Directions for use

Adequate directions for use are a core US labeling requirement in 21 CFR 801, with IVD-specific rules in 809.10. When directions change, the manufacturer assesses whether the change affects the indications for use or could significantly affect safety or effectiveness.

The directions or instructions under which the user can use the device safely and for the purposes for which it is intended. Directions for use requirements applicable to prescription and over-the-counter devices appear throughout 21 CFR Part 801, and 21 CFR 809.10 for IVD devices.

FDA guidance: Deciding When to Submit a 510(k) for a Change to an Existing Device (October 2017), Appendix C, Significant Terminology