Introduction

When prescribing, there are a number of points to take into account. Many doctors do this automatically but this record will provide you with some pointers and reminders to bear in mind when prescribing.

Primum non nocere

Hippocrates' advice still holds today. Prescribe only where necessary, and consider benefits versus risks. Involve the patient in decisions about their care and respect patient autonomy.

Note the patient's age, medical history (especially of any hepatic or renal dysfunction) and any concurrent medication. Think about dosage carefully; manufacturers' recommended doses are based on population studies and assume 'one dose fits all'. However, there are genetic differences.^[1] New drugs are often marketed at the highest therapeutic level to demonstrate effectiveness in large numbers of patients but companies are not required to provide data on lowest effective dose.

If this is a new - potentially long-term - prescription, review the patient to assess for effect, side-effects and the need to continue.

Prescribing guidance^[3]

Writing prescriptions

Many prescriptions are now computer-produced but, if you are hand-writing one, write legibly in indelible ink, date the prescription and state the full name and address of the patient. All prescriptions should be signed by the prescriber. It is a legal requirement in the case of prescription-only medicines to state the age for children under 12 years, but it's good practice to do so in all cases. Other things to take care of include:

• Write generics unless there are bioavailability issues, as this will enable the pharmacist to dispense any suitable preparation, avoiding expense and delay.
• Avoid unnecessary use of decimal points (eg 3 mg, not 3.0 mg). For quantities less than 1 gram, write in milligrams (eg 500 mg, not 0.5 g). For quantities less than 1 milligram, write in micrograms (eg 100 micrograms, not 0.1 mg). Don't abbreviate micrograms, nanograms or units. Use millilitres (ml or mL) not cubic centimeters or c.c.
• Schedules should preferably be written in English, without abbreviation but some Latin abbreviations are acceptable (such as qds, tds, bd, od, and so on). For prn dosage, state minimum dose interval and maximum total amount.
• The 'number of days of treatment' box can be used on NHS forms.
• Specify the strength and quantity. In the absence of this information the pharmacist will attempt to contact you. If unable to do so, they can use their discretion and professional judgement to dispense up to five days' worth of treatment or appropriate amounts of combination packs or oral contraceptives. If they have insufficient information to make a judgement, they will return the prescription to you.
• If you want anything other than the name, strength, and dosage of the tablets to appear on the label, write it on the prescription in inverted commas - eg 'Sedative Tablets'.
• Avoid abbreviations of drug names and preparations as these can be misinterpreted - eg Mist.Expect. Don't invent compound generic names, especially for sustained-release preparations.

Computer-issued prescriptions

The recommendations of the Joint GP Information Technology Committee of the British Medical Association (BMA) are:

• Minimum data requirements are:
  Date
  Patient's surname, one forename, other initials
  Address, title
  Date of birth
  The age of children under 12 years and of adults over 60 years must be printed in the box available; the age of children under 5 years should be printed in years and months.
• Doctor's name must be printed at the bottom of the prescription form, surgery address, telephone number, reference number and primary care organisation. Prescriptions issued by GP registrars, assistants, locums, or deputising doctors should bear the name of responsible principal.
• The prescription must be printed in English without abbreviation, the dose must be in numbers, the frequency in words, and the quantity in numbers in brackets (eg 40 mg four times daily ).
• Supplementary warnings or advice should be written in full.
• Handwritten alterations should only be made in exceptional circumstances and any alterations must be countersigned in the doctor's own handwriting.
• Clearly mark duplicates as such.

Repeat prescriptions

It is not unusual for other members of staff to write or for computers to generate repeat prescriptions for you to sign. This can be an efficient time-saving measure but you must ensure that:

• You have the correct prescription for the correct patient
• The patient is being regularly reviewed both in terms of side-effects and with regards to the ongoing need for this medication
• The correct dose is issued if there are changing doses over time

You are ultimately responsible for these prescriptions.

