PRN medication protocols: how to write a PRN protocol inspectors accept

A PRN medication protocol is a short, person-specific document that tells care staff exactly when to give a medicine prescribed as required, how much to give, how long to wait between doses, what to try before reaching for it, what to write down and when to call for help. Every PRN medicine on every MAR chart should have one. It is the difference between a worker making a judgement the prescriber anticipated and a worker guessing.

The short answer

PRN stands for pro re nata, which means as the situation demands. The prescriber writes the medicine up with a dose range and a maximum, and leaves the decision about each dose to the home. That decision needs a framework. A good PRN protocol has nine parts: the medicine and dose, what it is for in plain language, how the person shows they need it, what to try first, the minimum gap and the daily maximum, what to record, when to review the effect, when to escalate, and who signed it off and when. Write one for each PRN medicine for each person, keep it with the MAR chart or attached to the medicine on the eMAR, and review it whenever the prescription or the person changes. The rest of this guide takes each part in turn and shows what it looks like in practice.

What PRN means and why a protocol is needed

Regular medicines are given at set times and the worker's job is to give them correctly. PRN medicines are different. The prescriber has decided that the person may need paracetamol for pain, or a laxative for constipation, or lorazepam for acute distress, but not when. That judgement passes to whoever is on shift.

In a hospital, a nurse makes that call with training and a doctor nearby. In a care home, the person making it may be a senior carer at two in the morning with nobody to ask. The protocol is how the prescriber's intention reaches that worker. It is also how the home shows, afterwards, that the dose was given for the right reason, at the right time, and that the outcome was checked.

Without a protocol, PRN medicines drift. Paracetamol is given because the person looks uncomfortable, or is not given because the worker was not sure. Sedatives are given because the shift is short-staffed. A laxative is never given because nobody is watching the bowel chart. None of that is malicious. All of it is what happens when the decision has no structure.

At a glance: what a PRN protocol must contain

What NICE SC1 and the CQC medication administration guidelines expect

NICE guideline SC1 on managing medicines in care homes says that care home staff should have clear processes for when-required medicines, including the reason for the medicine, how much to give and when, how to decide whether it is needed, the maximum dose in a day, and how to record the effect. It is one short paragraph in the guideline and it is the basis for everything in this article.

CQC's guidance on medicines in adult social care makes the same points from the inspection side. Inspectors will pick a PRN medicine on a MAR chart, ask to see the protocol, check that the doses recorded match it, and ask a worker how they decide. If the protocol is missing, generic, or contradicts the prescription, that is a finding under the safe key question. If PRN use is high and there is no evidence of review, that is a finding too.

The guideline does not prescribe a form. Any layout that covers the elements is acceptable. What matters is that it is specific to the person and the medicine, current, and available to the worker at the moment they need it.

Who writes the protocol and who signs it

The prescriber sets the medicine, the dose, the interval and the maximum, and those parts of the protocol must match the prescription exactly. The home writes the rest: how this person shows they need it, what to try first, what to record. The best protocols are written together, with the GP or pharmacist confirming the clinical parts and the keyworker or nurse writing the person-specific parts.

In practice, the home usually drafts it and asks the prescriber or the pharmacist to check it. Some GP practices will sign PRN protocols; many will not, and that is not a barrier. What the inspector wants to see is that the clinical content came from the prescription and that a named person in the home took responsibility for the document. The registered manager or the nurse in charge signs it, dates it, and sets a review date. The person, or their representative, is involved wherever possible, because the protocol describes them.

The medicine, the form and the dose

Start with the prescription. Copy the medicine name, strength, form and route exactly. If the prescription says paracetamol 500mg tablets, one or two tablets, up to four times a day, the protocol says the same. It does not say two tablets because that is what she usually has. If the prescription allows a range, the protocol explains how to choose: one tablet for mild pain, two for moderate, or start with one and give a second after an hour if no better, whichever the prescriber intended.

Note anything about the form that matters. Liquid morphine is measured in millilitres with an oral syringe. A buccal preparation goes between the gum and the cheek. A suppository needs a different consent conversation. If the medicine is also given regularly, say so, because the PRN dose counts toward the daily maximum. A person on regular paracetamol four times a day has no room for a PRN dose, and the protocol must say so.

