Please note that there are no "updates" to drug labels in the traditional sense -- any change in labeling information requires issuance of a new version of the SPL document. effective_time
serves as a "creation date" for that particular version.
I think you can still rely on the effective_time
field in your searches but also look at the value of the version
field. Value of 1
would indicate "creation" in the traditional sense (initial issuance of the drug label), while values higher than 1
would indicate "updates". For example, here is a query for drug labels created since the beginning of the year:
https://api.fda.gov/drug/label.json?search=effective_time:[20210101+TO+20211231]+AND+version:%221%22
Hope this helps.