Five common prescribing errors – and how the PSA can help

Medico-legal advisers Rachel Stewart and Jenna Fowler offer advice on minimising risk with prescribing errors and preparing for the Prescribing Safety Assessment.

Whether it's providing analgesia for a patient with pain, or antibiotics to treat a pneumonia, it's likely that within your first days as a doctor you will be asked to prescribe, and it's also a common on-call bleep. It's a privilege to be able to prescribe, so it's important to treat this with appropriate responsibility as failing to do so can result in errors.

The Prescribing Safety Assessment (PSA) is a computer-based test aimed at assessing the outcomes related to safe prescribing that the GMC expects all medical graduates to possess. It comprises eight sections covering common issues you could face as an FY1, including prescription reviews, drug monitoring, and adverse drug reactions. It also allows students to become familiar with using the British National Formulary (BNF), a key resource for information on the selection, prescribing, dispensing and administration of medicines.

Here, we discuss the five common prescribing errors that we see, steps you can take to reduce the risk of them happening, and how the PSA can help in putting this into practice.

Five common prescribing errors

Failing to consider drug interactions and contraindications

The GMC says that doctors should only prescribe a medicine if they have adequate knowledge of a patient's health. This is important because you can't check for any contraindications, cautions or drug interactions unless you have the full picture of a patient's medical and drug history. Examples of errors include prescribing NSAIDs for a patient with renal impairment, or prescribing an antibiotic that interacts with a patient's warfarin.

To minimise this risk, always check a patient's history before you prescribe. It can be helpful not only to check the patient's records but also to speak to the patient in case they are taking something that isn't documented (for example, an over-the-counter or herbal medicine).

Prescribing the wrong dose

There can be multiple factors to consider when deciding which dose of a medicine to prescribe, such as the drug's indication, the patient's renal and/or liver function, or the weight and age of a patient, particularly when prescribing for children. Errors can also happen if the incorrect measurement is used - for example, micrograms instead of milligrams.

When preparing for the PSA, take time to become familiar with the sections of the BNF that apply to medicine dosages. Be sure to refer to these when you start working to minimise the risk of errors.

Failing to monitor appropriately

There are several types of drug monitoring that might be required. For example, checking the levels of a drug, to look for side effects like renal impairment, or to monitor a drug's effectiveness such as checking lipid levels in patients taking statins.

GMC guidance states that, when prescribing, you must make sure that suitable arrangements are in place for monitoring, follow-up and review. It is the prescribing doctor's responsibility to make sure arrangements are in place, so it's important to note any required monitoring, document this in the patient's records and hand this over to colleagues where appropriate, including the patient's GP.

The PSA section on drug monitoring may be helpful in familiarising yourself with common monitoring requirements, as well as ensuring you know how to find these in the BNF.

Electronic errors

The introduction of computer-based prescribing systems means no more struggling to decipher what medications patients are on, or re-writing drug charts for long-stay patients. However, new systems create the potential for new errors. Often, they allow you to begin typing the medicine's name, and then select your desired preparation from a suggested list. This can lead to either the incorrect strength being prescribed (particularly for branded products like inhalers), or even an incorrect drug with a similar sounding name (such as Amiodarone instead of Amlodipine).

Although it sounds simple, be sure to double check any prescription before confirming, and avoid the temptation to try to multi-task when on a busy shift.

Prescribing to someone with an allergy

It's crucial to check a patient's allergy status before prescribing, and the GMC makes clear that if you need more information to decide what options would serve a patient's needs, you should ask for it before proceeding with the course of treatment.

As well as speaking with the patient, you should check the records for any reported allergies and to see whether the patient has had the drug previously. You should also make a note in the records that you have asked the patient about their allergies. There will be questions in the PSA that ask you to choose the most suitable medication for an individual patient, so you can get used to taking this into consideration.

Familiarise yourself with GMC guidance

Prescribing is a core task and learning about this for the PSA is an important step in preparing for work as a doctor. Improving your knowledge of prescribing has multiple benefits, including reducing the risk of errors and complaints, improving patient safety and increasing your confidence as a doctor. Read our guide to prescribing duties here.

Remember to become familiar with the GMC's guidance on prescribing and refer back to it when needed. It takes time and experience to become comfortable with prescribing, so don't be afraid to take the time you need to do this and carefully check the patient's records and the BNF. Get support whenever you're not sure.

While the PSA will help you to be ready for your first days of prescribing, as you develop as a doctor and take on increased responsibility, your scope of prescribing may expand. It's important to be aware that prescribing errors can still happen even when you're more experienced.

Keep this in mind, make sure you keep up to date with recent developments, and never hesitate to seek advice from a colleague or the ward/practice pharmacist if you're unsure about something.

This page was correct at publication on 14/09/2023. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.

Dr Rachel Stewart

by Dr Rachel Stewart

Rachel is a medico-legal fellow at the MDU, having previously worked as a clinical fellow in plastic, reconstructive and burns surgery. She graduated in 2019 from the University of Edinburgh, and it was during this time that her interest in law and medical ethics began, working as a committee member of the Medical Ethics and Humanities Society. She also enjoys teaching and mentoring, and is currently doing a part-time Master of Education degree in Surgical Education at Imperial College London.

Dr Jenna Fowler

by Dr Jenna Fowler MDU medico-legal adviser

Jenna studied medicine at the University of Edinburgh and graduated with honours in 2016. She then went on to train as a GP and worked as a GP in Scotland until April 2023. Jenna joined the MDU initially as a medico-legal fellow in 2022 and became a medico-legal adviser in May 2023.