The Wrong Prescription

Problems can occur throughout the entire medication process – from prescribing, dispensing, administration, to monitoring of effects.

The role of the clinical pharmacist

As a clinical pharmacist it is my responsibility to ensure “the safe and effective use of medicines.” The role of the pharmacist has evolved greatly over the past few decades, so that the traditional view of the pharmacist in the dispensary checking dispensed prescriptions no longer holds true for the profession as a whole. The clinical pharmacist is usually found at the patient bedside or in the GP surgery and is involved in all aspects of the medication process, from advising doctors on appropriate drug therapy, to ensuring systems are in place to promote safe prescribing and administration of medication, to educating patients, carers, medical and nursing staff about drug therapy.

Experts on all aspects of drug therapy

The clinical pharmacist is an expert on drug therapy and should be aware of all the potential dangers inherent in the medication process, as well as making sure the patient is receiving the most appropriate drug in the right dose and frequency for their condition Clinical pharmacists draw up protocols and guidelines for the use of many drugs and are in effect guardians of medication safety.

Recognising and minimising the risk

Because of this role it means putting systems in place to minimise medication errors and this involves an understanding of what can go wrong and a depth of experience of what has gone wrong in the past. Most healthcare professionals are unaware when they have made medication errors and the clinical pharmacist can and does identify these and provides education and improves systems to make sure they don’t happen again. It is this experience that can prove invaluable as an expert witness in medicines, drugs and therapeutics, the ability to recognise that something has gone wrong, and how that has come about.

Prescribing

Prescribing medication is the most common medical intervention that doctors will make in their careers. However, like many aspects of medical training, learning about prescribing is experiential and formal training is patchy in medical schools. When I started education in prescribing skills for fifth year medical students more than ten years ago at the University of Manchester, the students would usually ask why they had never had this kind of training before. Many qualified doctors to this day don’t have formal training in prescribing skills. This means that doctors pick it up as they go along and end up learning from their mistakes which can pose problems for example in the hospital environment where the least experienced doctors do the vast majority of the prescribing. Two studies of prescribing errors the EQUIP and PROTECT studies showed approximately 2/3 of all hospital prescriptions are written by year 1 and year 2 doctors, with an error rate of between 7.5 to 10%. This compares to consultant error rates of around 6%. The PRACTiCE study in general practice also highlighted at least one error occurring in every 20 prescriptions

Although these rates seem scarily high, the vast majority of these errors are very minor or never get to the patient through intervention from other health care professionals such as nurses, pharmacists and other doctors so that they have no potential for harm.

The other side of that coin is the number of errors that do significantly impact on the patient causing temporary or permanent harm, or are even fatal. 20% of all clinical negligence claims against doctors are for medication errors at an estimated cost of £1 billion per year in additional health expenditure, not to mention litigation costs. Annually there are over a billion prescriptions issued in primary care alone.

Medicine has evolved from the days of the generalist who had a wide experience if not specialist knowledge of patient conditions as a whole, to the superspecialists of today who focus on one organ or even specific parts of one organ. In cardiology for example there are specialists in abnormal heart rhythms, heart failure specialists, interventional cardiologists who clear out blocked coronary arteries and so on. This super-specialism means they become more and more focussed on one particular aspect or location of disease which can lead to deskilling from other fields.

Its not just doctors who prescibe these days. Other health care professionals such as nurses and pharmacists are increasingly taking on the role of prescriber after additional training has been undertaken.

Common culprits

The most common drugs that can result in harm are antidiabetic drugs including insulin, anticoagulants (blood thinning drugs), painkillers including opiate type drugs, chemotherapy and antibiotics.

Insulin is probably the number one drug in terms of causing serious harm to patients. If the dose is too large, or there is a break in the food intake of patients with no monitoring, serious episodes of low blood sugar which can lead to severe brain damage or death can and do occur with depressing regularity

Inappropriate use of these other drugs can result in serious harm and death and there are many examples of these recurring over the years. Inappropriate administration of vincristine (a chemotherapy drug) injected into the spine causing death happened a shocking 18 times before a concerted effort to prevent this happening again was undertaken. There are many other examples. Methotrexate is a drug used for some inflammatory conditions but is usually only given once a week. Lack of understanding of this when patients are admitted to hospital has led to patients being prescribed and administered this powerful immunosuppressant every day, leading to bone marrow damage and overwhelming infection and death. This has happened on multiple occasions.

Many other drugs have the potential to cause harm if they are prescribed for the wrong patient, in the wrong dose, wrong frequency or by the wrong route.

What can go wrong?

There are a large number of variables to take into account before prescribing a drug in a process that is usually undertaken in an instant.

• Is it for the right patient?

