Drug injury cases fall under the umbrella of product liability cases, meaning that the product itself—not the humans using or prescribing it—are the subject of the lawsuit. Any product that is made and sold to consumers has guidelines it must follow in order to be considered safe. If these guidelines are not met and someone gets hurt or killed, it can lead to a product liability case.
On the other hand, a medical malpractice or medical negligence case has an element of human error. If a healthcare professional at any level fails to follow standard protocol or makes a serious mistake, they can be held responsible for whatever injuries happen to a patient. If, for instance, your doctor prescribed a drug without warning you about its known risks or side effects, you might have a medical malpractice case as opposed to a drug injury case.