This was implemented in PubMed in mid August. Search for a drug that is included on a list of 200 or so, and on the Summary Results screen (the list of references), you will see links to other resources about the drug. Currently the link is to PubMed Clinical Q and A, which is one of the items on the NCBI Bookshelf.
This is a separate thing from what you see when looking at an individual item from a list of results, when there may be a link to more information about the drug in MedlinePlus, which will appear under a heading "Patient Drug Information".
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