Atrovent UDVs,

http://www.hmdb.ca/metabolites/HMDB0014476
http://www.genome.jp/dbget-bin/www_bget?cpd:C07052
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=657308
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46506138
https://www.chemspider.com/Chemical-Structure.19962157.html
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=7213
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=46659
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL1621597
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DNC000806
http://www.pharmgkb.org/drug/PA450082
http://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=325
http://www.rxlist.com/cgi/generic/ipratrop.htm
https://www.drugs.com/mtm/ipratropium-nasal.html
https://en.wikipedia.org/wiki/Ipratropium_bromide