From medical student to junior doctor:Clinical pharmacology to prescribing responsibility

In the fourth article in our series, Geoffrey Robinson, Sarah Aldington, and Richard Beasley give a practical guide to good prescribing practice

Prescribing drugs is an important part of most doctors’ work and begins suddenly on day one of the house officer year. Although pharmacology is a core component of the undergraduate curriculum, the processes of prescribing and its regulations and legal provisions are variably taught and supervised. Prescribing is one aspect of patient care where it is possible to do considerable harm.

Most junior doctors are unaware of the sizeable contribution prescribing aberrations make to hospital adverse reportable events and medicolegal activities. The incidence of drug related adverse events in patients in hospital varies widely—between 2% and 35%, depending on the rigour with which events are sought.^1-2 The leading cause of medical injury in hospital practice is adverse drug events, about half of which are the result of errors.²³ A study by a large insurer showed that injuries caused by drugs were the most common reason for procedure related malpractice claims.⁴

Although hospital pharmacists may do a chart audit, this should not be relied on—the prescriber has clinical and medicolegal responsibility. This article recommends simple assessment and prescribing guidelines.

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Prescribing safely, but writing legibly?

Documenting drug use on admission

Table 1 suggests a scheme that can be used by the admitting junior doctor to document drug use. Drugs can be tabulated in this way in the patient’s notes. It is always worth asking about compliance and drug allergies, and do not forget to read Medic Alert bracelets, especially in unconscious patients. Ask about recent changes in drug dosage, which may have precipitated the presenting illness. And ask about over the counter drugs and homeopathic treatments.

With the large number of drugs available, it is impossible for any doctor to obtain and retain the necessary knowledge to use all drugs optimally. When a patient is taking a drug with which you are unfamiliar, look it up. Consider the possibility that the admission is the result of a drug related adverse event, which may be responsible for up to one in eight of all admissions to medical wards.^5-6

Prescribing in hospital

Junior doctors need to develop a critical approach to prescribing. Most prescribing mistakes are made because of a lapse in attention or because the prescriber did not apply the relevant rules. Junior doctors have identified many risk factors for prescribing errors, including heavy workload, whether or not they were prescribing for their own patient, communication within the team, physical and mental wellbeing, and lack of knowledge.⁷

The box represents the gold standard for prescribing in hospital. The risk to benefit ratio should be considered for each prescribed drug, with this appraisal undertaken regularly. The responsible prescriber weighs up the following: severity of illness, the drug’s efficacy, risks and severity of adverse effects, and drug interactions (especially in elderly patients with polypharmacy). The British National Formulary is the core reference, not drug company promotional material.⁸

A small number of common drugs account for a sizeable proportion of morbidity in hospitals, as recently identified by the District Health Board of New Zealand. These “dangerous five” require particular attention (table 2).

Adverse drug reactions often go unreported. It is good practice to report all serious reactions, as well as other suspected side effects, to the Committee on Safety of Medicines. This is done by completing one of the yellow cards in the back of the British National Formulary.

Junior doctors should minimise risks to nursing colleagues and patients by clear charting and instructions. Poor charting is increasingly reported on hospital incident forms as nurses become more aware of this problem. When in doubt, always look up drug dosages, side effects, and interactions. Taking the time to chart clearly will save time in the long run (for example, questions from nurses or defending yourself in front of a disciplinary committee). Mistakes made during prescription represent the most common type of avoidable drug treatment error.^9-10

Therapeutic drug monitoring is an important part of the junior doctor’s job and contributes to improved prescribing. This particularly applies to drugs with a low therapeutic index and includes digoxin, aminoglycosides, anticonvulsants, lithium, methadone, and theophylline.
 

Discharge process and prescription

The responsibility for prescribing lies with the doctor who signs the prescription. Liaison with nurses and hospital pharmacists is required to develop this important part of the discharge plan. Most patients benefit from a copy and explanation of the discharge prescription. Compliance and safety systems such as unit dose boxes and blister packs for dispensing drugs need to be considered. While blister packs, such as those used for the oral contraceptive pill, are useful for single dose once a day treatment, many patients take a number of drugs several times a day. Unit dose boxes with both the day of the week and the dosage time labelled are helpful in improving compliance and avoiding dosing errors. Patients should be warned about the dangers of driving when opioids or sedatives are newly prescribed.

General practitioners should be given guidelines about the use of uncommon drugs. Advice on monitoring for adverse effects may be required for drugs such as amiodarone and sodium valproate, particularly if specialist follow-up is not envisaged. Special arrangements should be made for patients discharged on warfarin in whom the maintenance dose has not yet been established.

The discharge prescription is fraught with hazards, particularly when drugs taken on admission are returned to the patient sometimes at different dosages. Be clear on the duration of discharge prescriptions, and advise the general practitioner accordingly.

Controlled drugs

Controlled drugs (of potential abuse) need special consideration. In the emergency department in particular, junior doctors meet drug dependent patients and “drug seekers,” who are skilled at getting their needs met. You may be faced with a situation in which you are uncertain whether you are supplying drugs to an addict or denying them to someone who genuinely needs them. The hallmarks of drug seekers include:

• Nominating drugs of abuse
• Reporting lost or stolen prescriptions
• Letters from hospitals or doctors not easily confirmed
• Difficult to substantiate clinical scenarios (pain syndromes, social stresses).

Forgery can be reduced by faxing or posting prescriptions for controlled drugs and benzodiazepines rather than giving them to patients directly.

Summary

Prescribing is an onerous responsibility, where primum non nocere (first do no harm) is an important rule. These guidelines incorporate practical recommendations to improve safety and support best prescribing practice by house officers.
 

Geoffrey Robinson, general physician and chief medical officer
Email: Richard.Beasley@mrinz.ac.nz
Sarah Aldington, senior research fellow
Richard Beasley, general physician and professor of medicine, Medical Research Institute of New Zealand and Wellington and Kenepuru Hospitals, Wellington, New Zealand


studentBMJ 2006;14:1-44 January ISSN 0966-6494

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8. BMA and Royal Pharmaceutical Society of Great Britain. British National Formulary. London: BMA and RPSGB, 2002: 818.
9. Leape LL, Bates DW, Cullen DJ, Cooper J, Demonaco HJ, Gallivan T, et al. Systems analysis of adverse drug events. JAMA 1995; 274: 35-43.
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