The indication, in the person's words

The indication is what the medicine is for. The prescription will say something clinical: pain, anxiety, constipation, agitation. The protocol should say it in a way that describes this person. Not agitation but: when Tom is pacing the corridor, refusing to sit, and hitting his head with his hand. Not pain but: when Margaret holds her left knee and will not put weight on it, or says her leg is bad.

This matters because the worker on shift is looking at a person, not a diagnosis. A protocol that says agitation gives them nothing. A protocol that describes what agitation looks like for Tom lets them recognise it, and lets a reviewer afterwards check that what was recorded matches what was described. The person themselves, where they can, should tell you how they know they need the medicine and what words they use for it.

Signs the person needs it when they cannot tell you

Many people in learning disability, dementia and mental health services cannot reliably say they are in pain or distressed. The protocol has to give the worker something to look for. Draw on the care plan, the hospital passport, the family and the person's own history. Pain in someone who cannot speak might show as a change in facial expression, guarding, rocking, refusing food, sleeping badly, or a rise in behaviour that challenges. A validated pain tool such as the Abbey Pain Scale or PAINAD can be named in the protocol and used before each dose.

Constipation might show as restlessness, reduced appetite, a distended abdomen, or the bowel chart showing no movement for three days. Distress might show as the early signs listed in the person's positive behaviour support plan. The protocol says what to look for, and it says what the worker should rule out first: is he in pain rather than distressed, is she constipated rather than agitated, is the room too hot, is he hungry.

What to try first

The least restrictive option always comes first. For pain, that might be repositioning, a heat pad, a distraction, or checking whether the regular analgesia was actually given. For distress, it is whatever the PBS plan says works: a quiet space, a familiar activity, a walk, a particular member of staff, a drink. For sleep, it is checking the room, the noise, the caffeine, the daytime activity. For constipation, it is fluids, fibre, movement and toileting routine before the laxative.

The protocol lists these, briefly, and asks the worker to record what was tried. That record is what shows, later, that the medicine was not the first response. It also builds the evidence for reducing PRN use, because if the non-drug approaches work most of the time, the prescriber can see that.

Where the medicine is a sedative used in crisis, this section is the most important one in the document, and it must align exactly with the reactive strategies in the positive behaviour support plan. Two documents giving different advice at the moment of crisis is dangerous.

Minimum interval and maximum in 24 hours

The prescription sets these and the protocol repeats them in plain words. Paracetamol: at least four hours between doses, no more than four doses in twenty-four hours, counting any regular doses. Lorazepam: as prescribed, often no more than two doses in twenty-four hours, with a stated gap. Codeine: as prescribed, with a warning about constipation and drowsiness.

Say what twenty-four hours means. A rolling window from the first dose, not a calendar day, is usual and is what prevents a worker giving the maximum at eleven at night and again at one in the morning. If the home uses an eMAR, the system enforces the interval; on paper, the protocol tells the worker to check the last dose time before giving another.

Where two PRN medicines have the same indication, for example paracetamol and codeine for pain, the protocol says which comes first and whether both may be given. Where a PRN medicine interacts with a regular one, say so.

What to record before, during and after

The record has four parts. Before the dose: what the person showed, what was tried, and why the worker decided the medicine was needed. At the dose: the time, the exact amount, the route, and who gave it, with a witness for a controlled drug. After the dose: at a set interval, usually thirty to sixty minutes, whether it worked, using the same signs as before. And the running count: how many doses so far in the window.

On a paper MAR chart, the dose goes in the box with the time and quantity, and the reason and outcome go on the reverse or in the daily notes. On an eMAR, the protocol is attached to the medicine, the reason is chosen or typed at the point of administration, and the system prompts for the outcome. Either way, the test is whether a reviewer could reconstruct the decision from the record alone. The guide to MAR chart codes covers how PRN entries sit alongside the codes for refused and not required.

When to escalate

The protocol tells the worker when the medicine is not enough. If the dose does not work after the review interval, what next: a second dose if allowed, or a call to the GP, 111 or 999. If the person is needing the maximum every day for a week, the manager should hear about it, and the prescriber should be asked to review. If a sedative is being used more than a set number of times in a month, the PBS lead and the prescriber review together.

Give thresholds, not just instructions. Three doses of PRN lorazepam in a week triggers a review. Paracetamol needed every day for a fortnight means the pain is not being managed and the regular analgesia should be looked at. A laxative given more than twice a week means the bowel care plan is not working. The thresholds turn PRN use from a series of individual decisions into a signal the home can act on.

