Safe prescribing:How to avoid prescribing errors

Kevin GibbsClinical Pharmacy ManagerUnited Bristol Healthcare Trust

Aims

To provide an awareness of: Common medication errors How to minimise these National and local resources available

to you to aid in safer prescribing To give you some prescribing

pointers to look out for in your clinical placements

By the end of the session you should be able to: Define a medication error List the ‘Five Rights’ Identify common types of medication

errors Begin to think about how to minimise

errors by using your knowledge, skills and available resources

During your placementsThink about:

What do I need to prescribe in a safe way? Patient information

Co-morbid conditions Drug information

Pharmacology Pharmacokinetics and pharmacodynamics Therapeutics

Systems Policies, guidelines, prescribing aids etc

What is an error?

What is an error ?

Doses omitted Wrong dose Unprescribed drug

given Wrong dosage form

given Wrong route of

administration Wrong rate of

administration

Wrong time of administration time of day in relation to food

etc.... Using

unstable/expired drug Wrong administration

technique Incorrect

reconstitution Extra dose given

Where do errors occur in the process of giving a drug?

Prescribing Dispensing Administration Counselling/communication

Adverse events in hospitalsWhat is the size of the problem?

Adverse events per admission (%)

10%

AE number / year in UK 850,000

Cost in additional hospital stay (£)

£2 billion

Cost of clinical negligence schemes/yr

£400 million

Medication errors = % of incidents

25%

An organisation with a memory. Dept of Health 2001

Reported incidences

Difficult to estimate due to varying definitions - US/UK

Prescribing errors 3-20 per 1000 prescriptions

Medication errors 1 per patient per day

Been estimated that drug errors account for 1/5 of all deaths due to adverse drug events

Outcomes

Data collated by US National Co-ordinating council for Medication Error Reporting and Prevention 1993-98 Performance deficit

29.8% Communication

problem 15.8% Knowledge deficit

14.2% Dose miscalculation

13%

5366 reports 68.2%- Serious patient

outcomes 9.8% - fatal

Improper dose Wrong drug Wrong route of

administration

Phillips, J etal. Am J Health Syst Pharm 2001;58: 1835-41

Prescribing errors

Process Error Rate Serious Errors

Prescribing errors(Primary Care)

Computer generated

7.9%

Prescribing errors(Primary Care)Hand written

10.2%

Prescribing errors(Hospital)

1.5% 0.4%

Dean B, Schachter M, Vincent C, Barber N. Quality and Safety in Healthcare 2002; 11:340-344Shah SNH, Aslam M and Avery AJ. Pharm J. 2002; 267: 860-862

Handwriting

Errors in medication history taking

Literature review 22 studies, 3755 patients

Errors in medication histories In up to 67% of cases 10-61% had at least 1 omission error 54% of patients had at least 1

medication history error Clinically important errors in 11-59%

Tam et at Canadian Medical Association Journal 2005;173(5):510-15

Dispensing and adminn errors

Stage of process Error Rate Serious Errors

Dispensing errors (P) 1% 0.18%

Dispensing errorsUndetected (H)

0.0002

AdministrationOral Medicines (H)

3 – 8%

Preparation and admin of parenteral medicines

13%- 49% 1%

UK references 1 – 12 from Building a safer NHS, Medication Safety

Similar packaging

Same drug – different manufacturers

Similar packaging

Same drug – several strengths May be colour-coded but DO NOT rely on

colour

Similar packaging

Similar sounding names / similar spelling / same strength

Ceftazidime – Cefotxime

Similar packaging

If in a hurry – These look similar Water for injection, Sodium Chloride injection

So does Potassium 15% injection = Why there are NPSA/Trust policy on restricting this

Summary:Common error types

Wrong patient Contra-indicated medicine

Allergy, medical condition, drug-drug interaction

Wrong drug / ingredient Wrong dose / frequency Wrong formulation Wrong route of administration Wrong quantity

Poor handwriting on Rx Incorrect IV administration

calculations or pump rates Poor record keeping/checking

double doses wrong patient

Paediatric doses Poor administration technique

Complicated prescriptions Calculations Verbal orders Lack of knowledge about drugs Mistakes in identifying drugs

names packaging misreading

National & local examples

Discharged on warfarin loading dose 10mg od

Not referred for dose adjustment to clinic

14days of 10mg od

INR 12.3

Admitted with frank haemorrhage

Weight-related dose for tinzaparin – 80kg estd

Patient was 51kg, risk of haemorrhage

Rx: Ranitidine 50mg Given via epidural line rather than central line

Discharged on warfarin loading dose 10mg od

Not referred for dose adjustment to clinic

14days of 10mg od

INR 12.3

Admitted with frank haemorrhage

Weight-related dose for tinzaparin – 80kg estd

Patient was 51kg, risk of haemorrhage

Rx: Ranitidine 50mg Given via epidural line rather than central line

CABG patient, standard therapy

Thyroxine missed on admission, discovered day 10

Galantamine re-started after a gap, Rx; 8ml qds

Should have been 12mg (2ml) bd

prescriber confused over liquid strength

Rx: Co-amoxiclavPenicillin-alllergic

Did not realise this is a penicillin

anaphylaxis

Anaesthetist adjusted rate of fentanyl syringe pump in Theatre

New pump. Increased rate x 1000

Respiratory arrest - death

Rx: morphine 0.4ml 4ml given

30% sodium chloride used instead of 0.9% to dilute an epidural

Severe pain

In Theatre: Sodium chloride flush for a central line switched with fentanyl

Respiratory arrest. Syringes made up in advance and not labelled

IV line flushed with sodium chloride 0.9%

Was in fact Potassium 15%

→ deathAmpoules look similar in design

Case study 1 – "Cambridge"

