The Prescribing Safety Assessment is an open-book exam. You have the BNF, the BNF for Children and the interaction checker available throughout, and candidates hearing this for the first time tend to relax. They should not. Two hours for 60 items means the clock is the real examiner, and the single commonest way to fail this exam is not to be unable to find an answer. It is to find every answer, slowly, and run out of time. Reference access is not a safety net. It is a competency being tested.
Key takeaways
- You have full reference access, but only two hours for 60 items, so lookup time is the scarce resource.
- The exam tests your ability to navigate a reference efficiently, not just whether you eventually find the answer.
- Decide within seconds whether a question warrants a lookup or should be answered from recall.
- You still need a floor of recalled knowledge, because there is not enough time to look everything up.
- Treatment summaries are frequently the fastest route to an answer, and most candidates never use them.
The open-book paradox
Reference access removes the need to memorise doses. It does not remove the need to know medicine, and it introduces a new failure mode that closed-book exams do not have: the temptation to check.
Under pressure, checking feels responsible. You are fairly sure the dose is right, but you could confirm it. You are fairly sure that interaction matters, but you could look. Each check costs forty seconds. Do that on twenty items and you have spent thirteen minutes confirming things you already knew, and you will meet the last prescribing item, worth ten marks, with four minutes on the clock.
The discipline this exam actually demands is the confidence to answer from knowledge when you know, and the judgement to look only when looking changes something.
Triage every item in the first ten seconds
Before you do anything else with a question, decide which of three categories it falls into.
Answer from recall. You know this. First-line treatment for a common condition, an obvious interaction, a standard monitoring parameter. Answer it and move.
Look it up, deliberately and quickly. You have a specific, targeted question: what is the paediatric dose per kilogram, what is the dose adjustment in renal impairment, is this drug contraindicated in this situation. You know exactly what you are looking for, so the lookup is fast and it resolves the item.
Do not look it up at all. You do not know, and you also do not know what you are looking for, which means a lookup will become a fishing expedition. Make the best judgement you can, flag it, and move on. Time spent browsing without a target is time taken from items you could have scored.
The mistake is the middle category collapsing into the third: opening the reference without a precise question, and reading, hoping something will resolve your uncertainty. That is how ten minutes disappear.
Search by the right thing
Efficient navigation is a skill, and it is learnable in an afternoon.
Search by drug when your question is about a specific medicine: its dose, its cautions, its contraindications, its interactions. This is the fastest and most reliable route.
Search by indication when you know the condition and not the drug. This is where the treatment summaries earn their place, and they are the most underused feature in the whole reference. If you need first-line management for a condition you have not prescribed for since medical school, the treatment summary gives you the answer directly, structured for exactly this purpose, in far less time than assembling it from individual drug entries.
Use the interaction checker when the question is explicitly about interaction, particularly on prescription review items, where you are handed a list of medicines and asked which one is the problem. Even here, be targeted: you cannot check ten drugs against each other in the time available, so check the ones you suspect rather than all of them.
You still need a recall floor
Because there is not time to look up everything, some knowledge simply has to be in your head, and it is worth being explicit about what.
The common first-line agents for common conditions, so that you are not searching by indication for things you should simply know. The high-risk interactions that recur, because prescription review items are built on them. The standard monitoring parameters for the drugs that are always monitored. The drugs that are dangerous in renal impairment, in pregnancy, and in the elderly. The frank contraindications you should never need to check.
Build that floor deliberately during your preparation, and use spaced repetition for it, because these are precisely the facts that feel secure when you learn them and evaporate under exam pressure a month later.
Practise looking things up, at speed
This is the part almost nobody does, and it is the cheapest improvement available.
Do not simply practise questions. Practise the lookups, timed. Take a list of tasks, find the paediatric dose of this, find the renal adjustment for that, find whether these two interact, find the monitoring requirement for this drug, and do them against a clock until each one takes seconds rather than minutes.
The competency being examined is not whether you can eventually find the answer. Everyone can, given time. It is whether you can find it in the time you actually have, and that is a motor skill built by repetition, not a knowledge gap fixed by reading.
Protect the high-value items
One last point connecting this to the exam's structure. The prescribing items are worth ten marks each, five times the value of most other items. If your lookup discipline collapses and you run out of time, it is those items that suffer, and they are the ones you cannot afford to rush.
So manage the clock with the mark distribution in mind: answer or abandon the two-mark items briskly, and preserve time for the eight prescribing items that carry forty per cent of the paper.
Where iatroX fits
iatroX's PSA bank is tagged to the blueprint's item styles, so you can practise each competency separately and see which ones are actually costing you marks, and its explanations are grounded in current guidance including the SmPC, so the reasoning behind a dose, a contraindication or a monitoring requirement sits with the question rather than being left for you to reconstruct. That builds the recall floor that makes efficient navigation possible in the first place, and the adaptive engine returns the interactions and monitoring parameters you keep missing rather than letting them slide. Missed questions can be opened in the Socratic Tutor, which asks you to reason before it explains. Try it with free sample questions at iatroX. For why the mark weighting should reshape your whole approach, see the PSA's eight item styles.
Frequently asked questions
Is the PSA open book? Yes. You have access to the BNF, the BNF for Children and the interaction checker throughout. But with only two hours for 60 items, your ability to navigate them quickly is itself a competency being assessed.
Do I still need to memorise drug doses for the PSA? Not exhaustively, but you need a recall floor: common first-line agents, high-risk interactions, standard monitoring parameters, and the drugs that are dangerous in renal impairment, pregnancy and old age. There is not enough time to look everything up.
What is the fastest way to find information in the PSA? Search by drug when your question is about a specific medicine, and by indication, using the treatment summaries, when you know the condition but not the drug. Treatment summaries are the most underused shortcut in the exam.
How do I avoid running out of time in the PSA? Triage each item within seconds into answer-from-recall, targeted-lookup, or best-judgement-and-move-on. Never open the reference without a precise question, and protect time for the ten-mark prescribing items, which carry forty per cent of the paper.