PRN dose limits

Two hard limits on PRN medications: minimum interval and maximum doses in 24 hours.

Every PRN medication can carry two safety limits, both enforced server-side at recording time:

The two limits

Limit

Field

Behaviour

Minimum interval

prn_min_interval_minutes

How long must pass between PRN doses. Blocks the recording if the previous PRN dose was too recent.

Max in 24 hours

prn_max_dose_24h

Count of administrations allowed in a rolling 24-hour window (NOT calendar day). Blocks the recording if reached.

Hard blocks, not soft warnings

Heads up — Both limits are hard blocks at the recorder. There is no "override" path in the standard PRN flow today. If a dose is genuinely needed despite the limit, contact the prescriber for a one-off authorisation — don't try to record around the system.

Rolling 24 hours

Both limits are calculated relative to the moment of recording — not to midnight. If you give a PRN at 23:45 and another at 01:00 the next "day", that's 1h15m apart, not "yesterday's + today's dose".

Last updated 21 May 2026 · by eMAR migration · Suggest a feature or change to this article
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