Rx Methotrexate 17.5mg once a week

New Rx 10mg once a day 10mg daily dispensed by locum

pharmacist Rx error noticed by 2nd GP, but the

computer record was not altered +5/7 patient admitted to ENT ward

Drug chart written for 100mg daily +1/7 Nurse d/w patient – back to 10mg

od +1/7 Pharmacist queries and asks

nurse to ask Dr to check dose GP records confirm 10mg od +2/7 blood tests re-checked Haem +5/7 patient dies

Case study 2 – “Nottingham”

Rx Intrathecal methotrexate under GA in theatre by Oncology Reg & intravenous vincristine on ward by specialist nurse

"Outlied" on non-specialist ward Both drugs delivered to theatre from

ward Given food pre-op – op postponed

Orignal SpR off-duty now Cover SpR unable to leave ward,

anaesthetist to admin intrathecal drug Aneasthetist had given I/Thecal drugs

before but had never given chemotherapy

Methotrexate given intravenously Vincristine given intrathecally Patient died

Improving medication safety

Department of Health. Jan 2004

Improving medication safety:Main areas of medication error

Anaesthetic practice Anticoagulants Cytotoxic drugs Intravenous infusions Methotrexate Opiate analgesics Potassium chloride

Causes → Solutions

Lack of knowledge of the drug – 31%

Wrong dose, choice, drug.

Interaction Allergy checking

“rule” violations – 10% Incl. communication

problems

“Slip” or memory loss – 9%

Drug information Eg: Interactions

Resources available Patient condition Renal / liver function

Guidelines, formulary

Leape et al. JAMA 1995;274:35-43

Avoiding errors

Patient knowledge Have a therapeutic goal

Is prescribing the right answer? Have you included the patient in this decision?

Knowledge about the drug Monitor for effects and adverse effects Use your resources Good communication

Taking a good medication history

How reliable is your source – does it have enough detail?

Patient, patient’s repeat prescription, own drugs, GP admission letter, on-call service

Drug details dose, frequency, formulation (eg modified

release), start date, indication Include: Prescribed drugs, ‘OTC’ drugs,

complementary medicines, vitamins, ? ‘Recreational drugs’

Allergies including severity Compliance Therapeutic failures

Factors affecting a drugs pharmacodynamics or pharmacokinetics

Children The elderly Renal impairment Hepatic impairment Prescribing in pregnancy or breast feeding Drug interactions

More later…..

Further references:Clinical Pharmacology textbook – use course recommendationBasic Clinical Pharmacokinetics. 4th edn. ME Winter. Covers Drug-specific kinetics eg Digoxin, gentamicin

Drug dosing in renal impairment

Based on estimation of renal function using creatinine clearance Cockcroft-Gault equationCrcl = F x (140-age)x wt in kg

S.Cr in micromol/LWhere F = 1.23 for males, 1.04 for females

Or use an on-line calculator such as http://www.kidney.org/professionals/kdoqi/gfr_cal

culator.cfm

Drug-drug interactionsdrug-food interactions

Resources BNF Appendix 1 Pharmacy Medicines Information

Departments Have specialists texts and other

resources to help

mOre in a leter talk

Resources available to you

Summary of Product Characteristics for each medicine - eMC

Pharmacy Medicines Information On-line National Electronic prescribing Other medical and non-medical

prescribers

Pharmacy

Avaliable for help and advice Ward Pharmacist Local Medicines Information

department Regional medicines Information

Mainly Community sector enquiries Out-of-hours: On-call or resident

pharmacist

Electronic Medicines Compendium (eMC)

The eMC provides up-to-date information on licensed UK medicines http://emc.medicines.org.uk/ Summary of Product Characteristics (SPCs) Patient Information Leaflets (PILs).

SPCs are legal & technical documents with information to help guide on the best way to use a medicine.

In summary

Prescribing responsibilities

Drug Dose Route Rate of administration Duration of treatment

Checking patient allergies & sensitivities

Providing a prescription that is: Legible Legal Signed Giving all information to allow safe

administration

Hints

Clear and unambiguous

Approved name

No abbreviations

Care with IVs

Care with units

Legal

Is it weight/BSA-related dosing. Is weight accurate?

Clear decimal points0.5ml not .5ml

Rewrite charts regularly

Take time, eg to read labels

Avoid abbreviations

od / bd / tds / qds

Not 250mg3

Take particular care if: Impaired renal function Hepatic dysfunction Children The elderly Drug is unknown to you Very new drug

Remember the “Five Rights”

• the right patient• the right drug• the right time• the right dose• the right route

If in doubt ……..

Ask

Further reading & resources

Naylor, R. Medication Errors. Radcliffe Press. ISBN 1857759567

Department of Health. (2004). Building a safer NHS. Improving medication safety.

http://www.dh.gov.uk/PublicationsAndStatistics/Publications/PublicationsPolicyAndGuidance/PublicationsPolicyAndGuidanceArticle/fs/en?CONTENT_ID=4071443&chk=PH2sST

National Patient Safety Agency Website: http://www.npsa.nhs.uk/

National Prescribing Centre Website: http://www.npc.co.uk/

Institute for Safe Medication Practices (ISMP) (American) Website: http://www.ismp.org/

National Electronic Library for Medicines Website:

http://www.druginfozone.nhs.uk/home/default.aspx

Aronson & Richards. Oxford Handbook of Practical Drug Therapy. ISBN 0198530072