Also known as: inadequate warning · inadequate warnings doctrine · failure to warn · warning defect
Written by attorneys · grounded in primary & secondary sources — see below
A basis for holding a product defective in strict products liability when the manufacturer fails to provide users with sufficient information regarding known or foreseeable dangers.
Isabelle Inman received a prescription for a new medication from her doctor. The manufacturer had sent the physician a detailed letter describing the precise risk of organ damage that later materialized. When Isabelle sued the manufacturer claiming inadequate warnings, the court held the manufacturer not liable because the warning to the learned intermediary was complete.
Iris Irons suffered a severe reaction after using a prescription device. The manufacturer had distributed updated risk information to physicians and hospitals across the state. Iris's direct failure-to-warn claim against the manufacturer failed because the duty ran only to the prescribing physician under the learned intermediary rule.
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Isabella Ingram sued a device maker after experiencing complications. The manufacturer had provided the surgeon with current risk data, yet Isabella offered only general evidence that surgeons knew of the hazard. The court granted summary judgment because she could not show that a different warning would have altered the physician's choice.
Imran Iyer developed gangrene after an injection. The drug complied with FDA labeling rules, but the jury found the warnings still inadequate under state tort law. The manufacturer remained liable because federal compliance did not preempt the state inadequate-warnings claim.
Israel Irving took a generic drug and suffered a serious side effect. The manufacturer could not unilaterally change the label to add stronger warnings. The court dismissed the inadequate-warnings claim because federal law made it impossible for the generic maker to comply with any state duty to warn.
Ibrahim Iqbal told his therapist of a specific plan to harm a named individual. The therapist took no steps to warn the potential victim. The court held the therapist could be liable for the resulting injury because the failure to warn breached the duty to protect foreseeable third parties.
The doctrine applies when the manufacturer provides adequate risk information to the prescribing physician. The physician's independent judgment then breaks the chain of causation to the patient unless the warning to the doctor was itself inadequate or misleading.
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The plaintiff must show that an inadequate warning to the physician would have changed the prescribing decision. Generalized evidence that physicians were already aware of the risk is insufficient.
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No. A manufacturer may still face liability under state tort law even when its label complies with FDA requirements, because federal law does not preempt failure-to-warn claims against brand-name drug makers.
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…and what warnings must be given.[^maj-2] Moreover, legislation could provide consequences for the misadvice, nonadvice, or failure to warn, other than nullification of a criminal conviction after the witnesses and evidence needed for retrial have disappeared. Federal immigration law might provide, for example, that the…