PROPERTIES AND UNITS IN THE CLINICAL LABORATORY SCIENCES

XII. PROPERTIES AND UNITS IN CLINICAL PHARMACOLOGY AND TOXICOLOGY

Technical report IFCC-IUPAC 1999)

 Prepared for publication by

 Henrik  Olesen1, David Cowan2, Rafael de la Torre3 , Ivan Bruunshuus1,  Morten Rohde1, Desmond Kenny4  

 1Office of Laboratory Informatics, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
2Drug Control Centre, London University, King’s College, London, United Kingdom
3IMIM, Dr. Aiguader 80, Barcelona, Spain
4Dept. of Clinical Biochemistry, Our Lady’s Hospital for Sick Children, Crumlin, Dublin 12, Ireland

 The combined Memberships of the Committee and the Commission (C-NPU) during the preparation of this report (1994 to 1996) were as follows:

Chairman: 1989-1995 H. Olesen (Denmark); 1996 - D Kenny (Ireland). Members:  X. Fuentes-Arderiu (Spain; 1991-1997); J.G. Hill (Canada; 1987-1997); D. Kenny (Ireland; 1994-1997); H. Olesen (Denmark; 1985-1995);  P.L. Storring (United Kingdom; 1989-1995);  P. Soares de Araujo (Brazil; 1994-1997); R. Dybkęr (Denmark; 1996-1997); C. McDonald (USA; 1996-1997).

 Please forward comments to:
H. Olesen, Office of Laboratory Informatics 76-6-1, Copenhagen University Hospital (Rigshospitalet), 9 Blegdamsvej, DK-2100 Copenhagen, Denmark. E-mail: holesen
@rh.dk

Synopsis

The term designating a substance being an active ingredient of a drug may be a generic name, a nonproprietary name, a registered trade name, a fantasy name or other. This causes difficulties in the transmission of requests and reports on properties for such substances in biological fluids to and from the clinical laboratories, and in the collating of this information from different sources.
     The document comprises a list of properties of drugs in biological fluids for use in electronic transmission systems. Systematic names are presented together with a code value for each.

Preface

The present document is part twelve (XII) of a series on properties and units in the clinical laboratory sciences initiated in 1987.

      The series will comprise:

I           Syntax and semantic rules [1]
II          Kinds-of-property [2]
III         Elements (of properties) and their code values
IV         Properties and their code values
V          Properties and units in Thrombosis and Haemostasis
VI         Properties and units in IOC prohibited Drugs
VII        Properties and units in Inborn Errors of Metabolism
VIII       Properties and units in Clinical Bacteriology
IX         Properties and units in Trace Elements
X          Properties and units in General Clinical Chemistry
XI         Coding systems - structure and guidelines [3]
XII        Properties and units in Clinical Pharmacology and Toxicology
            (this report)
XIII      Properties and units in Reproduction and Fertility
XVI      Properties and units in Clinical Allergology

The size and complexity of parts III and IV are such that their lists will be presented in electronic format. This is for ease of handling and to facilitate expression of concepts in different languages.
      At the end, systematic names, elaborated according to international standards and recommendations should be available in the different domains of clinical laboratory sciences. The core of the series is code value strings representing concepts, that in combination delineate and define each property regardless of linguistic expression, thus avoiding errors during translation between languages.

Foreword and Scope

Clinical Laboratory Sciences are characterised by the exacting nature of the work performed and the demand for an accurate presentation of the outcome.
Further the domain is transnational, international or "global".
      The adherent informatics system therefore needs to identify the findings accurately and to present them with the degree of detail required. At the same time it has to facilitate the transfer over linguistic and cultural barriers without distortion or loss of clarity, in order to promote clear, unambiguous, meaningful and fully informative communication in different terminologies.
      The degree to which a message (such as a laboratory report) needs to be expressed in a formal, systematic language depends on the geographical, linguistic, social or professional distance between the communicating parties. The greater the distance, the greater the risk of misunderstanding.
      Within one laboratory, local jargon terms may be used which are usually well understood between colleagues, but which would not be sufficiently widely known for communication with the outside world. Likewise, a laboratory and its local community of users, such as hospital or community physicians, may use a "local dialect" of the language of clinical laboratory sciences which is well understood by all concerned; but when the communication possibilities are wider, even transnational, risks of serious misunderstanding arise.
      The purpose of this document is to apply the IFCC–IUPAC recommended syntax structures for request and report and to create a systematic terminology which can be used as the basis for encoding laboratory messages in the domain of drugs. The systamatic names recommended here are primarily for the purpose of unambiguous data exchange. Their use in routine language by clinician or laboratory practitioners is optional but encouraged.

