Doses

The Doses Administered tab records every dose the patient actually received during the episode. It’s the first thing to fill in — concentrations and estimation both depend on at least one dose existing.

Recorded doses for an episode.

Adding a dose

Select Add dose and fill in:

Field	Notes
Date & time	When the dose was given.
Amount	In the drug’s dosing unit (e.g. mg).
Infusion time	Only shown for drugs administered by perfusion. The infusion rate is calculated automatically as amount ÷ infusion time. Bolus drugs don’t show this field.

Adding a dose to a perfusion drug, with infusion time.

Repeating doses

Enable Additional doses to generate a series of repeating doses at once, instead of adding each one individually:

• Interval — hours between doses.
• Number of additional doses — how many more doses to generate after the first.

The dialog previews the generated schedule live before you save it:

Live preview of a repeating dose schedule.

Tip

Doses can be edited or deleted afterward from the table — reopen a row to correct a mistyped amount or time.

Caution

The first dose of an episode can’t be deleted once concentrations or covariates depend on it — PKPDrugs uses it as the reference point for validating those dates (see Concentrations and Covariates). If you need to remove it, delete the dependent concentrations/covariates first, or delete the whole episode instead if it was created by mistake.

Fields, checks and limits

Add or edit a dose

Field	What to enter	Unit	Required	Minimum	Maximum	Message you see if it is wrong
Date	Day the dose was given.	Date	Yes	-	No limit is checked	“Date is required”
Time	Time of day the dose was given.	Hours and minutes	Yes	-	No limit is checked	“Time is required”
Amount	The dose actually given.	The drug’s dosing unit (shown next to the field, mg if none is set)	Yes	Greater than 0	1,000,000	“Amount must be a positive number”
Infusion time	How long the infusion lasted. Shown only for drugs given by perfusion. PKPDrugs calculates the rate as amount divided by infusion time.	Hours	Yes, for perfusion drugs	Greater than 0	1,000,000	“Infusion duration must be a positive number”
Additional doses (switch)	Turn on to create a series of repeated doses.	On or off	No	-	-	-
Interval	Time between one dose and the next. Only used when the switch is on.	Hours	Yes, if the switch is on	Greater than 0	1,000,000	“Interval must be a positive number”
Number of additional doses	How many extra doses follow the first. Whole number.	Doses	Yes, if the switch is on	1	1,000,000	“Number of additional doses must be a positive integer”

About the maximum of 1,000,000. For amount, infusion time and interval, the form shows a red hint (“Must be between 0 and 1000000”) when you type a larger value, but it does not stop you from saving. The database refuses an amount, an interval or an infusion rate above 1,000,000, and then you see only a general “Failed to add dose” message. The infusion time and the number of additional doses have no limit on the server.

The server repeats the main checks, in case a dose comes from another route. It also requires that interval and number of additional doses go together: both above zero, or both zero. A series needs both, because an interval with no repeats (or repeats with no interval) cannot describe a schedule. The messages are:

• “The amount must be greater than zero. The compartment and the rate cannot be negative.”
• “Infusion time must be positive.” (only for a drug given by perfusion; a bolus or an oral dose needs no infusion time)
• “The interval and the number of additional doses must both be greater than zero, or both be zero.”

A dose date in the future is not blocked. Enter only doses that were really given, because estimation treats every dose as given.

What is new in 2026.11

The server now answers dose problems with a readable sentence (the three messages above). Before, a rejected dose could return a general failure message with no reason.

Possible errors

Message	What it means	What to do
Amount must be a positive number	The dose amount is zero, negative, or not a number.	Enter a value greater than 0 in the drug’s dosing unit.
Infusion duration must be a positive number	The infusion time field (perfusion drugs only) is zero, negative, or missing.	Enter a value greater than 0 — this is what the infusion rate is calculated from.
Interval must be a positive number	The repeat interval for additional doses is zero, negative, or missing.	Enter the number of hours between repeated doses.
Number of additional doses must be a positive integer	The additional-doses count is zero, negative, or not a whole number.	Enter a whole number of extra doses to generate.
The first dose cannot be deleted because there are dependent concentrations or covariates	See the note above.	Remove the dependent concentration/covariate records first, or delete the episode if it’s not needed.
Failed to add/update/delete dose	The request reached the server but failed.	Retry; if it persists, check your network connection or contact an administrator.

Next: Concentrations.