A worked example: paracetamol for pain

Margaret is 84, has osteoarthritis in both knees, and is prescribed paracetamol 500mg tablets, one or two, up to four times a day, as required. She can tell you when her knees hurt. Her protocol reads something like this.

Paracetamol 500mg tablets, one or two tablets by mouth, as required for knee pain. Minimum four hours between doses. No more than eight tablets in any twenty-four hours. Margaret will usually say her knees are bad, or rub them, or refuse to walk to the dining room. Before giving, offer a change of position, the heat pad on her knees for twenty minutes, and check she is not sitting with her legs down for long periods. If she still has pain, give two tablets with a drink. Record the time, the dose, what she said and what was tried. Check with her after an hour and record whether the pain has eased. If she needs paracetamol every day for two weeks, tell the manager so the GP can review regular pain relief. If the pain is new, severe, or in a different place, contact the GP the same day.

That is the whole thing. It is specific, it is short, and any worker could follow it.

A worked example: lorazepam under a PBS plan

Tom is 29, has a learning disability and autism, and lives in a small supported home. He is prescribed lorazepam 1mg tablets, one tablet as required for severe distress, maximum two doses in twenty-four hours, at least four hours apart. He cannot reliably say how he feels. His protocol is tied to his PBS plan.

Lorazepam 1mg, one tablet by mouth, as required for severe distress only. Severe distress for Tom means he has moved past the amber signs in his PBS plan (pacing, hand-flapping, repeating the same phrase) into red: hitting his own head, attempting to hit others, or trying to leave the building without support. Before giving, use every amber strategy in the PBS plan: reduce noise, one staff member only, offer the sensory room, offer his headphones, do not ask questions. Do not give lorazepam for amber signs. Only give it if red signs continue after fifteen minutes of amber strategies and Tom is at risk of hurting himself or others. Record the antecedent, the behaviour, the strategies used, the time and the dose. Review after thirty minutes and record what changed. Complete an ABC chart for the incident in the daily log. Any dose is reported to the manager the same day. Three doses in a month triggers a review with the PBS lead and the prescriber. Tom lacks capacity to consent to this medicine; the best interests decision dated in his care plan applies, and the decision is reviewed with the protocol.

PRN and the positive behaviour support plan

Where a PRN medicine is used for distress or behaviour, the protocol and the PBS plan are two views of the same thing. The PBS plan describes the person's behaviour, its function, the primary strategies that reduce the need for it, the secondary strategies for early signs, and the reactive strategies for crisis. The PRN protocol sits in the reactive strategies, as the last step, with everything else tried first.

The two documents must say the same thing about when the medicine is used. The ABC charts completed after each incident, and the PRN record, are read together at review. If the medicine is being given at amber, the PBS plan is not being followed. If it is being given more often, the primary strategies are not working and the plan needs to change. The ABC chart guide covers how to record incidents so that pattern shows.

PRN, capacity, consent and covert administration

Every PRN dose is an offer of a medicine, and the person's consent matters. Where the person has capacity, the protocol says how the medicine is offered and records that they accepted or refused. Refusal is respected and recorded. Where the person lacks capacity for that decision, a best interests decision is made under the Mental Capacity Act 2005, recorded in the care plan, and the protocol refers to it.

Covert administration of a PRN medicine, hidden in food or drink, is unusual and needs the same process as any covert medicine: a capacity assessment for that decision, a best interests meeting involving the prescriber and the pharmacist, confirmation that the medicine can be given that way, a record in the care plan, and a review date. A PRN sedative given covertly to someone who is distressed is close to chemical restraint, and the home must be able to show it was the least restrictive option available. Where the person is under DoLS, the conditions may say something specific.

Homely remedies are not PRN medicines

A homely remedy is a medicine the home stocks and gives without a prescription for minor ailments, such as paracetamol for a headache or a simple antacid, under a policy agreed with the GP or pharmacist. It is not a PRN medicine, because it is not prescribed for the person. It has its own rules: a list agreed by the prescriber, a maximum duration, a check that it does not clash with prescribed medicines, and a record.