Hospital prescriptions

There can potentially be some confusion around ongoing prescriptions of a drug for a condition that is being managed by a hospital team. Ultimately, the responsibility is shared and you have a duty to keep yourself informed about the nature of the drugs that have been prescribed and about their side-effects. The General Medical Council (GMC) states that 'there should be full consultation and agreement between general practitioners and hospital doctors about the indications and need for particular therapies' although, in practice, this may be difficult when you may only hear about the hospital visit days or weeks after the event. If you are unsure about the management plan or any of the specific treatment modalities, clarify this with the hospital team.

Remote prescribing

Occasionally, you may find yourself needing to issue a prescription without face-to-face contact with the patient. If you have responsibility of care for the patient (or are deputising for a doctor who has), you have prior knowledge about the patient's medical background (or have authorised access to their notes), then you may consider remote prescribing (telephone, fax, email, video link or via a website). In these cases, you must:

• Establish what all the current medical conditions are, current drug history and any over-the-counter drugs.
• Carry out an adequate assessment and identify likely cause of the condition.
• Ensure that there is enough justification to prescribe and rule out any contra-indications.

If you are not the patient's usual doctor or deputising for the patient's doctor and if you do not have authorised access to their notes, you can still prescribe remotely if:

• You fully explain the process to the patient, give them your name and GMC number.
• Go through the steps above to ensure safe prescribing.
• Ensure appropriate follow-up ± monitoring of drug effects and side-effects.
• Inform the patient's general practitioner. If the patient objects to this, you have the responsibility for providing all necessary aftercare for the patient until another doctor agrees to take over.

Patients abroad

The issues are broadly similar to those where remote prescribing takes place in the UK. However, don't forget:^[3]

• Products may have a different licensed name, indications and recommended dosage regimen.
• You may need to be registered with a local regulatory body in the country in which the prescribed medicines are to be dispensed.
• You should ensure that you have adequate indemnity cover for prescribing for somebody abroad.

Prescribing controlled drugs

See separate article Controlled Drugs for more details.

Prescribing unlicensed medicines or off-label^[4]

Even though a medicine is unlicensed and is lacking a body of evidence to support its use, it may be appropriate to prescribe it to meet a patient's needs. The regulations governing the production of unlicensed medicines have, however, been tightened. Ensure that you:

• Are satisfied that an alternative, licensed medicine would not meet the patient's needs.
• Are satisfied that there is a sufficient evidence base and/or you have experience of using the medicine to demonstrate its safety and efficacy.
• Take responsibility for prescribing the unlicensed medicine and for overseeing the patient's care, including monitoring and any follow-up treatment.
• Record in the patient's notes the medicine prescribed and, where you are not following common practice, the reasons for choosing this medicine.

GPs should be aware that, if they prescribe unlicensed medicines, they take full clinical responsibility for any adverse events that occur.

Patient group direction^[5]

This is signed agreement, by a doctor, which allows a nurse to supply ± administer a prescription only medicine (POM) to patients without the nurse having to refer back to the doctor for each individual patient. This is limited to drugs used in a homogeneous group of patients (eg standard or travel immunisations, emergency hormonal contraception or analgesia before a minor procedure) where the presenting problems or the needs are likely to be highly consistent. The development of patient group directives is the responsibility of a senior doctor, senior pharmacist and senior nurse in a given area. A patient group directive is then drawn up at local level with a system of checks and balances to ensure its safety and appropriateness.

Particular patient groups

Pregnant women^[4]

Drugs are rarely implicated in congenital malformations. However, this should not be a cause for complacency. Bear in mind effects of drugs on any woman of childbearing age or any man trying to father a child. Use older drugs first-line as these will have a more detailed safety history; use the lowest effective dose.

• Drugs should be avoided if at all possible in the first trimester of pregnancy, unless the benefit to the mother outweighs the risk to the fetus. The period of greatest risk for teratogenesis is the third to the eleventh week of pregnancy.
• Drugs given during the second and third trimesters may affect the growth of the fetus or functional development or have a toxic effect on fetal tissue.
• Drugs given shortly before term can have an adverse effect on labour or on the baby after delivery.

