Medication prescription

This schema represents the prescription of a therapeutic agent, i.e., all the information specified by a physician pertaining a single medication in terms of route of administration and schedule for administration of every dose.

The schedule includes duration, frequency and timing.

• The schedule is an array indexed by the duration of dose(s).
• The duration of a prescription can be described with a length of time (e.g., 5 days) or can be continuing (in which case, duration is “99 years” so that we still use a time duration) or can be a calendar date or interval (e.g., a start date + a time duration) or a condition that applies.
• Such duration can be a length of time (e.g., 5 days), a range of time (e.g., 2-3 weeks) a time interval (e.g., between 3/11/2015 and 3/7/2015) or a condition (e.g., “until pain abates”).
• Each dose has a recurrence which may be described as a frequency (e.g., once a day, once every 4-6 hours), timing (e.g., at 9:00), or sequence (e.g., day 1).
• The timing defines the [combination of] part of day, day of week, time of day, temporal relationship to meals or sleep and time frame of such relationship (e.g., in the morning, on MWF, at 8:00, 30 minutes before breakfast).
• The sequence defines the position on a timeline (e.g., day 1).

The prescription is first used by the pharmacy to dispense the medication and then applied by the person to his/her daily schedule.
The schema applies the closed-world assumption. For example, if a therapeutic agent is prescribed for twice every 5 days (frequency) on day 1 and day 3, the schema models those days, but not day 2, 4 and 5 when no dose occurs.