A formulary is merely a list of medications that users agree to use or are encouraged to use preferentially. All doctors in the UK will be familiar with the BNF. Local formularies are distillations of the BNF to smaller, more manageable lists which limit choice but aim to increase cost-effectiveness and maintain good clinical governance. Prescribers become more familiar and expert with a limited range of drugs, and patients receive consistent prescribing, leading to greater patient safety and confidence.
Setting up a formulary
Prescribing plays a large part in the clinical care of patients in primary care and, on average, 10 items are prescribed for each patient annually.
There are large numbers of medications available to help manage most conditions.
A locally agreed formulary is likely to reflect local traditional prescribing patterns (if appropriate), and can be based on local clinical guidelines and primary care organisation (PCO) policies.
A practice formulary should aim to provide good cost-effectiveness, familiarity and expertise with a manageable number of medications, and reflect national and local policies and recommendations. The use of such a formulary should result in better clinical governance and more consistent prescribing.
First, discuss the issue with your partners and try to obtain universal agreement that a formulary is desirable and necessary. Enlist the help and support of other stakeholders, such as practice nurses, community nurses, local pharmacists and the PCO pharmaceutical adviser. However, be aware that the more people are involved, the harder it is to gain consensus, especially when some of those invited might have different agendas. In practice, start with the prescribing clinicians in the practice and only involve other parties once a provisional formulary is agreed.
Agree with your fellow prescribers a suitable timetable for drawing up the formulary and when to start using it.
Start by requesting a detailed report for the practice from PACT. These reports will include a record of every single prescription originating from the practice. From this report, the practice can see which preparations in each category of medications are being used most often. The layout of the report makes it relatively easy to see which preparations are being used for disease area and condition.
Use these commonly prescribed items as the basis for the formulary. Many categories will be populated by only one or two medications (for example, proton pump inhibitors), although some categories might offer a wider choice to reflect the subtle differences between preparations (for example, combined oral contraceptives).
Take into account any national, local hospital or PCO guidelines as well, but do not necessarily adopt them if the prescribers are not happy accepting these guidelines without alterations.
A provisional list can now be drawn up as the provisional practice formulary.
This needs discussion with the prescribers in the practice and the contents can be refined after discussion and consensus. In making decisions between different preparations in the same class, take into account what the practice has been using up to now, cost, quality (is there good evidence-based data to promote drug A over drug B?) and generic availability.
Many GPs will have their favourite drugs from which they are reluctant to switch, often despite good evidence. Selective indulgence might help acceptance of the practice formulary.
Once a formulary has been agreed, print a copy for all the relevant parties in the practice, including one for locum use. If possible, add the formulary to the practice computer so that the computer-generated picking-list for a particular drug will show the generic or brand name that the formulary recommends.
Maintaining the formulary
The formulary should be reviewed at least annually. Comparing what the practice has agreed to use in the formulary with what PACT tells the practice it has been using provides good comparative data. If a preparation not in the formulary is being used in favour of a preparation in the formulary, consider switching. Do not be fearful of adding drugs that are being commonly used and are not yet in the formulary, or of deleting from the formulary drugs that are seldom used. However, the formulary is designed to promote good, consistent prescribing, so a certain amount of professional discipline might be necessary.
- Dr Crockett is a GP and a hospital practitioner in respiratory medicine in Swindon, Wiltshire
Making a practice formulary work for GPs and patients
- Creating a formulary allows GPs to reflect on the safety, cost-effectiveness and logic of their prescribing habits. This can form part of a personal learning plan.
Agreement between GPs is not always possible. Flexibility might be needed and compromises made.
Ensure that GPs are in charge of the formulary and its implementation.
Initially involve GPs and other prescribers before taking expert advice from others such as PCO prescribing advisers.
Accept that only about 80 per cent concordance with the formulary is likely and every prescriber retains the right to maintain clinical freedom to prescribe.
Using the formulary should lead to more cost-effective and consistent prescribing.