How to cite a drug name in AMA Style journal article? In my paper, I have used a drug name called Metformin. But I received a comment from Editor to cite the drug name.
May I know how can I cite the drug name in AMA style?
There could be multiple suppliers/companies that produce/manufactures this drug from a different location
Can help me with this?
Usually you cite drug package inserts.
See Chapter 3.13.6 of the AMA Manual of Style (11th ed.):

Package inserts, patient information, and prescribing information (the material about the use and effects of the product) may be cited as follows:

Zithromax. Prescribing information. Pfizer; 2017. Accessed June 23, 2019. https://www.pfizermedicalinformation.com/en-us/zithromax
Azilect. Package insert. Teva Pharmaceuticals Inc; 2014.


The general pattern, as I see it, would be: Drug. Type-of-document. Manufacturer. Date. Optional-internet-access-date. Optional-internet-source..
If there are multiple manufacturers for one drug, you could cite all of them (as long as that seems appropriate for the specific context within your publication).