The confusion arises when a person has paracetamol prescribed as required and the home also holds paracetamol as a homely remedy. The protocol for the prescribed PRN applies, and the homely remedy is not used for that person for that indication. The medicines policy should set out the difference and the homely remedies list should be reviewed with the pharmacist at least yearly.

Recording PRN on the MAR chart and the eMAR

PRN medicines are on the MAR chart like any other, but most of the boxes will be empty because most of the time the medicine is not given. That is where paper charts go wrong. An empty box on a regular medicine means missed medication; an empty box on a PRN means not needed; and the chart cannot tell the difference. Use a code for PRN not required, or a line through the box, so that nothing is blank.

When a dose is given, the box shows the time and the exact quantity, not just initials. Two tablets recorded as one dose is a stock discrepancy. On an eMAR with PRN protocols attached to each medicine, the worker sees the protocol at the point of giving, the interval is enforced, the reason is recorded, and the outcome is prompted. That removes most of the paper problems and produces a PRN report per person that can be reviewed in minutes. Kiwi attaches the protocol to the medicine in exactly that way, and its 700-plus medicine dictionary means the interval and maximum are set once per prescription rather than retyped.

Reviewing PRN use: reading the pattern

Once a month, for each person, look at the PRN record. How many doses, of what, when, and for what reason? Is the pattern stable, rising or falling? Is there a time of day, a day of the week, a member of staff? Was the outcome recorded every time, and did the medicine work?

A rising pattern means something has changed: the person's health, their environment, their staff, or their regular medicines. A pattern tied to a shift or a worker means the protocol is being applied differently and training is needed. A pattern where the medicine never works means it is the wrong medicine or the wrong indication, and the prescriber needs to know. A falling pattern after a change to the care plan is the evidence that the change worked, and is worth writing down.

Take the record to the medicines review. A GP who sees three months of PRN use with reasons and outcomes can make a much better decision than one who is told he seems to need it a lot.

How to write a PRN protocol, step by step

1. Take the current prescription and copy the medicine, strength, form, route, dose range, interval and maximum exactly.
2. Write the indication in plain words that describe this person, drawing on the care plan and what the person and their family say.
3. List the signs that this person needs the medicine, including what to rule out first, and name any pain or distress tool to be used.
4. List the non-drug approaches to try first, in the order that works for this person, taken from the care plan or PBS plan.
5. Write the interval and the daily maximum in plain words, and say whether regular doses count toward it.
6. Say exactly what to record before, at and after the dose, and where.
7. Set the escalation thresholds: what to do if it does not work, and what level of use triggers a review.
8. Record the capacity position and any best interests decision, and what happens on refusal.
9. Have the prescriber or pharmacist check the clinical parts, and have the manager or nurse in charge sign and date it with a review date.
10. Put it where the worker will see it at the moment of decision, and train the team on it.

The PRN audit

Include PRN in the monthly medicines audit. For each PRN medicine on each chart, check the following.

• A protocol exists, is specific to this person and this medicine, and matches the current prescription.
• The protocol is signed, dated, and within its review date.
• Every dose given has a time, a quantity, a reason and a recorded outcome.
• No dose was given inside the minimum interval or above the daily maximum.
• Non-drug approaches were recorded before each dose where the protocol requires it.
• Any escalation threshold that was reached led to a review, and the review is recorded.
• Stock reconciles with the doses recorded.
• For sedatives used for distress, the PBS plan and the protocol agree, and ABC charts exist for each incident.

Record what you found and what you did. An audit and evidence system that keeps the protocol, the MAR, the PRN record and the audit together makes the story easy to tell on inspection day.

Training staff on PRN decisions

Medicines training covers administration. It rarely covers judgement, and PRN is judgement. Add a session, or a scenario in supervision, that takes a real protocol and works through a decision: here is what Tom is doing, what do you try, when do you give, what do you write. Include the escalation. Include refusal. Include the case where two workers disagree.

Competency assessment should include a PRN scenario, and the monthly audit will show you which workers' records are thin. The most common gap is the outcome: the dose is recorded and nobody goes back to check whether it worked. That is a habit, and it is fixed by asking for it every time.

