處方藥標示外使用為通常且重要之醫療實務，而若醫師善盡其醫療之注意義務，以開立標示外使用之處方，則病患可獲得治療利益，但關於「處方藥標示外使用」之安全性，提供處方藥流通於市面之藥品製造商及開立標示外使用處方之醫師，均有其應盡之義務及責任。因此，本文從民事侵權責任之觀點，探討處方藥標示外使用之消保法商品製造人責任，即醫師之處方藥標示外使用行為，對藥品製造商瑕疵責任之認定有無影響。另進一步探討處方藥之標示外使用是否即為醫師注意義務之違反，而應對病患負擔過失侵權之損害賠償責任。最後，探究醫師之告知同意範圍是否涵蓋其特定用藥之性質上屬標示外使用行為，且醫師之告知同意內容是否因標示外使用行為，而應有所改變。

Off-label prescription of drugs occurs when a doctor prescribes a drug in any manner that varies from labeling specifications, which are limited to FDA-approved uses. Off-label prescribing of drugs is a common and significant part of current medical practice. In addition to being accepted medical practice, off-label prescribing of drugs often can help patients with optimal care as long as doctors prescribe them with due care. Under the right circumstances,off-label prescribing is often appropriate, but it also creates special risks that are not present
when the prescribing is on-label uses. Therefore, drug manufacturers and prescribing doctors should take on the civil liabilities in tort for injuries caused by off-label drug uses in order to achieve the safety and efficacy of off-label uses of prescription drugs.First, this Article analyzes the manufacturers’ product liability of drug manufacturers
under Taiwan Consumer Act for injuries stemming from off-label uses of prescription drugs.It examines the issues on whether off-label prescribing of drugs affects the determination of manufacturing, design, and warning defects. Further, this Article examines whether off-label
prescribing of drugs is negligence per se and thus prescribing doctors are liable for medical malpractice. Finally, this Article examines whether the tort doctrine of informed consent should be expanded to require doctors to disclose off-label prescriptions, and whether the
contents of it should be extended with regard to the act of off-label prescribing of drugs.