To require prescription drug manufacturers to warn of all scientifically knowable risks, as the majority holds, exposes them to excessive liability. Such exposure creates a powerful disincentive on the part of prescription drug manufacturers to develop essential medications, especially when it is joined with the extensive liability exposure for alleged inadequacy of warnings given. (See, e.g., MacDonald v. Ortho Pharmaceutical Corp. (1985) 394 Mass. 131 [475 N.E.2d 65, 71] [adequacy of warning that use of oral contraceptive may cause abnormal blood clotting in such vital organs as the brain and that the abnormal clotting may be fatal presented question of fact because it did not use the word “stroke”]; see also Henderson & Twerski, Doctrinal Collapse in Products Liability: The Empty Shell of Failure to Warn, supra, 65 N.Y.U. L.Rev. at pp. 318-319.) In short, the broad standard of liability to which the majority subjects manufacturers of prescription drugs may cause manufacturers to issue so many warnings that the effectiveness of the most important warnings will be negated, and it jeopardizes the vital public interest in the development and availability of life- and health-sustaining drugs. Although the latter interest is advanced by the dissent’s proposed rule, the dissent’s approach places too heavy a burden on the injured consumer. III. Justice Baxter’s dissent expresses the view that a prescription drug manufacturer’s liability for failure to warn should be based solely upon negligence principles. Under that approach, a manufacturer is liable for failure to warn only if the plaintiff establishes that a reasonable manufacturer in similar circumstances would have issued warnings. (Dis. opn. of Baxter, J., post, at pp. 1147, 1162; see 6 Witkin, Summary of Cal. Law (9th ed. 1988) Torts, § 729, pp. 56-58.) The dissent agrees with the majority that the legal theories of negligent failure to warn and strict liability failure to warn are two different theories of liability: negligence looks to the reasonableness of a manufacturer’s conduct while strict liability considers it irrelevant. (Dis. opn. of Baxter, J., post, at pp. 1157-1158.) According to the dissent, the same policy considerations that led this court in Brown v. Superior Court, supra, 44 Cal.3d 1049, to adopt a negligence standard for prescript