2.2 Medicinal Product Precisely (MP precisely)

Definition

An abstract representation of a medicinal product based on description of only and exclusively the precise active ingredients it contains.

For example, "Product containing amoxicillin sodium precisely" represents products that must contain precisely amoxicillin sodium not amoxicillin trihydrate nor a substance that is any further modification of amoxicillin sodium, should one exist; and they must not contain any other active ingredients, such as clavulanic acid. 

Use cases

The use case for the MP (precisely) concept is primarily to provide a more exact and explicit medicinal product concept for use in those scenarios where different modifications of the base active ingredient have clinical significance - usually because of different potency and different dosing schedules. There are several groups of products where this is the case, for example the corticosteroids, various of the anti-epileptic medications (e.g. phenytoin and valproic acid), and insulins.  The the MP (precisely) class can be deployed in national extensions for those use cases that need it, such as prescribing scenarios (so called "abstract" or "non-product-based" prescribing where no product and no dose form are specified by the prescriber) and in medication history and in medication profiles, and in decision support, in protocols and treatment guidelines.  However, all the use cases described for MP (only) could use MP (precisely) as necessary when more exact and explicit representation is required.

Discussion

A Medicinal Product (MP precisely) concept may be created in national extensions when use case(s) require this and for those national extensions where products exist such that the active ingredient count attribute for the MP precisely has a different value from the active ingredient count of the parent Medicinal Product (MP only) concept.  

Attributes

The Medicinal Product precisely (MP precisely) concept is defined by two groups of attributes; to describe the precise active ingredient(s) and the ingredient count(s).  The ingredient count attributes are applied incrementally, as the requirement arises for MP precisely concepts; this is a pragmatic and incremental approach to maintenance of the hierarchy.  Although it is desirable for attributes to be applied globally, this would introduce a significant maintenance burden for what is required in only a minority, although a significant minority, of cases.  They are applied when the requirement to describe products that contain two or more active ingredients that are modifications of the same base and are applied from the top down (i.e. from the MP precisely class, down to the clinical drug class, including the MPF precisely if required) within the particular sub-hierarchy base ingredient concept.

In national extensions using the MP precisely concept related to CD concepts in the international edition which do not have multiple ingredient counts may give classification results are not as initially expected; in this case it may be necessary to override the international definition of some concepts in the sub-hierarchy in the national extension (e.g. if a CD containing one of the precise ingredient substances has only one count attribute in the international, but requires two or three count attributes in the national in order to get correct classification into an MP precisely concept).

Example diagrams

Example: product with a "multiple modified" active ingredient substance (dexamethasone phosphate is the modified concept that has a further modification to give dexamethasone sodium phosphate): stated view,  showing both the count of the base active ingredient and the count of base and modification pair are present, as the substance has a multiple modification (dexamethasone phosphate is the modified concept that has a further modification to give dexamethasone sodium phosphate) and there are multi-ingredient concepts that contain this multiple modified substance and at least one other modified ingredient substance that shares the same base substance (dexamethasone) (see next examples). The multi-ingredient concept is "dexamethasone sodium phosphate and dexamethasone acetate".  As described in the MRCM rules, the additional ingredient count attributes have to be applied iteratively.  The following inferred view shows the correct dexamethasone moiety MP (only) parent concept.

Figure 13:  Single Ingredient Medicinal Product (precisely) example stated view 

Figure 14: Single Ingredient Medicinal Product (precisely) example inferred view 

Example: multi-ingredient concept, where both precise active ingredient substances share the same base moiety substance, showing requirement for two ingredient count attributes; note that because these attributes must be applied iteratively, the MP precisely concepts exist for each single ingredient product

Figure 15: Medicinal Product (precisely) example stated view - multi-ingredient concept 

Figure 16: Medicinal Product (precisely) example inferred view - multi-ingredient concept 

The count of base and modification pair ensures that this multi-ingredient product does not incorrectly subsume under either of the single ingredient products, since they have a base and modification pair count of one and this has a base and modification pair count of two. It can subsume under the parent "Product containing only dexamethasone" as shown in the diagram above, as "Product containing only dexamethasone" has a count of base of active ingredient of 1, and that one is dexamethasone (substance), which is the same as for the "Product containing only dexamethasone acetate and dexamethasone sodium phosphate".

The requirement for all the three ingredient count attributes depends significantly on how the substance hierarchy is modelled.  For example, with calcium products (calcium lactate and calcium lactate gluconate) if both are considered modifications of "calcium (substance)" then for multi-ingredient products containing both, the three ingredient counts would be required to obtain correct classification for MP only and MP precisely concepts. 

For further details, see the Ingredient Count attributes in the International Model specification.