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

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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

HIQA EP 5.2.1 Sequence (Optional; when there is more than one dosaging scheme). Consecutive schemes take increasing numbers (1, 2, 3); schemes that apply at the same time share a number.

EHDSDosage

Free text dosage instructions e.g. SIG.

HIQA EP 5.1 Rendered dosage instruction. Always the full instruction a person would read, even when the dosage is structured (ie-dos-1).

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.

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").

Supplementary instructions or warnings, coded in SNOMED CT where possible (e.g. 311504000 |With or after food|, 421984009 |Until finished|).

A coded concept identifying additional instructions such as "take with water" or "avoid operating heavy machinery".

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.

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

HIQA EP 5.2.2 Note for patient (Required): instructions in plain language for the patient.

EHDSDosage

When medication should be administered.

HIQA EP 5.2.4 Repeat administration of medication item (Required).

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.

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

A set of rules that describe when the event is scheduled.

EHDSDosage

Either a duration for the length of the timing schedule, a range of possible length, or outer bounds for start and/or end limits of the timing schedule.

HIQA EP 5.2.4.1 Time bounds: a duration (5.2.4.1.1, e.g. 5 days) or a period with dates (5.2.4.1.2).

EHDSDosage

How long this thing happens for when it happens. If durationMax is present, this element indicates the lower bound of the allowed range of the duration.

HIQA EP 5.2.4.2 Duration of administration (e.g. an infusion over 30 minutes), with durationUnit.

EHDSDosage

The number of times to repeat the action within the specified period. If frequencyMax is present, this element indicates the lower bound of the allowed range of the frequency.

HIQA EP 5.2.4.3.1 Frequency of administration (Mandatory within the frequency cluster): how many times per period.

EHDSDosage

Indicates the duration of time over which repetitions are to occur; e.g. to express "3 times per day", 3 would be the frequency and "1 day" would be the period. If periodMax is present, this element indicates the lower bound of the allowed range of the period length.

HIQA EP 5.2.4.3.2 Period (Mandatory within the frequency cluster), with periodUnit (ie-dos-2).

EHDSDosage

The units of time for the period in UCUM units.

A unit of time (units from UCUM).

EHDSDosage

If one or more days of week is provided, then the action happens only on the specified day(s).

HIQA EP 5.2.4.4 Day of the week (Optional), e.g. a weekly medicine taken on Mondays.

EHDSDosage

Specified time of day for action to take place.

HIQA EP 5.2.4.5 Time of the day (Optional).

EHDSDosage

An approximate time period during the day, potentially linked to an event of daily living that indicates when the action should occur.

HIQA EP 5.2.4.6 Event or time period for administration (Optional), e.g. ACM before breakfast, HS at bedtime; offset in minutes.

Real world event relating to the schedule.

EHDSDosage

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).

HIQA EP 5.2.5 Administer as needed (Optional). HL7 Europe MPD allows only asNeededBoolean, so the reason (e.g. for wheeze) is given in text and patientInstruction; give a maximum dose per period (ie-dos-3).

A coded concept identifying the precondition that should be met or evaluated prior to consuming or administering a medication dose. For example "pain", "30 minutes prior to sexual intercourse", "on flare-up" etc.

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).

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".

EHDSDosage

Body site to administer to.

HIQA EP 5.2.6 Body site or structure (Optional): morphology, location, qualifier and laterality post-coordinated in SNOMED CT, or free text in site.text (5.2.6.5).

A coded concept describing the site location the medicine enters into or onto the body.

EHDSDosage

How drug should enter body.

HIQA EP 5.2.7 Route of administration (Required). SNOMED CT route concepts (e.g. 26643006 |Oral route|); EDQM Standard Terms when bound (Requires Clarification).

A coded concept describing the route or physiological path of administration of a therapeutic agent into or onto the body of a subject.

EHDSDosage

Technique for administering medication.

The technique of administration (e.g. inhale, apply); SNOMED CT.

A coded concept describing the technique by which the medicine is administered.

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.

The amount of medication administered.

HIQA EP 5.2.3 Dose and rate (Required).

EHDSDosage

Amount of medication per dose.

HIQA EP 5.2.3.1 Dose of medication item: a quantity (5.2.3.1.1) or a range (5.2.3.1.2). Product-based doses use a SNOMED CT unit of presentation (e.g. 732936001 |Tablet|); strength-based doses use UCUM (e.g. mg, [iU]). Both ends of a range are given (ie-dos-4).

EHDSDosage

Amount of medication per unit of time.

HIQA EP 5.2.3.2 Rate of administration (Optional): a quantity (5.2.3.2.1, e.g. mL/h) or a ratio (5.2.3.2.2).

EHDSDosage

Upper limit on medication per unit of time.

Maximum dose per period (e.g. 8 actuations in 24 hours). Not a distinct HIQA element; expected with as-needed dosing (ie-dos-3).

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.

Upper limit on medication per administration.

