Release 4

This page is part of the FHIR Specification (v4.0.1: R4 - Mixed Normative and STU) in it's permanent home (it will always be available at this URL). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3

Pharmacy Work GroupMaturity Level: 3Standards Status: Trial Use
Dosage
Standards StatusThis element has a standards status of "Trial Use"
Element IdDosage
Definition

Indicates how the medication is/was taken or should be taken by the patient.

Cardinality0..*
TypeBackboneElement
Summarytrue
Dosage.sequence
Element IdDosage.sequence
Definition

Indicates the order in which the dosage instructions should be applied or interpreted.

Cardinality0..1
Typeinteger
Requirements

If the sequence number of multiple Dosages is the same, then it is implied that the instructions are to be treated as concurrent. If the sequence number is different, then the Dosages are intended to be sequential.

Summarytrue
Dosage.text
Element IdDosage.text
Definition

Free text dosage instructions e.g. SIG.

Cardinality0..1
Typestring
Requirements

Free text dosage instructions can be used for cases where the instructions are too complex to code. The content of this attribute does not include the name or description of the medication. When coded instructions are present, the free text instructions may still be present for display to humans taking or administering the medication. It is expected that the text instructions will always be populated. If the dosage.timing attribute is also populated, then the dosage.text should reflect the same information as the timing. Additional information about administration or preparation of the medication should be included as text.

Summarytrue
Dosage.additionalInstruction
Element IdDosage.additionalInstruction
Definition

Supplemental instructions to the patient on how to take the medication (e.g. "with meals" or"take half to one hour before food") or warnings for the patient about the medication (e.g. "may cause drowsiness" or "avoid exposure of skin to direct sunlight or sunlamps").

Cardinality0..*
Terminology BindingSNOMED CT Additional Dosage Instructions (Example)
TypeCodeableConcept
Requirements

Additional instruction is intended to be coded, but where no code exists, the element could include text. For example, "Swallow with plenty of water" which might or might not be coded.

Summarytrue
Comments

Information about administration or preparation of the medication (e.g. "infuse as rapidly as possibly via intraperitoneal port" or "immediately following drug x") should be populated in dosage.text.

Dosage.patientInstruction
Element IdDosage.patientInstruction
Definition

Instructions in terms that are understood by the patient or consumer.

Cardinality0..1
Typestring
Summarytrue
Dosage.timing
Element IdDosage.timing
Definition

When medication should be administered.

Cardinality0..1
TypeTiming
Requirements

The timing schedule for giving the medication to the patient. This data type allows many different expressions. For example: "Every 8 hours"; "Three times a day"; "1/2 an hour before breakfast for 10 days from 23-Dec 2011:"; "15 Oct 2013, 17 Oct 2013 and 1 Nov 2013". Sometimes, a rate can imply duration when expressed as total volume / duration (e.g. 500mL/2 hours implies a duration of 2 hours). However, when rate doesn't imply duration (e.g. 250mL/hour), then the timing.repeat.duration is needed to convey the infuse over time period.

Summarytrue
Comments

This attribute might not always be populated while the Dosage.text is expected to be populated. If both are populated, then the Dosage.text should reflect the content of the Dosage.timing.

Dosage.asNeeded[x]
Element IdDosage.asNeeded[x]
Definition

Indicates whether the Medication is only taken when needed within a specific dosing schedule (Boolean option), or it indicates the precondition for taking the Medication (CodeableConcept).

Cardinality0..1
Terminology BindingSNOMED CT Medication As Needed Reason Codes (Example)
Typeboolean|CodeableConcept
[x] NoteSee Choice of Data Types for further information about how to use [x]
Summarytrue
Comments

Can express "as needed" without a reason by setting the Boolean = True. In this case the CodeableConcept is not populated. Or you can express "as needed" with a reason by including the CodeableConcept. In this case the Boolean is assumed to be True. If you set the Boolean to False, then the dose is given according to the schedule and is not "prn" or "as needed".

Dosage.site
Element IdDosage.site
Definition

Body site to administer to.

Cardinality0..1
Terminology BindingSNOMED CT Anatomical Structure for Administration Site Codes (Example)
TypeCodeableConcept
Requirements

A coded specification of the anatomic site where the medication first enters the body.

Summarytrue
Comments

If the use case requires attributes from the BodySite resource (e.g. to identify and track separately) then use the standard extension bodySite. May be a summary code, or a reference to a very precise definition of the location, or both.

Dosage.route
Element IdDosage.route
Definition

How drug should enter body.

Cardinality0..1
Terminology BindingSNOMED CT Route Codes (Example)
TypeCodeableConcept
Requirements

A code specifying the route or physiological path of administration of a therapeutic agent into or onto a patient's body.

Summarytrue
Dosage.method
Element IdDosage.method
Definition

Technique for administering medication.