Definitions

component: definable part of a system [ENV 1614; 4]
EXAMPLE: Dextropropoxyphene as part of a plasma sample
discrimination value: value of a quantity established from purpose related considerations
NOTE 1 - The term cut-off value is used as a synonym.
detection limit: result of a measurement by a given measurement procedure for which the probability of an analytically false negative result is b, given the probability a of an analytically false positive result [5]
drug: substance which when absorbed into a living organism may modify one or more of its functions [6]
NOTE -  The term is generally accepted for a substance taken for a therapeutic purpose, but is also commonly used for abused substances
kind-of-property: attribute of phenomena, bodies or substances that may distinguished qualitatively [after ENV 1614; 4]
NOTE 1 - In ENV 1614 the term property (in a general sense) is used as synonym for kind-of-property.
NOTE 2 - A kind-of-property may be related to nominal scale (ex. green; blue), ordinal scale (ex. small; large), difference scale (ex. 10 °C (i.e. 10 °C more than an arbitrary zero)) or ratio scale (length 2 m or 5 m); the last two types of kind-of-property are also called kind-of-quantity.
nominal scale: scale with a set of possible values for a given kind-of-property that are each a word or symbol without any relation to magnitude [5]
EXAMPLE: Names of  analgesic drugs.
NOTE - The values may be listed in any arbitrary order according to practical considerations and convention.
ordinal scale: scale with an ordered set of possible values for a given kind-of-property that are each a word or symbol used for ranking according to magnitude, but where differences or ratios between values have no arithmetic meaning [5]
EXAMPLE: arbitrary concentration of cannabinoid in urine (“not detected”; “detected” or 0 1).
difference scale: scale with an ordered set of possible values of a given kind of measurable quantity that are each a product of numerical value and unit of measurement such that a given difference between values corresponds to the same difference between magnitudes of the measurable quantities along the scale [5]
EXAMPLE: (substance concentration increment)  -32 µmol/l
property: set of data elements comprising information on system, component and kind-of-property and their adherent specifications.
NOTE 1 - There is presently no officially approved definition of this concept. The present definition is for use in this document only.
NOTE 2 - Information about identification of system, time and result is not considered.
EXAMPLE: substance concentration of fentanyl in blood plasma.
ratio scale: scale of measurement with an ordered set of values for a given kind of measurable quantity that are each a product of numerical value and unit of measurement such that a given ratio between values corresponds to the same ratio between magnitudes of the measurable quantities along the scale [5]
EXAMPLE: 0   0,1   0,2   -   -   -   31   32  µmol/l.
system: demarcated arrangement of a set of elements and a set of relationships between these elements [ENV 1614; 4].
EXAMPLE: a portion of urine, a portion of blood.

Systematic Request and Report of Clinical Laboratory Results

By convention, properties and results of examinations are represented by the equation:

Equation 1

Property =  Result

The parts comprised in the concept of ‘property’ and in the concept of ‘result’ are presented in table 1.

Tab. 1. Systematic request and report

1

Identification and time

1.1

object or patient identification

1.2

date and time(s) of sampling

 

 

2

Property

2.1

System

2.2

Component

2.3

kind-of-property

 

 

3

Result

3.1

Equality, inequality or other operator

3.2

value (for quantities on a difference or ratio scale, a numerical value multiplied by a unit)

 

 

4

Notes

·       Essential for a request  is parts 1 and 2, that is information on patient identification, time or time interval for sampling, and information on the property requested.

·       The laboratory report on a particular property comprises the three parts 1, 2 and 3.

·       To each element in part 2 may be added a specification as a parenthetic suffix for clarification, identification and to avoid ambiguity.

·       Note(s) (part 4) relating to, for example, diagnosis, medication, haemolysis or hardware breakdown are not included, except when needed for the interpretation of results such as pretreatment of patient or subject.

·       Thus the elements of a term for a type of property comprise: System(specification)—Component(specification); kind-of-property(specification)

·       This is as recommended by IFCC and IUPAC (3) and by the European standard ENV 1614:1995 [4]

·       EXAMPLE [NPU02164]

      Plasma—Gentamicin; substance concentration

·       The elements of a result comprise: an operator (= < £ > ³ etc.), a numerical value and a unit, usually in symbolic form. This is as recommended by the European standard ENV 12435:1996 [7]

·       EXAMPLE [NPU02164]

      = 6 µmol/l (prefix µ: micro = 10-6)

·       Nominal and ordinal scale values carry no unit. In difference and ratio scales the unit must never be omitted in reporting results, except for the unit 1.

