Table 1.

Comparing US FDA authorization of drugs and devices

	Drugs	High-risk devices	Medium-risk devices
Year FDA began mandating proof of safety and efficacy	1962	1976	N/A
Authorization process	New drug application (NDA)	Premarket approval (PMA)	510(k) clearance
Standard of evidence	Substantial evidence that the drug will have the effect it purports or is represented to havea	Reasonable assurance of safety and effectiveness	Substantial equivalence to a predicate device
Supporting data	Clinical trials and pre-clinical studies	Clinical trials and pre-clinical studies	Pre-clinical studiesb
Process for introducing post-authorization changes	Nonec	PMA supplement pathways	New 510(k) clearance
Tort liability claims against manufacturer mostly preempted?	No	Yes	No

^aSubstantial evidence is defined as “adequate and well-controlled investigations, including clinical investigations”

^bClinical trials are rarely required as part of the 510(k) process

^cChanges to the molecular structure of an active ingredient require their own New Drug Application. In some instances, the FDA may approve new formulations of an approved drug based on bioequivalence studies