An Introduction to An Introduction to PrescribingPrescribing

Narinder Bhalla

Lead Pharmacist – Clinical Governance

Addenbrooke’s NHS Trust

November 2006

ObjectivesObjectives

What is prescribing?What is prescribing? Responsibilities of the prescriberResponsibilities of the prescriber Good prescribing principlesGood prescribing principles Using the BNF and other info sourcesUsing the BNF and other info sources Principles of prescribing in special groupsPrinciples of prescribing in special groups

When it goes wrongWhen it goes wrong

What is prescribingWhat is prescribing

Writing/generation of a prescription for a drug (paper

or electronic).

Verbal order for a drug to be administered on doctor’s

advice.

Responsibilities of the prescriberResponsibilities of the prescriber

If you prescribe a drug you are clinically and legallyIf you prescribe a drug you are clinically and legally

responsible for your actions.responsible for your actions.

If you are asked to prescribe the drug, it is the person If you are asked to prescribe the drug, it is the person who signs the prescription who is responsiblewho signs the prescription who is responsible

Right PatientRight Patient Right DrugRight Drug Right DoseRight Dose Right Route Right Route Right TimeRight Time

Responsibilities of the prescriberResponsibilities of the prescriber

Responsibilities of the prescriberResponsibilities of the prescriber

Only prescribe medicines that you are competent to prescribe.Only prescribe medicines that you are competent to prescribe.

(knowledge of drug indication, action, dosing, side-effects, (knowledge of drug indication, action, dosing, side-effects, interactions).interactions).

Only prescribe medicines if they are necessaryOnly prescribe medicines if they are necessary

Prescribe only if benefits of medication outweigh the risksPrescribe only if benefits of medication outweigh the risks

Discuss treatment options with the patients/concordanceDiscuss treatment options with the patients/concordance

Indicate likely/degree of benefit (efficacy), onset and durationIndicate likely/degree of benefit (efficacy), onset and duration

Discuss side-effects/tolerabilityDiscuss side-effects/tolerability

Concordance Concordance (www.medicinespartnership.org)(www.medicinespartnership.org)

The prescriber and the patient should agree on the The prescriber and the patient should agree on the health outcomes and the strategy for achieving health outcomes and the strategy for achieving them. them.

Consider religious, cultural and personal beliefs Consider religious, cultural and personal beliefs that may affect acceptance of medicines. that may affect acceptance of medicines.

Keep drug regimes simple and review regularlyKeep drug regimes simple and review regularly

Combination treatments only if benefits outweigh Combination treatments only if benefits outweigh risks (restrict ability to titrate doses).risks (restrict ability to titrate doses).

Principles of Good PrescribingPrinciples of Good Prescribing

State patient details clearly (name, address, date of birth, age (children/elderly).State patient details clearly (name, address, date of birth, age (children/elderly).

Take account of any allergies and complete relevant paperwork.Take account of any allergies and complete relevant paperwork.

Use generic drug namesUse generic drug names

State drug, dose, strength, route and frequencyState drug, dose, strength, route and frequency

Avoid abbreviationsAvoid abbreviations

Avoid multiple route prescribing (i.e. im/sc/po)Avoid multiple route prescribing (i.e. im/sc/po)

State dose as grams, mg, mcg.State dose as grams, mg, mcg.

Make administration of once weekly drugs clearMake administration of once weekly drugs clear

Generic PrescribingGeneric Prescribing

Prescribe by the approved drug namePrescribe by the approved drug name

Ensures clarity regarding drug requiredEnsures clarity regarding drug required

Ensures that the most-cost effective version of the drug Ensures that the most-cost effective version of the drug can be supplied.can be supplied.

Commonly Used latin abbreviationsCommonly Used latin abbreviations

ac.ac. - ante cibum (before food)- ante cibum (before food)

bd.bd. - bis die (twice daily)- bis die (twice daily)

od.od. - omne die (once daily)- omne die (once daily)

om.om. - - -omni mane (every morning)-omni mane (every morning)

on.on. - omni nocte (every night)- omni nocte (every night)

tdstds - ter die sumendus (to be taken three times daily- ter die sumendus (to be taken three times daily

tidtid - ter in die (three times daily)- ter in die (three times daily)

pc.pc. - post cibum (after food)- post cibum (after food)

prnprn - pro re nata (when required)- pro re nata (when required)

qdsqds - quarter die sumendus (to be taken four- quarter die sumendus (to be taken four

times dailytimes daily

Types of prescriptionTypes of prescription

FP10 (white)FP10 (white)

Standard NHS prescription issued by GPs that canStandard NHS prescription issued by GPs that can

be dispensed by a pharmacy registered tobe dispensed by a pharmacy registered to

dispense NHS prescriptionsdispense NHS prescriptions

FP10(HP) YellowFP10(HP) Yellow

NHS prescription issued by hospitals, that can be NHS prescription issued by hospitals, that can be dispensed by a registered pharmacy.dispensed by a registered pharmacy.

