RxNORM defines drugs. It declares that Warfarin Oral Tablet is the ingredient Warfarin combined with the dose form Oral Tablet. It tells us that this compound is sold under four catchy names, Coumadin, Jantoven, Marfarin and Narfarin.

But there’s more inside RxNORM’s awful release format, a hefty gem from the VA called National Drug File, Reference Terminology (NDFRT). With NDFRT, drugs like Warfarin are matched to disorders …

     :N0000148057 :contraindicated-for :N0000000988  # Warfarin is contraindicated for Diverticulitis 
...
     :N0000148057 :may-prevent :N0000004160  # Warfarin may prevent Stroke 
...
     :N0000148057 :may-treat :N0000000507  # Warfarin may treat Atrial Fibrillation

and it tells you what drug combinations to watch out for …

     [] :participant :N0000148057 # Warfarin
        :participant :N0000146291 # Hydrocortisone
        :severity "SIGNIFICANT"

or watch out! The interaction between Warfarin and Hydrocortisone may be significant.

NDFRT gets us beyond drug x has ingredient y. We’re told what a drug is for and what to watch out for.

Is it perfect? No. One biggie – it uses MeSH for disorders and while there are maps to SNOMED, some of these are questionable and others are to obsolete concepts (162 of 1099 mapped).

It can also surprise. Did you know the VA can make you live forever? NDFRT declares …

    :N0000146382 may_prevent :N0000000903 # Antiven may prevent Death

Antiven,Micrurus Fulvius, the immortality pill.

But putting quirks aside, it shows once again that VistA and the VA terminologies are a treasure-throve for next-generation EHRs. Decision-support everybody?