Making sure you have the right patient sounds basic but mistakes happen frequently

• Is it the right drug?

Misprescribing the wrong drug can happen for many reasons. The days of handwritten prescriptions are for the most part behind us in the community, but electronic systems bring their own hazards. Misselection of drugs from drop down menus are a frequent source of error.

Similarly the universal use of smartphone apps can and have lead to mistakes in choice of drug prescribed. Dr Google doesn’t actually have a medical degree.

Omission of drugs for a particular condition too are common errors. I have come across many cases where patients have developed an abnormal rhythm of the heart, atrial fibrillation, and should have been prescribed anticoagulants (blood thinning drugs) to prevent blood clots forming in the heart but this has been overlooked and has lead to strokes. I have been involved in numerous claims where this has been a problem, or where for some reason there have been delays or omissions in prescription or supply.

Similarly, failure to regonise how sick patients can be led to serious and sometimes fatal consequences. Patients with infections can become very ill very quickly if they are not prescribed the correct antibiotics in a timely manner. Recognising the septic atient means that antibiotics should be given within an hour of diagnosis - there are many examples where this has not happened with devastating consequences.

• Do I know about this drug before prescribing it?

It should be a fundamental principle that any doctor prescribing a drug should have some knowledge about what they are prescribing, but this is sometimes not the case and can happen when doctors are busy, or continuing the prescriptions that other doctors have initiated. In particular, prescribing on someone else’s advice such as a specialist can bring it’s own dangers. There have been cases where a typo adding an extra zero to the dose of a drug from a letter to the GP leading to a tenfold overdose has resulted in serious harm to a claimant. There is no defence that “a big boy done it and ran away” Responsibility for the prescription remains with whoever prescribes it.

• Is it the right drug for the patient?

Another common factor when things go wrong is that the prescriber doesn’t know enough about the patient. They don’t have enough knowledge of the history of the patient to be able to make an informed choice about the drugs they are prescribing. This happens all too commonly when things go wrong.

• Do they have allergies, intolerances?

It never fails to surprise me the number of times that no heed is taken of the patient’s clearly documented allergies or previous intolerances to drugs. Perhaps it’s the pharmacist in me but the very first thing I do when scrutinising prescriptions is to check this first as a matter of course.

Another pitfall in the allergy/intolerance conundrum is to go the other way entirely. I have seen examples where patients who have stated they are allergic to penicillin are given an inadequate substitute and develop a serious life threatening infection or who have even died of septic shock. Overstating minor intolerances can lead to potentially life saving or disease modifying treatments being withheld inappropriately.

• What about other conditions they have - will it affect them in any way?

Certain drugs can have adverse consequences in some disease states and these need to be taken into account. Some anti-inflammatories and antihypertensive drugs can cause worsening of kidney function in predisposed individuals, for example and again is a common cause of prescribing error

•Do they have kidney or liver damage that would affect the way the body handles the drug?

Poorly functioning kidneys and/or liver can mean that there is an accumulation of the drug in the body leading to toxicity. Some opiates can do this, for example morphine can accumulate in kidney failure leading to depressed breathing and respiratory arrest. Not taking kidney function into account is a very common cause of error and I have seen dozens of examples of this.

• Are they elderly? Are they a child?

Older patients and children handle drugs very differently from adults and drug dosages tend to be very individualised for children depending on their body weight. It is not uncommon to make mistakes in calculations for children that can lead to a tenfold overdose.

It may be the case that a patient has been taking a drug for many years but as they get older the effects of the drugs become more potent with accompanying side effects and this has not been recognised leading to successful claims.

• What other drugs are they taking? Is there a potential for serious interaction?

There are certain drugs that can have their effects boosted and therefore more potent when new drugs are prescribed. A common example is the antibiotic clarithromycin which many patients are prescribed for short courses for chest infections. I have seen dozens of cases where this has caused problems with long term medications such as transplant medications or antipsychotic drugs, among others. It is impossible to keep track of all the interactions that drugs can have with each other as dozens of new drugs are released onto the market every year. There may be a reliance on software to flag these up when they are being prescribed on electronic systems but the number of alerts that are generated for trivial reasons means that the user very quickly develops alert fatigue having to click through all of the warning screens that it is all too easy to miss the ones that matter. Again I have come across many examples of this leading to harm, both in doctors and pharmacists electronic systems

• What are the side effects and have I warned the patient about these?

