As published by the Office of the National Coordinator for Health Information Technology (ONC) the applicable vocabulary standard for drugs is RxNorm and for substance drug classes, meaning the Pharmacologic category for an agent believed to cause a harmful or undesired physiologic response following exposure, the  Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT®) U.S. Edition, March 2023 Release.
 Rererence: https://www.healthit.gov/isa/uscdi-data-class/allergies-and-intolerances#uscdi-v4 .

Since the beginning of providing drug risk checking software SCHOLZ Databank (SDB) supported  the major topics of concern which are drug drug interactions, adverse drug effects, contraindications, precautions, and drug allergies. Meaningful Use Stage 1 required already drug interaction and drug allergy checking as obligatory in the doctor's daily business. 

For that purpose and to support the targets of interoperability between diverse healthcare IT systems according to Meaningful Use Stages 2 and higher the proprietary terminology and coding system of SDB contains for more than ten years the interface to the RxNorm vocabulary and as required for classifying ingredient related allergies the FDA UNIICodes, too. Thereby any practice or hospital using SDB should be able to process and submit drug allergy relevant information in medication analysis and communicating patient drug allergy history. 

To fulfill most recent ONC requirements this complex system of terminology and codes is now supplemented by interfacing to the SNOMED allergy substance drug classes. Thereby allergy group codes provided by SNOMED are integral part of all webservice functions of SDB related to allergy checking and intersectoral patient drug allergy communication. Another step to improve safer prescription of drugs to patients and prevent avoidable medication errors.