Cardinality0..1
Terminology BindingSNOMED CT Administration Method Codes (Example)
TypeCodeableConcept
Requirements

A coded value indicating the method by which the medication is introduced into or onto the body. Most commonly used for injections. For examples, Slow Push; Deep IV.

Summarytrue
Comments

Terminologies used often pre-coordinate this term with the route and or form of administration.

Dosage.doseAndRate
Element IdDosage.doseAndRate
Definition

The amount of medication administered.

Cardinality0..*
Summarytrue
Dosage.doseAndRate.type
Element IdDosage.doseAndRate.type
Definition

The kind of dose or rate specified, for example, ordered or calculated.

Cardinality0..1
Terminology BindingDoseAndRateType (Example)
TypeCodeableConcept
Requirements

If the type is not populated, assume to be "ordered".

Summarytrue
Dosage.doseAndRate.dose[x]
Element IdDosage.doseAndRate.dose[x]
Definition

Amount of medication per dose.

Cardinality0..1
TypeRange|SimpleQuantity
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

The amount of therapeutic or other substance given at one administration event.

Summarytrue
Comments

Note that this specifies the quantity of the specified medication, not the quantity for each active ingredient(s). Each ingredient amount can be communicated in the Medication resource. For example, if one wants to communicate that a tablet was 375 mg, where the dose was one tablet, you can use the Medication resource to document that the tablet was comprised of 375 mg of drug XYZ. Alternatively if the dose was 375 mg, then you may only need to use the Medication resource to indicate this was a tablet. If the example were an IV such as dopamine and you wanted to communicate that 400mg of dopamine was mixed in 500 ml of some IV solution, then this would all be communicated in the Medication resource. If the administration is not intended to be instantaneous (rate is present or timing has a duration), this can be specified to convey the total amount to be administered over the period of time as indicated by the schedule e.g. 500 ml in dose, with timing used to convey that this should be done over 4 hours.

Dosage.doseAndRate.rate[x]
Element IdDosage.doseAndRate.rate[x]
Definition

Amount of medication per unit of time.

Cardinality0..1
TypeRatio|Range|SimpleQuantity
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

Identifies the speed with which the medication was or will be introduced into the patient. Typically the rate for an infusion e.g. 100 ml per 1 hour or 100 ml/hr. May also be expressed as a rate per unit of time e.g. 500 ml per 2 hours. Other examples: 200 mcg/min or 200 mcg/1 minute; 1 liter/8 hours. Sometimes, a rate can imply duration when expressed as total volume / duration (e.g. 500mL/2 hours implies a duration of 2 hours). However, when rate doesn't imply duration (e.g. 250mL/hour), then the timing.repeat.duration is needed to convey the infuse over time period.

Summarytrue
Comments

It is possible to supply both a rate and a doseQuantity to provide full details about how the medication is to be administered and supplied. If the rate is intended to change over time, depending on local rules/regulations, each change should be captured as a new version of the MedicationRequest with an updated rate, or captured with a new MedicationRequest with the new rate.

It is possible to specify a rate over time (for example, 100 ml/hour) using either the rateRatio and rateQuantity. The rateQuantity approach requires systems to have the capability to parse UCUM grammer where ml/hour is included rather than a specific ratio where the time is specified as the denominator. Where a rate such as 500ml over 2 hours is specified, the use of rateRatio may be more semantically correct than specifying using a rateQuantity of 250 mg/hour.

Dosage.maxDosePerPeriod
Element IdDosage.maxDosePerPeriod
Definition

Upper limit on medication per unit of time.

Cardinality0..1
TypeRatio
Requirements

The maximum total quantity of a therapeutic substance that may be administered to a subject over the period of time. For example, 1000mg in 24 hours.

Summarytrue
Comments

This is intended for use as an adjunct to the dosage when there is an upper cap. For example "2 tablets every 4 hours to a maximum of 8/day".

Dosage.maxDosePerAdministration
Element IdDosage.maxDosePerAdministration
Definition

Upper limit on medication per administration.

Cardinality0..1
TypeSimpleQuantity
Requirements

The maximum total quantity of a therapeutic substance that may be administered to a subject per administration.

Summarytrue
Comments

This is intended for use as an adjunct to the dosage when there is an upper cap. For example, a body surface area related dose with a maximum amount, such as 1.5 mg/m2 (maximum 2 mg) IV over 5 – 10 minutes would have doseQuantity of 1.5 mg/m2 and maxDosePerAdministration of 2 mg.

Dosage.maxDosePerLifetime
Element IdDosage.maxDosePerLifetime
Definition

Upper limit on medication per lifetime of the patient.

Cardinality0..1
TypeSimpleQuantity
Requirements

The maximum total quantity of a therapeutic substance that may be administered per lifetime of the subject.

Summarytrue