·       It is further recommended that the result includes or refers to a value for a measure of uncertainty [7].

·       The names of components are from the International Nonproprietary Names (INN) of WHO [8] for pharmaceutical substances (English, French, Russian and Spanish). If not recorded in INN, preference is for CAS trivial names [9], USAN [10], BAN [11], Martindale [12], in that sequence.

·       In addition to the systematic name of the property, an example and other useful information are given.

For details, see IUPACIFCC (Recommendations 1995). Syntax and semantic rules [1].

Most drugs are metabolised by the organism. Therefore the analytical findings pertain to the drug administered and to its metabolites. Often the non-modified drug is hardly detectable. If so, the result given to the requester is on the parent compound in the form of a result deduced from the presence of specific metabolites. Information on metabolites found is part of the report and is given after a “deduced from”.

Elements of an Entry

The terms recommended are given in bold, that is: the systematic term for the type of property, the unit and the code value.

  1. Name of system and parenthetic specification spelled out in full, and followed by a long dash (em dash).

  2. Alphanumeric chemical prefixes to component name.

  3. Recommended name of component and parenthetic specification. Shifted to the left for alphabetical sorting and searching, and followed by a semicolon.

  4. Kind-of-property and parenthetic specification.

  5. Unit.

  6. Other term(s)

  7. Authority: Code value for the international organization recommending the name of the component or the combined elements of an entry

  8. Note(s) with any further information

  9. [NPUXXXXX] Coding scheme identifier and code value, intended for interlaboratory transmission between databases

  10. Example in abbreviated form.

 The term “arbitrary” in princible cannot be related to a volume. In clinical chemistry however a less well defined “inhouse” or a regional calibrator is often referred to and is expressed in “arbitrary unit per litre” in order to enable comparison of patient data over time and regionally. In each of these instances further information should be given in the parenthesis “procedure”. This could be information on the calibrator used, f.ex. “BCR/CRM148/149R  or it could refer to the inlaboratory document “procedure xx”. which is available on request.

In the examples given, a question mark, “?”, has been used to represent the value of a result for properties including quantities.

EXAMPLES          

a.                Nominal scale

1.           Urine—
3.       Analgesic drug;  
4.           taxon(procedure)
9.           [NPU04479]
10.          UAnalgesic drug; taxon(Firm xxx) = Buprenorphine; Dextropropoxyphene

1.           Urine—
3.    Narcotic drug;
4.           taxon(procedure)            
9.           [NPU08930]
10.          U—Narcotic drug; taxon(Firm xxx) = Cocaine
              deduced from
              Benzoylecgonine (CAS519-09-5)
              Ecgonine (CAS481-37-8)


b.           Ordinal scale

    In the actual reporting the possible scale values should be listed in the parenthesis after the kind-of-property.

1.           Urine—
3.       Analgesic drug;
4.           arbitrary concentration(list; procedure)
9.           [NPU04845]
10.          U—Analgesic drug; arb.c.(list; 0 1)
              [NPU04934] U—Alphaprodine; arb.c.(0 1) = 0 
              [NPU04401] U—Anileridine; arb.c.(0 1) = 0 
              [NPU04584] U—Buprenorphine; arb.c.(0 1) = 1
              [NPU01710] U—Codeine; arb.c.(0 1) = 0 
              [NPU04916] U—Dextromoramide; arb.c.(0 1) = 0
              [NPU01866] U—Dextropropoxyphene; arb.c.(0 1) = 1
              [NPU04450] U—Diamorphine; arb.c.(0 1) = 0 
              [NPU04454] U—Dipipanone; arb.c.(0 1) = 0 
              [NPU04463] U—Ethoheptazine; arb.c.(0 1) = 0
              [NPU04464] U—Ethylmorphine; arb.c.(0 1) = 0 
              [NPU02032] U—Fentanyl; arb.c.(0 1) = 0
              [NPU02408] U—Hydrocodone; arb.c.(0 1) = 0
              [NPU02523] U—Ketobemidone; arb.c.(0 1) = 0
              [NPU04497] U—Levorphanol; arb.c.(0 1) = 0
              [NPU02722] U—Methadone; arb.c.(0 1) = 0
              [NPU02846] U—Morphine(non-complexed); arb.c.(0 1) = 0
              [NPU04536] U—Nalbuphine; arb.c.(0 1) = 0
              [NPU04591] U—Oxycodone; arb.c.(0 1) = 0 
              [NPU04596] U—Paracetamol; arb.c.(0 1) = 0 
              [NPU03035] U—Pentazocine; arb.c.(0 1) = 0
              [NPU03049] U—Pethidine; arb.c.(0 1) = 0
              [NPU04599] U—Phenazocine; arb.c.(0 1) = 0
              [NPU03384] U—Salicylate; arb.c.(0 1) = 0
              [NPU04549] U—Tramadol; arb.c.(0 1) = 0 
              [NPU04647] U—Trimeperidine; arb.c.(0 1) = 0