Maximum dose per administration.

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

HIQA EP 5.2.1 Sequence (Optional; when there is more than one dosaging scheme). Consecutive schemes take increasing numbers (1, 2, 3); schemes that apply at the same time share a number.

HIQA EP 5.1 Rendered dosage instruction. Always the full instruction a person would read, even when the dosage is structured (ie-dos-1).

Supplementary instructions or warnings, coded in SNOMED CT where possible (e.g. 311504000 |With or after food|, 421984009 |Until finished|).

HIQA EP 5.2.2 Note for patient (Required): instructions in plain language for the patient.

HIQA EP 5.2.4 Repeat administration of medication item (Required).

HIQA EP 5.2.4.1 Time bounds: a duration (5.2.4.1.1, e.g. 5 days) or a period with dates (5.2.4.1.2).

HIQA EP 5.2.4.2 Duration of administration (e.g. an infusion over 30 minutes), with durationUnit.

HIQA EP 5.2.4.3.1 Frequency of administration (Mandatory within the frequency cluster): how many times per period.

HIQA EP 5.2.4.3.2 Period (Mandatory within the frequency cluster), with periodUnit (ie-dos-2).

HIQA EP 5.2.4.4 Day of the week (Optional), e.g. a weekly medicine taken on Mondays.

HIQA EP 5.2.4.5 Time of the day (Optional).

HIQA EP 5.2.4.6 Event or time period for administration (Optional), e.g. ACM before breakfast, HS at bedtime; offset in minutes.

HIQA EP 5.2.5 Administer as needed (Optional). HL7 Europe MPD allows only asNeededBoolean, so the reason (e.g. for wheeze) is given in text and patientInstruction; give a maximum dose per period (ie-dos-3).

HIQA EP 5.2.6 Body site or structure (Optional): morphology, location, qualifier and laterality post-coordinated in SNOMED CT, or free text in site.text (5.2.6.5).

HIQA EP 5.2.7 Route of administration (Required). SNOMED CT route concepts (e.g. 26643006 |Oral route|); EDQM Standard Terms when bound (Requires Clarification).

The technique of administration (e.g. inhale, apply); SNOMED CT.

HIQA EP 5.2.3 Dose and rate (Required).

HIQA EP 5.2.3.1 Dose of medication item: a quantity (5.2.3.1.1) or a range (5.2.3.1.2). Product-based doses use a SNOMED CT unit of presentation (e.g. 732936001 |Tablet|); strength-based doses use UCUM (e.g. mg, [iU]). Both ends of a range are given (ie-dos-4).

HIQA EP 5.2.3.2 Rate of administration (Optional): a quantity (5.2.3.2.1, e.g. mL/h) or a ratio (5.2.3.2.2).

Maximum dose per period (e.g. 8 actuations in 24 hours). Not a distinct HIQA element; expected with as-needed dosing (ie-dos-3).

Maximum dose per administration.

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

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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

HIQA EP 5.2.1 Sequence (Optional; when there is more than one dosaging scheme). Consecutive schemes take increasing numbers (1, 2, 3); schemes that apply at the same time share a number.

EHDSDosage

Free text dosage instructions e.g. SIG.

HIQA EP 5.1 Rendered dosage instruction. Always the full instruction a person would read, even when the dosage is structured (ie-dos-1).

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.

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").

Supplementary instructions or warnings, coded in SNOMED CT where possible (e.g. 311504000 |With or after food|, 421984009 |Until finished|).

A coded concept identifying additional instructions such as "take with water" or "avoid operating heavy machinery".

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.

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

HIQA EP 5.2.2 Note for patient (Required): instructions in plain language for the patient.

EHDSDosage

When medication should be administered.

HIQA EP 5.2.4 Repeat administration of medication item (Required).

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.

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Identifies specific times when the event occurs.

In a Medication Administration Record, for instance, you need to take a general specification, and turn it into a precise specification.

A set of rules that describe when the event is scheduled.

EHDSDosage

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Either a duration for the length of the timing schedule, a range of possible length, or outer bounds for start and/or end limits of the timing schedule.

HIQA EP 5.2.4.1 Time bounds: a duration (5.2.4.1.1, e.g. 5 days) or a period with dates (5.2.4.1.2).

EHDSDosage

A total count of the desired number of repetitions across the duration of the entire timing specification. If countMax is present, this element indicates the lower bound of the allowed range of count values.

If you have both bounds and count, then this should be understood as within the bounds period, until count times happens.

Repetitions may be limited by end time or total occurrences.

If present, indicates that the count is a range - so to perform the action between [count] and [countMax] times.

How long this thing happens for when it happens. If durationMax is present, this element indicates the lower bound of the allowed range of the duration.

HIQA EP 5.2.4.2 Duration of administration (e.g. an infusion over 30 minutes), with durationUnit.

EHDSDosage

If present, indicates that the duration is a range - so to perform the action between [duration] and [durationMax] time length.