Recognition that a drug is causing a side effect comes back to knowing about the drug that is being prescribed. It is the responsibility of the prescriber to know about the drug they are prescribing. There are multiple cases where claimants have made repeated visits to the GP and it has not been recognised that the symptoms are in fact due to side effects of the drug they have been taking, even when these side effects should be common knowledge to the prescriber. Angioedema (swelling under the skin and soft tissue) is a rare but well known side effect of an antihypertensive group of drugs called the ACE inhibitors. The claimant had been seeing his GP over a period of months with these symptoms, but it was only on an incidental visit to hospital that a relatively junior doctor recognised the symptoms and made the correct diagnosis. After stopping the ACE inhibitor the symptoms disappeared and a successful claim was made.

• How do I know if the patient is developing toxicity? How do I know if it’s working?

Monitoring the effects of prescribed drugs is an essential part of the prescribing process but it is often surprisingly overlooked. Once the drug has been prescribed it is sometimes seen that this is the end of it, but the prescriber needs to know if the patient is experiencing toxic effects of the drug or that the drug is having the desired effect. If it is not having the desired effect then the particular disease being treated can progress with serious consequences. Monitoring the effects of cholesterol lowering drugs such as the statins, for example, is vital to ensure that patients are not at risk of worsening cardiovascular disease such as heart attacks or strokes

• Does the patient have enough information about the drug for them to take it safely?

Patients need to be involved in their treatments. They need to know the best way to take it, what to look out for in terms of side effects and so on. It might be the case that one drug that the patient has been taking has proved ineffective so the intention is to replace that with a more potent drug that does the same thing. An example I have come across is a patient taking a statin drug to lower cholesterol. When the cholesterol wasn’t lowered enough a new drug was prescribed. The specialist, the GP and the pharmacist never made sure that the patient was aware that they were to stop taking the initial drug and the patient went on to develop life threatening toxicity as a result.

All of these things need to be processed in an instant when the prescriber is choosing a drug for a particular patient. Mercifully, significant mistakes are relatively rare.

Dispensing errors

When the prescription is dispensed this can lead to problems also. By far the most common error in the pharmacy is the selection of the wrong drug. There are numerous examples of this eg a claimant was given a diabetic drug instead of her usual beta blocker. A double whammy as the claimant collapsed with low blood glucose and developed a fast heart rhythm because she didn’t get her usual beta blocker.

Pharmacists have a duty of care to their patients just as any other healthcare professional. Many pharmacists and doctors don’t appreciate this. They need to make sure that any mistake or oversight made by prescribers does not get through to their patients , even if the prescriber insists that was what they intended and allowing the prescription to go ahead

Checking interactions is also a basic part of the pharmacist’s role, but again electronic systems if relied upon tend to lead to alert fatigue and the important ones can be missed. Most interactions are minor however there are a number of serious interactions that can have devastating consequences for patients.

Counselling patients on the proper use of their medication is an integral part of the pharmacist’s duty to make sure that the patient is involved in the decision to engage in their treatment and to understand the risks and side effects of their treatments.

Adminstration errors

Medication administration errors are defined as difference between what the patient received or was supposed to receive and what was intended. These types of medication error can be made by nursing staff and doctors directly administering drugs to patients.

Mis-selection of drugs is probably the most common type of error. A nurse being interrupted on a medicine round causing distraction can lead to the wrong medication being administered, or an anaesthetist taking a vial of what they believed was an antibiotic only to find that on administration to the patient that it was a general anaesthetic or a paralysing agent which unfortunately happens all too often even now.

Checking and double checking intravenous drugs is the source of potentially most harm. Because intravenous drugs are injected directly into the bloodstream they have immediate and potent effects, and mistakes in selection of drug , how it is prepared or how fast it is given can have disastrous consequences for the patient.

In the busy ward environment there is plenty of opportunity to take short cuts in the checking procedure and to accept that what someone is telling you is actually the case rather than checking independently. This is known as automaticity, the checker believes that they are checking a syringe of potassium when in fact it’s a syringe of morphine leading to respiratory arrest.

Mistaking one prepared syringe for another, or the use of unlabelled open systems with clear fluids in the operating theatre is a real and all too common problem.

Making up the drugs in the wrong way can also lead to serious harm. Injecting concentrated solutions that are supposed to be diluted can cause serious tissue damage or organ toxicity.

There are multiple other things that can and do go wrong, and it is vital that practitioners are provided with the right training,environment and support to mitigate the risk.

Summary

Medication errors are a significant problem in medical injury and clinical negligence cases. The clinical pharmacist has a vital role in minimising the occurrence of these problems, but when they do happen being able to recognise them in the first place.

The medication process involves many complex steps and there is opportunity for error along the way. The examples highlighted here are just a snapshot of the wide range of things that can go wrong.

Anthony Mark Dunne

BSc (Pharm), SuppPresc Cert.,

Dip Clin Pharm, MEd. MRPharms

Highly Specialist Clinical Pharmacist Critical Care and Medicines, Drugs and Therapeutics Expert.

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