FP10PFP10P

Nurse prescriber’s NHS prescriptions that can beNurse prescriber’s NHS prescriptions that can be

dispensed by a registered pharmacy.dispensed by a registered pharmacy.

Types of prescriptionTypes of prescription

Hospital prescriptionsHospital prescriptions

Outpatient clinic prescriptionsOutpatient clinic prescriptions

Main drug chartMain drug chart

Anticoagulant chartAnticoagulant chart

Diabetic chartDiabetic chart

IV chartIV chart

Factors affecting prescribingFactors affecting prescribing

Patient’s clinical statePatient’s clinical state Concomitant diseaseConcomitant disease Severity of current diseaseSeverity of current disease Available treatmentsAvailable treatments

(consider likely outcomes (patient oriented (consider likely outcomes (patient oriented outcomes)/quality of life).outcomes)/quality of life).

Likely efficacy of treatmentsLikely efficacy of treatments Side-effects/tolerabilitySide-effects/tolerability Interactions (drugs and food)Interactions (drugs and food) Compliance/health benefitsCompliance/health benefits

British National Formulary (BNF)British National Formulary (BNF)www.bnf.orgwww.bnf.org

Front sectionFront section Prescribing guidance, prescription writing & CD prescribing Prescribing guidance, prescription writing & CD prescribing Prescribing in children, elderly & palliative care Prescribing in children, elderly & palliative care Emergency treatment of poisoningEmergency treatment of poisoning

Middle sectionMiddle section Approved Drug Name with indications, S/E, cautions & doseApproved Drug Name with indications, S/E, cautions & dose

Back sectionBack section Appendixes: interaction, pregnancyAppendixes: interaction, pregnancy Abbreviations used in the BNF (BNF Back page) Abbreviations used in the BNF (BNF Back page)

BNF (www.bnf.org)BNF (www.bnf.org)The main text consists of classified notes on clinical conditions, drugs and preparations.The main text consists of classified notes on clinical conditions, drugs and preparations.

These notes are divided into 15 chapters, each of which is related to a particular systemThese notes are divided into 15 chapters, each of which is related to a particular system

of the body or to an aspect of medical care. of the body or to an aspect of medical care.

Chapter 1: Gastrointestinal systemChapter 1: Gastrointestinal system

Chapter 2: Cardiovascular systemChapter 2: Cardiovascular system

Chapter 3: Respiratory systemChapter 3: Respiratory system

Chapter 4: Central Nervous SystemChapter 4: Central Nervous System

Chapter 5: InfectionsChapter 5: Infections

Chapter 6: Endocrine systemChapter 6: Endocrine system

Chatper 7: Obs and Gynae and Urinary tract disordersChatper 7: Obs and Gynae and Urinary tract disorders

Chapter 8: Malignant disease and immunosuppressionChapter 8: Malignant disease and immunosuppression

Chapter 9: Nutrition and bloodChapter 9: Nutrition and blood

Chapter 10: Musculoskeletal and joint disordersChapter 10: Musculoskeletal and joint disorders

Chapter 11: EyeChapter 11: Eye

Chapter 12: ENTChapter 12: ENT

Chapter 13: SkinChapter 13: Skin

Chapter 14: immunological products and vaccinesChapter 14: immunological products and vaccines

Chapter 15: AnaesthesiaChapter 15: Anaesthesia

Drug listings in the BNFDrug listings in the BNFDrug Name

Indications: (details of use and indications)

Cautions: details of precautions required (with cross-references to appropriateAppendixes) and also any monitoring required.

Contra-indications: details of any contra- indications to use of the drug.

Side-effects: details of common and more serious side-effects.

Dose: dose and frequency of administration (max dose); Child and Elderly details of

dose for specific age group.

By alternative route, dose and frequency.

Approved name: form, pack size and price.Proprietary name: form, pack size and price.

BNF AppendixesBNF Appendixes

Appendix 1-Drug InteractionsAppendix 1-Drug Interactions A black dot symbol A black dot symbol is placed against those interactions is placed against those interactions

that are potentially hazardous.that are potentially hazardous.

Interactions listed by drug/drug class in alphabetical Interactions listed by drug/drug class in alphabetical order.order.

BNF AppendixesBNF Appendixes

Appendix 2Appendix 2 Table of drugs to be avoided or used with caution in liver Table of drugs to be avoided or used with caution in liver

diseasedisease

Appendix 3Appendix 3 Principles of dose adjustment in renal impairmentPrinciples of dose adjustment in renal impairment GFR valuesGFR values Table of drugs to be avoided or used with caution in Table of drugs to be avoided or used with caution in

renal impairmentrenal impairment

BNF AppendixesBNF Appendixes

Appendixes 4 and 5Appendixes 4 and 5 Prescribing in pregnancy and breast feedingPrescribing in pregnancy and breast feeding

Appendix 6Appendix 6

Intravenous additivesIntravenous additives Table of common drugs given IV and how toTable of common drugs given IV and how to

prepare, dilute and administer them.prepare, dilute and administer them.

