This page is part of the MII Implementation Guide MII IG Medikation (v2027.0.0-ballot: 2027 Ballot 2) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

Code Systems

Terminologies

Wherever possible, terminologies and unique codes conforming to international standards are to be used. For medicinal product and dosage information these are the ISO standards for the Identification of Medicinal Products (IDMP), which are implemented above all in the regulatory context.

Active ingredients

The following are proposed as unique identifiers (codes) for active ingredients:

• Substance codes of the German medicinal substance catalogue of the BfArM (ASK). How this ASK number is made publicly available via URI/URL through the BfArM or ABDATA (§ 31b SGB V) still needs to be clarified.
• The Unique Ingredient Identifier (UNII) of the US Substance Registration System. It is not available in Germany.
• The CAS Registry Number from the Chemical Abstracts Service database.
• SNOMED CT codes from the substance hierarchy. These codes are not contained in the German databases (PharmNet/AMIS and ABDATA).

For naming substances, the registered substance names can be used; these are usually — but not always — the WHO INNs (International Non-proprietary Names). Within the MII the German spelling should be used, which in some cases differs slightly from the English version.

It is recommended to use ATC codes (Anatomical Therapeutic Chemical classification) for coding active ingredients only with reservations, since an ATC code cannot be assigned unambiguously to a substance.

Ingredient type

For active ingredients it should be possible, when calculating dose information, to distinguish between the precise ingredient (which may be a salt, ester and so on) and the pure ingredient, and to state whether the calculation is based on the derivative (less common) or on the pure, general, normalised substance (usually). An extension was therefore defined that can be attached to the ingredient coding. It references a value set with the codes:

• IN — ingredient, general active ingredient
• PIN — precise ingredient
• MIN — multiple ingredients, combination code for several active ingredients

See the extensions Wirkstofftyp and Wirkstoffrelation.

Sales status of a PZN

Pharmazentralnummern are volatile: an article that is no longer in today's catalogue may well have been regularly on the market at the time of treatment. So that this can be documented, the module carries the sales status codes of the MMI Pharmindex (catalogue #116) as a code system of its own: MII CS Medikation PZN Sales Status Codes.

Code	Meaning	Description
N	On the market	The article is available on the market and distributed by the supplier
F	Withdrawn from distribution	Stock may be sold off, provided the marketability status allows it
D	Lapsed	Marketability has expired
R	Recalled	The article has been recalled and must no longer be dispensed
Z	Withdrawn	The article has been withdrawn and must no longer be dispensed

The value is intended to be carried as a property on a PZN coding — it describes the article, not the prescription.

Medicinal products

The following are proposed for identifying medicinal products:

• the Pharmazentralnummer (PZN). These numbers must be made queryable via a publicly available URL/URI (§ 31b SGB V).
• the Pharmaceutical Product Identifier (PHPID), which is part of the ISO IDMP standards but is currently not available.

Combination packages

For combination packages — where the medicinal product consists of several components with different active ingredients, dose forms, doses or dose units — two representations are currently permitted on the medication plan and in the carrier:

Variant 1: one shared PZN. The combined finished medicinal product is coded with a single PZN, so that it appears as one medication entry. The dosage should then be entered as free text by the user to account for both components. An additional bound line can provide room for further explanation.

Variant 2: two or more PZNs. The individual components are coded with two or more PZNs. In that case the combined product is represented by splitting it across corresponding, consecutive medication entries. There is currently no structural way to express that such entries belong together as one combined product; the user can establish that relation with suitable text, if necessary under a separate subheading.

Route of administration and dose form

For the route of administration and the dose form the following are to be used:

• the standard terminologies of the EDQM (European Directorate for the Quality of Medicines and Health Care), "Routes and Methods of Administration" and "Pharmaceutical Dose Forms".
• alternatively the dose form may be given as an IFA code, per the KBV medication plan specification. Key table: https://applications.kbv.de/S_BMP_DARREICHUNGSFORM_V1.02.xhtml

The EDQM standard terminologies should be preferred, since they conform to the ISO standards for the Identification of Medicinal Products.

Context in which medication is used

Codes distinguishing the context in which a medication list (List) is maintained, or categorising a medication statement (MedicationStatement), are given in the value set MII VS Medikation Fallkontext.

Canonical: https://www.medizininformatik-initiative.de/fhir/core/modul-medikation/ValueSet/fallkontext

List of external code systems

URI	Source	Comment	OID (for non-FHIR systems)
http://fhir.de/CodeSystem/ifa/pzn	PZN Pharmazentralnummer		1.2.276.0.76.4.6
http://fhir.de/CodeSystem/bfarm/atc	ATC Anatomical Therapeutic Chemical classification	German edition
http://fhir.de/CodeSystem/ask	Arzneistoffkatalog number		1.2.276.0.76.5.308
http://fdasis.nlm.nih.gov	UNII Unique Ingredient Identifier	Using UNII with FHIR	2.16.840.1.113883.4.9
http://terminology.hl7.org/CodeSystem/CAS	CAS registry system	unique numerical identifier of a substance in the CAS Registry system	2.16.840.1.113883.6.61
http://standardterms.edqm.eu	EDQM Standard Terms		0.4.0.127.0.16.1.1.2.1
http://snomed.info/sct	SNOMED CT snomed.org	Using SNOMED CT with FHIR	2.16.840.1.113883.6.96
http://unitsofmeasure.org	UCUM unitsofmeasure.org	Using UCUM with FHIR	2.16.840.1.113883.6.8
http://ihe-d.de/CodeSystems/FallkontextBeiDokumentenerstellung	IHE XDS Fallkontext bei Dokumentenerstellung		1.3.6.1.4.1.19376.3.276.1.5.16