Multiple RxNorm in C-CDA Medication

Question

Specific Question

I parsed C-CDA with BlueButton.js. Following is from the Medication JSON output. What is the RXNorm (with code system "2.16.840.1.113883.6.88") in this example? It has 577961 and 577962. Which is the correct RxNorm for the patient's medication?

"product": {
      "name": "Amphetamine aspartate 5 MG / Amphetamine Sulfate 5 MG / Dextroamphetamine saccharate 5 MG / Dextroamphetamine Sulfate 5 MG Oral Tablet",
      "text": "Adderall 20 mg tablet",
      "code": "577961",
      "code_system": "2.16.840.1.113883.6.88",
      "translation": {
        "name": "Amphetamine aspartate 5 MG / Amphetamine Sulfate 5 MG / Dextroamphetamine saccharate 5 MG / Dextroamphetamine Sulfate 5 MG Oral Tablet [Adderall]",
        "code": "577962",
        "code_system": "2.16.840.1.113883.6.88",
        "code_system_name": "RxNorm"
      }
    }

General Question

Where can I get explnanation of these C-CDA elements - that is, the difference between code element in product and translation elements?

References:

1. HL7-Referenced External Code Systems

Answer 1

So RxNorm is a terminology that used in the United States for recording and transmitting medication information. It's a complex terminology/ontology since it allows for ingredients, coordinated dose forms, brand names, generic names and a bunch more. You can browse RxNorm here online without any login:

https://mor.nlm.nih.gov/RxNav/ (they also have an API that you use, but that should get you started)

Specifically on the drugs you mentioned: 577961 is the generic format and 577962 is the brand of the same drug. According to the standard, either of those codes are technically correct since they are SCD and SBD term types respectively (Semantic Clinical/Brand Drug) I don't know if it's 100% clear whether the patient is on the brand or generic given that both codes are transmitted. There may be other information in the document regarding (such as what drug was dispensed).

In terms of learning about the standard, which is HL7 C-CDA, you could download the standard here, although this requires a free HL7 login: http://www.hl7.org/implement/standards/product_brief.cfm?product_id=492

HL7 is the standards development organization (SDO) for medical data standards. They also offer a lot of educational content on their standards. I hope this helps!