Yellow Card ReportingYellow Card Reporting

Doctors, nurses, pharmacists and patients mayDoctors, nurses, pharmacists and patients may

complete a yellow card reportcomplete a yellow card report

ReportReport

1. All suspected reactions to new medicines (black triangle)1. All suspected reactions to new medicines (black triangle)

2. All serious suspected reactions to established medicines2. All serious suspected reactions to established medicines

3. Report all serious and minor reactions in children (<18yrs).3. Report all serious and minor reactions in children (<18yrs).

Sources of Prescribing InfoSources of Prescribing Info

Trust Prescribing PolicyTrust Prescribing Policy BNF/eBNFBNF/eBNF IV guides/monographsIV guides/monographs Trust FormularyTrust Formulary Specialist references (e.g. Paediatric)Specialist references (e.g. Paediatric) Summary of Product CharacteristicsSummary of Product Characteristics PharmacistPharmacist Medicines InformationMedicines Information Electronic access to central library of Trust approved Electronic access to central library of Trust approved

guidelines.guidelines.

Prescribing for childrenPrescribing for children

Children are not little adultsChildren are not little adults

Many drugs not licensed for use in childrenMany drugs not licensed for use in children

Use a specialist children's formulary “BNF for Children”.Use a specialist children's formulary “BNF for Children”.

Weights and occasionally surface areas are requiredWeights and occasionally surface areas are required to calculate accurate doses. These parameters may to calculate accurate doses. These parameters may

change significantly in a relatively small time period.change significantly in a relatively small time period.

Prescribing for ChildrenPrescribing for Children

Pharmacokinetic changes in childhood are important and Pharmacokinetic changes in childhood are important and have a significant influence on drug handling.have a significant influence on drug handling.

The availability of a product does not ensure its suitability The availability of a product does not ensure its suitability for use in children.for use in children.

Prescribing for the ElderlyPrescribing for the Elderly

18% of the population are over 65yrs age.18% of the population are over 65yrs age. Receive 1/3 of NHS prescriptionsReceive 1/3 of NHS prescriptions Absorption, metabolism, distribution and elimination of Absorption, metabolism, distribution and elimination of

drugs affected by ageing.drugs affected by ageing. Renal function deteriorates with age.Renal function deteriorates with age. Alzheimer’s disease, dementia and other cognitive Alzheimer’s disease, dementia and other cognitive

disorders, Parkinson's disease are important disorders in disorders, Parkinson's disease are important disorders in the elderly.the elderly.

Drugs such as NSAIDS, opioids, benzodiazepines etc Drugs such as NSAIDS, opioids, benzodiazepines etc are likely to cause problems in the elderly.are likely to cause problems in the elderly.

Prescribing for the ElderlyPrescribing for the Elderly

Principles of prescribingPrinciples of prescribing Avoid unnecessary drug therapyAvoid unnecessary drug therapy Effect of treatment on quality of lifeEffect of treatment on quality of life Treat the cause rather than the symptomTreat the cause rather than the symptom Drug historyDrug history Concomitant medical illnessConcomitant medical illness Choice of drugChoice of drug Dose titrationDose titration Dosage formDosage form Packaging and labellingPackaging and labelling Good record keepingGood record keeping Regular reviewRegular review

Formularies & ‘Essential’ DrugsFormularies & ‘Essential’ Drugs

National formulariesNational formularies (e.g. the BNF) (e.g. the BNF) provide an independent source of advice.provide an independent source of advice.

Hospital formulariesHospital formularies reflect hospital choices, based on evidence reflect hospital choices, based on evidence based and cost-effective evaluation of the evidence base for a drug.based and cost-effective evaluation of the evidence base for a drug.

WHOWHO provide a ‘model’ list of essential drugs (~300 items). provide a ‘model’ list of essential drugs (~300 items).

Common Prescribing ErrorsCommon Prescribing Errors

Wrong drug (e.g. drugs that sound alike)Wrong drug (e.g. drugs that sound alike) Wrong dose Wrong dose Inappropriate UnitsInappropriate Units Poor/illegible prescriptionsPoor/illegible prescriptions Failure to take account of drug interactionsFailure to take account of drug interactions OmissionOmission Wrong route/multiple routes (IV/SC?PO)Wrong route/multiple routes (IV/SC?PO) Calculation errors (important in Paediatrics)Calculation errors (important in Paediatrics) Poor cross referencingPoor cross referencing Infusions with not enough details of diluent, rate etc. Infusions with not enough details of diluent, rate etc.

Poor cross-referencing between chartsPoor cross-referencing between charts Once weekly drugsOnce weekly drugs Multiple dose changesMultiple dose changes