Skip to content

Medicine store: how long does it last, and when should it be ordered

How many days will the packaging last, and when should I order?

Answer: With residents where you dispense from packages new medicine must be ordered before it runs out. Calculator divides stock by prescribed amount per day and subtracts pharmacy delivery time and safety margin so you see days before latest ordering time. Calculates only regular medicine. PN medicine and changes in prescription you handle yourself.

Formula

Beholdningen rækker (hele døgn) = beholdning ÷ ordineret antal pr. døgn, rundet ned

Bestil senest om (dage) = døgn beholdningen rækker − leveringstid − sikkerhedsmargin (mindst 0)

Eksempel: 98 tabletter ÷ 3 pr. døgn = 32 hele døgn. Med 3 dages levering og 2 dages margin skal der bestilles senest om 27 dage

Symbols and units in the formula
SymbolMeaningUnit
beholdningTablets or units in stockstk
pr_doegnOrdered amount per daystk/døgn
leveringDelivery time from pharmacydage
bufferSafety margin (weekend, holidays)dage
=Order latest bydage
=The stock lasts (full 24 hours)døgn
=Consumption per weekstk

Validity and source

Source
Rule of three for medicine handling (stock and reordering)

Does not apply when

  • Count inventory when dispensing so the number matches. Medication dispensed from the pharmacy follows its own delivery rhythm. Follow the workplace instructions for ordering and speak to the nurse if consumption does not match the prescription.

Worked example

The calculator's own default values inserted. The figures are calculated with exactly the formula the tool uses.

Substituted

  • Tablets or units in stock98 stk
  • Ordered amount per day3 stk/døgn
  • Delivery time from pharmacy3 dage
  • Safety margin (weekend, holidays)2 dage

Giver

  • Order latest by27 dage
  • The stock lasts (full 24 hours)32 døgn
  • Consumption per week21.0 stk

The calculator itself is locked

Create a free user account to unlock all articles, calculators, templates and range — and get access to quizzes and classes. It takes less than a minute: name, email and a password. No payment card.

Want to try something first? See what you can use without an account — the junior zone, the encyclopedia, the videos and more.

Sådan bruger du den

Hos borgere, hvor I selv dispenserer medicin, skal du sørge for, at der bestilles i tide. Beregneren viser, hvor mange døgn beholdningen rækker, og hvornår der senest skal bestilles, når apotekets leveringstid og en sikkerhedsmargin er trukket fra.

Step by step

  1. Tæl beholdningen, når du dispenserer.
  2. Find det ordinerede antal pr. døgn i medicinlisten.
  3. Del beholdningen med antallet pr. døgn.
  4. Træk leveringstiden og en margin fra. Så har du antal dage, til der skal bestilles.
  5. Skriv datoen i borgerens plan.

Typical errors

  • At glemme helligdage og weekender.
  • At regne med en gammel ordination.
  • At glemme PN-medicin.

Examples from everyday life

Fast medicin tre gange dagligt

En borger har 98 tabletter og tager 3 om dagen. Apoteket leverer på 3 dage, og I har en margin på 2 dage.

Tablets or units in stock
98 pcs
Ordered amount per day
3 stk/døgn
Delivery time from pharmacy
3 days
Safety margin (weekend, holidays)
2 days

It means: Beholdningen rækker 32 24 hours, og der skal bestilles senest om 27 days. Forbruget er 21 pcs om ugen.

Lille pakning

En borger har 28 tabletter og tager 2 om dagen. Levering 3 dage, margin 2 dage.

Tablets or units in stock
28 pcs
Ordered amount per day
2 stk/døgn
Delivery time from pharmacy
3 days
Safety margin (weekend, holidays)
2 days

It means: Beholdningen rækker 14 24 hours, og der skal bestilles senest om 9 days.

Halv tablet om dagen

En borger tager en halv tablet om dagen og har 10 tabletter tilbage.

Tablets or units in stock
10 pcs
Ordered amount per day
0.5 stk/døgn
Delivery time from pharmacy
3 days
Safety margin (weekend, holidays)
2 days

It means: De rækker 20 24 hours, og der skal bestilles senest om 15 days.

Rule of thumb

Bestil, når der er en uge tilbage.

How to check the answer

Gang døgnene med antallet pr. døgn. Det skal være lig med eller lidt mindre end beholdningen.