To the Editor.—Will you kindly give me the correct use of the word “ad” in prescription writing? If, after indicating the amount of basis, adjuvant, etc., the name of the vehicle is followed by “ad” with the number of ounces indicated, shall the whole amount of prescription be brought to this amount or shall the amount of the vehicle be added? Does the use of q. s. preceding or following the word “ad” change its significance? There seems to be some confusion in regard to the matter; some claiming that “ad” is synonymous with add.
Queries and Minor Notes. JAMA. 2008;300(12):1471. doi:10.1001/jama.300.12.1471-b