Common mistakes

• No protocol at all. The medicine is on the chart with as required and nothing else.
• A generic protocol. The same paracetamol sheet for every resident, with no mention of how each person shows pain.
• Protocol does not match the prescription. The GP changed the maximum and the protocol still says the old one.
• No outcome recorded. Doses are given and nobody records whether they worked.
• Empty PRN boxes. Nobody can tell not needed from not recorded.
• Sedatives given at the first sign. The PBS plan says try five things first and the record shows none of them.
• No review threshold. Use creeps up over months and nobody notices until the inspector asks.
• Protocol in the office. The worker on the night shift has never seen it.

What good looks like on inspection day

The inspector picks a MAR chart and points at a PRN medicine. The senior on duty produces the protocol, which names the person, matches the prescription, describes how she shows pain, lists what to try first, states the interval and the maximum, and is signed and dated within the last six months. The inspector picks a dose given last week. The record shows the time, two tablets, the reason in the worker's words, the heat pad tried first, and a note an hour later that she was comfortable.

The inspector asks a worker how they decide. The worker explains the signs, the things to try, and the point at which they give the medicine, without looking at the sheet. The inspector asks about a resident whose PRN lorazepam is on the chart. The manager shows the PBS plan, the protocol that mirrors its reactive strategies, the two doses given in the last quarter with ABC charts for each, and the review with the prescriber that followed the second one. The PRN audit for last month is there, with one action, closed.

That is inspection-ready evidence for PRN. It is not that the medicine is never used. It is that every use can be explained.

Final conclusion

A PRN protocol is a small document that carries a large decision. It copies the prescription, describes the person, says what to try first, sets the limits, tells the worker what to record and when to ask for help, and is signed by someone who owns it. Write one for every PRN medicine for every person, keep it where the decision is made, audit the record against it every month, and use the pattern it reveals to improve the care. Done properly, it protects the person from too much medicine and too little, and it protects the worker who has to make the call.

Frequently asked

What is a PRN protocol?

A PRN protocol is a person-specific document for a medicine prescribed as required. It sets out the medicine and dose, what it is for, how the person shows they need it, what to try first, the minimum interval and daily maximum, what to record, when to escalate and who signed it off. NICE SC1 expects one for every when-required medicine in a care home.

Who should write a PRN protocol in a care home?

The clinical parts (medicine, dose, interval, maximum) come from the prescription and should be checked by the prescriber or pharmacist. The person-specific parts (signs, what to try first, what to record) are written by the home, usually the nurse in charge or keyworker, with the person or their family involved. The registered manager or nurse in charge signs and dates it.

Does every PRN medicine need a protocol?

Yes. Every medicine prescribed as required for every person should have its own protocol, including paracetamol and laxatives, not only sedatives. A generic protocol shared between residents does not meet the standard because it cannot describe how each person shows they need the medicine.

How should PRN medication be recorded on a MAR chart?

When given, record the time and the exact quantity in the box, with the reason and the outcome on the reverse or in the notes. When not given, use a code for not required or a line through the box so that nothing is blank. On an eMAR the protocol is attached to the medicine and the system records reason, interval and outcome.

How often should PRN protocols be reviewed?

Whenever the prescription changes, whenever the person's needs change, and at least at every care plan review. Many homes set a six-month review date. PRN use itself should be reviewed monthly in the medicines audit, and any escalation threshold in the protocol triggers a review with the prescriber.

What is the difference between a PRN medicine and a homely remedy?

A PRN medicine is prescribed for the person by a prescriber, with a dose, interval and maximum, and needs a protocol. A homely remedy is a non-prescribed medicine the home stocks for minor ailments under a policy agreed with the GP or pharmacist. If a person has a medicine prescribed as required, the homely remedy is not used for that indication.

Can PRN sedatives be given for challenging behaviour?

Only where prescribed for that purpose, under a protocol that mirrors the reactive strategies in the person's positive behaviour support plan, after the non-drug strategies have been tried and recorded, and with a capacity assessment and best interests decision where the person cannot consent. Every dose should have an ABC chart and a recorded outcome, and rising use should trigger a review.

Sources

• NICE guideline SC1 Managing medicines in care homes
• CQC: medicines guidance for adult social care, including when-required medicines
• Royal Pharmaceutical Society: The handling of medicines in social care
• GOV.UK: Mental Capacity Act 2005 Code of Practice
• NICE guideline NG11 Challenging behaviour and learning disabilities
• BILD: Positive behaviour support and the PBS Academy competence framework
• Skills for Care: medication competency and the Care Certificate