The below article has been reproduced from a BMJ series to help medical students make the leap to budding doctors. In this article, Geoffrey Robinson and authors 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.^2,3 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.

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

Table 1. Scheme for recording drug history on admission
Drug	Diclofenac
Dose	75 mg slow release
Frequency	Twice a day
Duration	Many years
Indication	Rheumatoid arthritis
Side-effects	Major gastrointestinal bleed two years ago

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

‘Guidelines for prescribing in hospital’ below 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 (please note: in New Zealand this is the New Zealand 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. These “dangerous five” require particular attention (table 2).

Guidelines for prescribing in hospital

Use block letters Use generic names Chart at routine times where possible—that is, chart drugs for the times listed on the drug chart which normally coincide with the nurses’ drug rounds Unclear decimal points are dangerous (precede by zero where applicable) Write out micrograms in full Specify slow release preparations As required medication (pro re nata—when circumstances dictate)—notate indication, frequency, and maximum dose/24 hours Identify yourself as the prescriber Review charting in liver and in renal disease Review chart daily Chart oxygen flow rate and delivery system

 

Table 2. “Dangerous five” drugs in hospital practice
Drug	Comments
Heparin	Be clear on prophylactic versus treatment dose Low molecular weight heparin preferable to unfractionated heparin Dosage adjustment in renal impairment
Warfarin	Consider contraindications and risks associated with use† Stop aspirin and avoid non-steroidal non-steroidal anti- inflammatory drugs Watch for interactions, for example, antibiotics Determine the therapeutic international normalised ratio target for different conditions Give patient information
Morphine	Care in respiratory patients Different formulations and brands Cause of confusion in the elderly
Insulin	Is the patient eating? Monitor blood glucose regularly, including at night
Potassium supplements	Care in renal impairment supplements Potassium sparing diuretics and angiotensin converting enzyme inhibitors
Bedside questions to assess risk: alcohol, falls, dementia, hypertension, recent gastrointestinal bleed.

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 (please note: in New Zealand this is MedSafe).

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 applies particularly to drugs with a low therapeutic index and includes digoxin, aminoglycosides, anticonvulsants, lithium, methadone, and theophylline.

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. 

Discharge process and prescription

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.
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.

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.

 

Original authors:
Geoffrey Robinson, General physician and chief medical officer
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.

We gratefully acknowledge the BMJ for permission to reproduce this article.

References

1. Karch FE, Lasagna L. Adverse drug reactions: a critical review. JAMA 1975;234:1236-41.
2. Brennan TA, Leape LL, Laird NM, Hebert L, Localio AR, Lawthers AG, et al. Incidence of adverse events and negligence in hospitalized patients: results of the Harvard Medical Practice Study I. N Engl J Med 1991;324:370-6.
3. Leape LL, Brennan TA, Laird N, Lawthers AG, Localio AR, Barnes BA, et al. The nature of adverse events in hospitalized patients: results of the Harvard Medical Practice Study II.  N Engl J Med  1991;324:377- 84.
4. National Association of Insurance Commissioners. Medical malpractice closed claims, 1975-78. http://www.naic.org
5. Roughead E, Gilbert A, Primrose J, Sansom L. Drug-related hospital admissions: a review of Australian studies published 1988-96. Med J Aust 1998; 168:405-8.
6. Peyriere H, Cassan S, Floutard E, Riviere S, Blayac JP, Hillaire-Buys D, et al. Adverse drug events associated with hospital admission. Ann Pharmacother2003;37:5-11.
7. Dean B, Schachter M, Vincent C, Barber N. Causes of prescribing errors in hospital inpatients: a prospective study. Lancet 2002;359:1373-8.
8. BMA and Royal Pharmaceutical Society of Great Britain. British National Formulary. London: BMA and RPSGB, 2002:818.1995; 274: 35-43.
9. Leape LL, Bates DW, Cullen DJ, Cooper J, Demonaco HJ, Gallivan T, et al. Systems analysis of adverse drug events. JAMA
10. Bates DW, Cullen DJ, Laird N, Petersen LA, Small SD, Servi D. Incidence of adverse drug events and potential adverse drug events: implications for prevention. JAMA 1995;274:29-34.

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