1.           Urine—
3.    Cocaine;
4.           arbitrary concentration(procedure)     
7.           Authority: BAN
9.           [NPU01706]
10.          U—Cocaine; arb.c.(0 1) = 1
              deduced from
              Benzoylecgonine (CAS519-09-5)
              Ecgonine (CAS481-37-8)


c.           Ratio scale

1.           Plasma
3.    Fentanyl;
4.           substance concentration
5.           nanomole/litre  
9.           [NPU08918]
10.          P—Fentanyl; subst.c. = ? nmol/l

References

1.    Commission/Committee on Quantities and Units (in Clinical Chemistry) of the IUPAC–IFCC (International Union of Pure and Applied Chemistry– International Federation of Clinical Chemistry). Properties and units in the clinical laboratory sciences. I. Syntax and semantic rules. Prepared for publication by H Olesen. Pure & Appl Chem 1995; 67: 1563-74; Eur J Clin Chem Clin Biochem 1995; 33: 627-36; Clin Chim Acta 1996; 245: S5-S21.

2.    Commission/Committee on Quantities and Units (in Clinical Chemistry) of the IUPAC–IFCC (International Union of Pure and Applied Chemistry– International Federation of Clinical Chemistry). Properties and units in the clinical laboratory sciences. II. Kinds-of-property. Prepared for publication by D Kenny, H Olesen. Eur J Clin Chem Clin Biochem, 1997; 35: 317-44.

3.        IUPAC–IFCC (International Union of Pure and Applied Chemistry– International Federation of Clinical Chemistry), Commission-Committee on Nomenclature, Properties and Units. Properties and units in the clinical laboratory sciences. XI. Coding systems - structure and guidelines. (Technical report 1997). Prepared for publication by H Olesen, D Kenny, R Dybkęr, I Ibsen, I Bruunshuus, X Fuentes-Arderiu, G Hill, P Soares de Araujo, C McDonald. Pure and Appl Chem 1997; 35: 317-44.

4.        CEN/TC 251,1995. European Prestandard ENV 1614. Medical informatics. Structure for nomenclature, classification and coding of properties in clinical laboratory sciences.

5.        Dybkaer R. Vocabulary for use in measurement procedures and description of reference materials in laboratory medicine. Eur J Clin Chem Clin Biochem 1997; 35(2): 141-73.

6.        Duffus JH. Glossary for chemists of terms used in toxicology. Pure and Appl Chem 1993; 65: 2003-2122.

7.        CEN/TC 251, 1996. European Prestandard, ENV 12435. Medical informatics. Expression of the results of measurement in health sciences.

8.        WHO (World Health Organization). International Nonproprietary Names (INN) for Pharmaceutical Substances. Geneva: WHO.

9.        CAS (Chemical Abstracts Service) Registry Number.

10.    USAN (United States Adopted Name). 1961-1987 Cumulative List. List 147-289.

11.    BAN (British Approved Names) booklet, 1986, 1st, 2nd, 3rd, and 4th supplements.

12.    Reynolds EF (ed.), 1996. Martindale. The Extra Pharmacopoeia. 31st edition. London: The Pharmaceutical Press.

Index of Abbreviations

BAN    British Approved Name
CAS     Chemical Abstracts Service
IFCC    International Federation of Clinical Chemistry and Laboratory Medicine
INN      International Nonproprietary Names of WHO (approved)
*INN    for name to be approved
ISO       International Organization for Standardization
IUPAC  International Union of Pure and Applied Chemistry
USAN   United States Adopted Name
WHO    World Health Organization