For some events the duration is part of the definition of the event (e.g. IV infusions, where the duration is implicit in the specified quantity and rate). For others, it's part of the timing specification (e.g. exercise).

Some activities are not instantaneous and need to be maintained for a period of time.

The units of time for the duration, in UCUM units.

A unit of time (units from UCUM).

EHDSDosage

The number of times to repeat the action within the specified period. If frequencyMax is present, this element indicates the lower bound of the allowed range of the frequency.

HIQA EP 5.2.4.3.1 Frequency of administration (Mandatory within the frequency cluster): how many times per period.

EHDSDosage

If present, indicates that the frequency is a range - so to repeat between [frequency] and [frequencyMax] times within the period or period range.

Indicates the duration of time over which repetitions are to occur; e.g. to express "3 times per day", 3 would be the frequency and "1 day" would be the period. If periodMax is present, this element indicates the lower bound of the allowed range of the period length.

HIQA EP 5.2.4.3.2 Period (Mandatory within the frequency cluster), with periodUnit (ie-dos-2).

EHDSDosage

If present, indicates that the period is a range from [period] to [periodMax], allowing expressing concepts such as "do this once every 3-5 days.

The units of time for the period in UCUM units.

A unit of time (units from UCUM).

EHDSDosage

If one or more days of week is provided, then the action happens only on the specified day(s).

HIQA EP 5.2.4.4 Day of the week (Optional), e.g. a weekly medicine taken on Mondays.

EHDSDosage

Specified time of day for action to take place.

HIQA EP 5.2.4.5 Time of the day (Optional).

EHDSDosage

An approximate time period during the day, potentially linked to an event of daily living that indicates when the action should occur.

HIQA EP 5.2.4.6 Event or time period for administration (Optional), e.g. ACM before breakfast, HS at bedtime; offset in minutes.

Real world event relating to the schedule.

EHDSDosage

The number of minutes from the event. If the event code does not indicate whether the minutes is before or after the event, then the offset is assumed to be after the event.

A code for the timing schedule (or just text in code.text). Some codes such as BID are ubiquitous, but many institutions define their own additional codes. If a code is provided, the code is understood to be a complete statement of whatever is specified in the structured timing data, and either the code or the data may be used to interpret the Timing, with the exception that .repeat.bounds still applies over the code (and is not contained in the code).

BID etc. are defined as 'at institutionally specified times'. For example, an institution may choose that BID is "always at 7am and 6pm". If it is inappropriate for this choice to be made, the code BID should not be used. Instead, a distinct organization-specific code should be used in place of the HL7-defined BID code and/or a structured representation should be used (in this case, specifying the two event times).

Code for a known / defined timing pattern.

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).

HIQA EP 5.2.5 Administer as needed (Optional). HL7 Europe MPD allows only asNeededBoolean, so the reason (e.g. for wheeze) is given in text and patientInstruction; give a maximum dose per period (ie-dos-3).

A coded concept identifying the precondition that should be met or evaluated prior to consuming or administering a medication dose. For example "pain", "30 minutes prior to sexual intercourse", "on flare-up" etc.

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).

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".

EHDSDosage

Body site to administer to.

HIQA EP 5.2.6 Body site or structure (Optional): morphology, location, qualifier and laterality post-coordinated in SNOMED CT, or free text in site.text (5.2.6.5).

A coded concept describing the site location the medicine enters into or onto the body.

EHDSDosage

How drug should enter body.

HIQA EP 5.2.7 Route of administration (Required). SNOMED CT route concepts (e.g. 26643006 |Oral route|); EDQM Standard Terms when bound (Requires Clarification).

A coded concept describing the route or physiological path of administration of a therapeutic agent into or onto the body of a subject.

EHDSDosage

Technique for administering medication.

The technique of administration (e.g. inhale, apply); SNOMED CT.

A coded concept describing the technique by which the medicine is administered.

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.

The amount of medication administered.

HIQA EP 5.2.3 Dose and rate (Required).

EHDSDosage

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

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

The kind of dose or rate specified.

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

Amount of medication per dose.

HIQA EP 5.2.3.1 Dose of medication item: a quantity (5.2.3.1.1) or a range (5.2.3.1.2). Product-based doses use a SNOMED CT unit of presentation (e.g. 732936001 |Tablet|); strength-based doses use UCUM (e.g. mg, [iU]). Both ends of a range are given (ie-dos-4).

EHDSDosage

Amount of medication per unit of time.

HIQA EP 5.2.3.2 Rate of administration (Optional): a quantity (5.2.3.2.1, e.g. mL/h) or a ratio (5.2.3.2.2).

EHDSDosage

Upper limit on medication per unit of time.

Maximum dose per period (e.g. 8 actuations in 24 hours). Not a distinct HIQA element; expected with as-needed dosing (ie-dos-3).

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.

Upper limit on medication per administration.

Maximum dose per administration.

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

Upper limit on medication per lifetime of the patient.

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