A full list of drugs known to be harmful and not know to be harmful is available in Appendix 4 of the British National Formulary (BNF) but no drug is safe beyond all doubt in early pregnancy. Further information is available from the National Teratology Information Service.

Children

See separate article Prescribing in Children for more details.

Elderly

See separate article Prescribing for the Older Patient for more details.

Palliative care

See separate article Prescribing in Terminal Care for more details.

Difficulties with prescriptions

Side-effects and the Yellow Card Scheme^[6]

It is worth ensuring that the patient is aware of differences between adverse effects of drug and effects of disease, and any delays in beneficial effects. However, if you suspect that a given symptom is a side-effect, you may consider reporting this if:

• It is severe, eg anaphylaxis, blood disorders, severe CNS effects or skin reactions, endocrine dysfunction, etc.
• It is unexpected - see the BNF for more common or known severe reactions.
• This is a newly licensed drug (marked by an inverted black triangle); it is then worth reporting all side-effects, major or minor.
• A baby is born with congenital abnormalities. Consider whether this might be as a consequence of an adverse reaction to a drug. In this case, try to elicit a detailed account of all drugs (including self-medication) that a mother may have taken during her pregnancy.

Doctors, dentists, nurses and pharmacists are encouraged to report any such reactions directly to the Medicines and Healthcare products Regulatory Agency (MHRA) via the Yellow Card Scheme, which can be completed online (see link provided in Internet and further reading, below) or by post.

Drug interactions

Interactions may be:

• Pharmacodynamic - two or more drugs have similar or antagonistic properties.
• Pharmacokinetic - one drug alters the absorption, distribution, metabolism or excretion of another. The effect may be potentiating or antagonistic.

Many interactions are harmless but, if you have reason to be concerned, report any suspected drug interaction as you would an adverse effect, using the Yellow Card Scheme (see 'Side-effects and the Yellow Card Scheme', above).

Concordance^[7][8]

Between a third and a half of people with prescriptions for long-term conditions do not take their medicines as intended. The trend is to move away from compliance to concordance (ie obtaining the patient's collaboration by involving them in decisions about prescribing, taking due account of their personal, cultural and religious beliefs). This is one of the cornerstones of the Medicines Management Initiative, which is attempting to foster a closer partnership between the patients, clinicians and pharmacists concerning prescribing issues. Some measures can be taken to address concordance problems:

• It is good practice to have a system to check for prescriptions not collected or dispensed.
• Issues associated with poor compliance include lack of information about the purpose of a drug, how effective it is, the risk and severity of side-effects, and how to take it.
• Other issues included complicated methods of administration, unpleasant taste and physical problems such as swallowing difficulties or difficulties in opening the container.
• Discussing options will encourage the patient to seek alternatives rather than abandon the treatment altogether.
• Simplify drug regimes as much as possible (eg od rather than bd)
• Weigh up the benefits of combination preparations versus the problems of titrating individual drugs.

Other issues

Prescribing for self, family and friends^[3]

The GMC recommends that, as a general rule, you should avoid treating yourself, your family or persons with whom you have a close relationship. In their Good Practice guidelines, they specifically state that 'Controlled drugs can present particular problems, occasionally resulting in a loss of objectivity leading to drug misuse and misconduct'. They go on to state that you should only consider prescribing a controlled drug if:

• There is no other person with a legal right to prescribe and
• Treatment is immediately necessary to save life, avoid serious health deterioration or alleviate uncontrollable pain

You must record your actions and be able to justify them as well as record the circumstances that led to the situation.

Keeping up-to-date

It is incumbent on anybody prescribing medicines to keep up to date with the ongoing developments and ensure that your prescription is appropriate.^[3] There are many sources of information to support you in this, including the National Electronic Library for Medicines,^[9] the National Prescribing Centre^[10] and the BNF. If you are uncertain, stay on the safe side, consult a colleague or look it up.