Overview. Product‑liability law allocates responsibility when a product causes injury because it is defective or lacks adequate warnings. For medical devices and prescription drugs, potential defendants range from manufacturers and designers to component suppliers and sellers; duties reach design, manufacturing, inspection, labeling, marketing, and promotion. The goal is to compensate injuries caused by unreasonably dangerous products while preserving access to beneficial therapies. (Restatement (Third) of Torts: Products Liability § 2; policy overview).
Negligence. A traditional negligence claim requires (1) duty, (2) breach, (3) proximate causation, and (4) cognizable injury. Manufacturers owe a duty of reasonable care to foreseeable users and others foreseeably affected, extending to “all aspects of the product,” including design, manufacture, inspection, labeling, marketing, and promotion. Proximate cause can turn on learned‑intermediary issues, comparative negligence, assumption of risk, and whether a feasible alternative design or different warning would have changed the outcome. See generally James T. O’Reilly & Nancy C. Cody, The Products Liability Resource Manual (ABA 1993).
Breach of warranty. Warranty claims arise under contract principles and may be express or implied. The implied warranty of merchantability asks whether the product is “fit for the ordinary purposes for which such goods are used.” U.C.C. § 2‑314. Off‑label use by physicians is not, by itself, unlawful, and FDA’s framework contemplates some off‑label physician discretion; the posture of off‑label use can complicate warranty and causation analyses. United States v. Caronia, 703 F.3d 149, 166 (2d Cir. 2012).
Fraud. Fraud‑based claims require a misrepresentation or omission of material fact, scienter, reliance, and damages. In drug and device cases, plaintiffs may allege marketing or labeling misstatements about safety or efficacy. These claims are typically harder to sustain where the record reflects regulatory compliance, independent medical judgment by prescribers, or where reliance is attenuated.
Strict liability. Strict liability does not turn on negligent conduct; the focus is whether the product was defective and unreasonably dangerous and whether that defect proximately caused injury. Modern courts commonly analyze three defect categories under Restatement (Third) § 2: manufacturing, design, and warning defects.
Manufacturing defect. A product departs from its intended design (e.g., contamination of a batch of orthopedic implants leading to infection or adverse reaction). Liability can extend upstream if the evidence ties the defect to a component or contract manufacturer. Restatement (Third) § 2(a).
Design defect. The blueprint is challenged. Jurisdictions use consumer‑expectation and/or risk‑utility tests; many require proof of a feasible alternative design that would have reduced foreseeable risks without unduly impairing utility. Restatement (Third) § 2(b). Courts treat “unavoidably unsafe” therapeutic products with care—often invoking comment k to Restatement (Second) § 402A to limit strict‑liability design claims where properly prepared products carry adequate warnings and therapeutic benefits outweigh residual risks. See, e.g., § 402A cmt. k; jurisdictional approaches vary between categorical and case‑by‑case applications.
Warning defect (failure to warn). A warning defect exists where the manufacturer fails to provide adequate instructions or risk information. In prescription contexts, the learned‑intermediary doctrine generally directs the duty to warn to the prescribing healthcare professional, who then advises the patient. Restatement (Third) § 2(c).
