What about MeSH?
The MeSH Browser is an online vocabulary look-up aid available for use
with MeSH® (Medical Subject Headings). It is designed to help quickly
locate descriptors of possible interest and to show the hierarchy in
which descriptors of interest appear. Virtually complete MeSH records
are available, including the scope notes, annotations, entry
vocabulary, history notes, allowable qualifiers, etc. The browser does
not link directly to any MEDLINE or other database retrieval system
and thus is not a substitute for the PUBMED system.
If you query for Carbidopa
at http://www.nlm.nih.gov/mesh/MBrowser.html you will get an html table with a row like
Scope Note
An inhibitor of DOPA DECARBOXYLASE, preventing conversion of LEVODOPA to dopamine. It is used in PARKINSON DISEASE to reduce peripheral adverse effects of LEVODOPA. It has no antiparkinson actions by itself.
If you query for alendronate
you'll get
Scope Note
A nonhormonal medication for the treatment of postmenopausal osteoporosis in women. This drug builds healthy bone, restoring some of the bone loss as a result of osteoporosis.