The Hitchhiker’s Guide to Clinical Pharmacology Part 3: Choose wisely, inform, start low, and monitor Jeffrey K Aronson
In a podcast interview with Carl Heneghan on the subject of clinical pharmacology, I mentioned the British Pharmacological Society’s Ten Principles of Good Prescribing.
Prescribing medicines is the main approach to the treatment and prevention of disease and the alleviation of symptoms in modern healthcare. While medicines have the capacity to enhance health, all have the potential to cause harm if used inappropriately (see Box 1).
Box 1. Harms from medicines in the UK
Numbers of patients affected by adverse drug reactions
Reported rates of medication errors
For these reasons, the British Pharmacological Society recommends that healthcare professionals who prescribe medicines should do so based on ten principles that underpin the safe and effective use of medicines. They are summarized in Box 2, with notes below.
Box 2. Ten principles of good prescribing
All prescribers should:
In case this is too much to take in at one go, I recommend the following mantra, which summarizes the important points:
Choose wisely, inform, start low, and monitor.
Notes on the ten principles of good prescribing
- Be clear about the reasons for prescribing
- Establish an accurate diagnosis whenever possible (although this may often be difficult)
- Be clear in what way the patient is likely to gain from the prescribed medicines (benefits) and what harms may occur from treating or not treating (see item 5 below)
- Take into account the patient’s medication history before prescribing
- Obtain an accurate list of current and recent medications (including over-the-counter and alternative medicines) and undertake medication reconciliation
- Obtain a history of prior adverse drug reactions, interactions, and drug allergies and avoid drugs that may cause a recurrence
- This information may come from patients, carers, or other healthcare practitioners
- You can’t know about all interactions, so look them up, for example in the British National Formulary (BNF), which can be downloaded to your phone free if you work for the UK NHS
- Take into account other factors that might alter the benefits and harms of treatment
- Consider other individual factors that might influence the prescription (e.g. genetic factors, physiological changes with age and pregnancy, or impaired kidney, liver, or heart function)
- Take into account the patient’s ideas, concerns, and expectations
- Seek to form a partnership with the patient when selecting treatments, making sure that they understand and agree with the reasons for taking the medicine
- Select effective, safe, and cost-effective medicines individualized for the patient
- Be clear in what way the patient is likely to gain from the prescribed medicines (benefits)
- Be clear about the dual risks of the harms of treatment and the harms from not treating
- These two principles together form the benefit-harm balance (do the likely benefits outweigh the likely harms) and the risk-risk balance (do the likely harms of treating outweigh the likely harms of not treating)
- Whenever possible these judgments should be based on published evidence
- Prescribe licensed medicines for licensed indications
- Do not prescribe medicines “off-label” or outside standard practice unless satisfied that an alternative medicine would not meet the patient’s needs (this decision will be based on evidence and/or experience of the likely benefit-harm balance)
- Do not prescribe unlicensed medicines, except in unusual circumstances
- See Box 3 below for the differences between licensed medicines, unlicensed medicines, and off-label prescribing.
- Choose the best formulation, dose, frequency, route of administration, and duration of treatment
- In most cases, start with a low dose and increase gradually, monitoring the patient’s response
- Occasionally (e.g. glucocorticosteroids, warfarin, amiodarone) a loading dose may be needed
- Adhere to national guidelines and local formularies where appropriate
- Be aware of guidance produced by respected bodies (increasingly available via decision support systems), but always consider the individual needs of the patient
- Select medicines with regard to costs and needs of other patients (healthcare resources are finite)
- Be able to identify, access, and use reliable and validated sources of information (e.g. the British National Formularies), and evaluate potentially less reliable information critically
- Write unambiguous legal prescriptions using the correct documentation
- Be aware of common factors that cause medication errors and know how to avoid them
- Monitor the outcomes of treatment, both beneficial and adverse
- Identify how the beneficial and adverse effects of treatment can be assessed
- Understand how to alter the prescription as a result of this information
- Know how to report suspected adverse drug reactions (in the UK via the Yellow Card scheme)
- Communicate and document prescribing decisions and the reasons for them
- Communicate clearly with patients, their carers, and colleagues; this will encourage adherence to therapy
- Give patients important information about how to take the medicine, what benefits might arise, adverse reactions (especially those that will require urgent review), and any monitoring that is required
- Warn them about possible adverse drug interactions (e.g. statins with grapefruit juice)
- Use the health record and other means to document prescribing decisions accurately
- Prescribe within the limitations of your knowledge, skills, and experience
- Always seek to keep the knowledge and skills that are relevant to your practice up to date
- Be prepared to seek the advice and support of suitably qualified professional colleagues
- Make sure that, where appropriate, prescriptions are checked (e.g. calculations of intravenous doses)
Box 3. Licensed medicines, unlicensed medicines, and off-label prescribing in the UK
The UK regulatory authority grants product licenses (known formally as Marketing Authorisations), permitting license holders to market medicinal products for specified indications under specified conditions. Such products are licensed medicines.
Every license for a medicinal product contains information about the approved uses of the product; this information is known as the label and is given in the Summary of Product Characteristics (SmPC), whose contents are regulated by law. The information includes the pharmaceutical form, the therapeutic indications, doses, and mode of administration, contraindications, special warnings and precautions for use, adverse drug effects and reactions, and drug interactions.
If a licensed medicine is prescribed in a way that differs from the descriptions listed in the SmPC, that is off-label prescribing. For example, if bevacizumab, which is licensed for the management of various cancers, is used to treat age-related macular degeneration, that is off-label prescribing. This is not the same as prescribing an unlicensed medicine.
An unlicensed medicine is one that does not have a license in the UK.
MHRA advice on priorities when prescribing
(a) use a licensed product within the terms of its license (i.e. the label);
(b) use a licensed product off-label;
(c) use an imported product that has a license elsewhere;
(d) use a product that is not licensed anywhere, but which has been manufactured in the UK as a “special”.