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Introduction to Primary Care: a course of the Center of Post Graduate Studies In FM

Rational Drug Rational Drug PrescriptionPrescription

Rabwa Postgraduate CenterPO Box 27121 – Riyadh 11417Tel: 4912326 – Fax: 4970847

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How to Prescribe Safely

Clare HughesTeacher Practitioner Pharmacist

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Aims of talk….

• Evaluate the need to reduce risk from prescribing medicines

• Discuss the importance of safe prescribing• Identify ways of improving prescribing• Describe the NHS plan and the role of the

NPSA• Identify sources of information which will help

you prescribe safely

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What’s this got to do with you ?

• You will be responsible for prescribing• You will make prescribing errors• You need to be aware of potential pitfalls• You need to think about prescribing safely• You need to know when to ask for help

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What is a medication error ?

‘ a medication error is any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of health professional, patient or consumer’

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Incidence of errors

• The incidence of medication errors in the NHS is unknown

• ~10-20% of all ADRs are due to errors • In USA 1.8% of hospital admissions have a

harmful error leading to 7000 deaths per year• In Australia – 1% of all admissions suffer an

ADR due to medication error

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Common error types?

• Wrong patient• Contra-indicted

medicine• Wrong drug /

ingredient• Wrong dose / freqency• Wrong formulation• Wrong route of

administration

• Poor handwriting on Rx• Incorrect IV

administration calculations or pump rates

• Poor record keeping• Paediatric doses• Poor administration

techniques

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Examples….

• Insulin written 7☉ stat given – 70 units given instead of 7 units

• Erythromycin 500mg iv prescribed in 50ml– vein necrosis should be in 250-500ml

• ISMN mistaken for ISTIN• Vancomycin IV bolus rather than infusion –

cardiac arrest

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• Digoxin 125mg IV not micrograms – cardiac arrest

• Double rate of aminophylline infusion given – vomiting

• Weight related clexane – 80kg estimates – pt weighed 51kg

• Levothyroxine missed on admission – discovered day 10

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Case 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, comp. record

unaltered• +5/7 patient admitted to ENT ward

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• 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

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Case 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, postponed

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

to admin intrathecal drug• anaesthetist given I/Thecal but never given

chemotherapy• Methotrexate given intravenously• Vincristine given intrathecally• Patient died

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Commonest causes of medication errors• Lack of knowledge of the drug – 29%• Lack of knowledge about the patient – 18%• “rule” violations – 10%• “Slip” or memory loss – 9%

JAMA 1995;274:35-43

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Legal aspects

• Prescribing covered by Medicines Act 1968

• Increasing range of prescribers• If prescribed as per SPC,

manufacturer holds liability• Medicines without a marketing

authorisation• Medicines prescribed off label

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An organisation with a memory (NHS)• 400 deaths/yr – medical devices• 10,000 serious ADRs / year• 28,000 written complaints/yr• NHS spends £400M a year on clinical negligence claims• Hospital acquired infection costs £1Bn a year (15% may

be avoidable)THESE DO NOT GIVE THE TRUE SCALE OF THE

PROBLEMSDepartment of Health 1999

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NHS Goals

• Reduce to zero the number of patients dying or paralysed by maladministered spinal injections by end 2001

• Reduce by 40% the number of serious errors in the use of prescribed medicines

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National Patient Safety Agency

• Collect and analyse information on adverse events• Assimilate other safety-related information• Learn lessons and ensure that they are fed back

into practice• Where risks are identified, produce solutions to

prevent harm, specify national goals and establish mechanisms to track progress

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Prescribing responsibilities

• Drug• Dose• Route• Frequency• Rate of administration• Duration of treatment• Allergies and

sensitivities

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• Provide a prescription that is

– LEGIBLE (!!!!!)– Legal– Signed– Giving ALL

information to allow safe administration

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Controlled drugs

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Drug history taking

• Current medication– Dose– Form– Strength– Frequency– Indication

• Past medication and Tx failures

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• Over the counter medication• Recreational drugs• Adverse reactions• Allergies and sensitivities• What was the allergy• Estimate of compliance

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Information Sources

• GP letter – may be inaccurate / incomplete• Printed GP letter – may not be up to date• Patients own tablets• Written lists

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Common pitfalls

• No direction on label• Not brought any of own tablets in• No / unclear strengths eg inhalers• Trade names – beware duplicates• Patient can’t remember• GP records out of date• Dosette boxes – tablet ID

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Safe prescribing

• Clear and unambiguous• Use approved names• No abbreviations eg ISMN• Unless G or mg then write units in full

(micrograms or nanograms)• Avoid decimal points – if needed then make

very clear (0.5ml NOT .5ml)

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• Rewrite charts regularly• If amend prescription re-write or sign and date

amendment• For frequency use standard abbreviations eg

od / bd / tds etc• If using a dose by weight calculate the dose

needed (NOT 1.5mg/kg)• Take time (e.g. to read patient information)

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Take extra care if:

• Impaired renal function• Hepatic dysfunction• Children• The elderly• Drug unknown to you• Very new drug

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How can we help you ??

Clinical Pharmacists• View charts daily• Check doses etc• Check interaction• Check appropriateness• Provide advice and

information

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Medicines Information

• All hospitals have • At end of phone• Answer all queries

large or small• There to help you

prescribe safely

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Prescribing guidelines and resources• Developed to

standardise treatment• Evidence based use of

medicines• Try and familiarise

yourself with these• Often now on intranets

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Summary

• Provide a clear, unambiguous and legal prescription

• When in doubt - ASK

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Prescribing Quiz

• Teams of 4/5 people• If need additional

information write ‘need info on . . .’

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Question 1

A frail 80 year old lady is admitted with falls, a chest infection and feeling sick. PMH – AF and Hypertension The medication history is recorded as:

Bendroflumethazide 5mg dailyAtenolol 50mg dailyRamipril 1.25mg dailyAspirin 75mg dailyWarfarin 3mg dailyDigoxin 250 micrograms daily

She was started on Benzylpenicillin IV 2.4G qds and Ciprofloxacin po 400mg bd

List 5 potential problems with this prescription….

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Question 2

A patient has come in with RTI and has the following on the drug chart.

Benzylpenicillin 2.4G IV qdsCiprofloxacin 750mg bd

The patient has had the antibiotics for 2 days is better and ready for discharge – write a TTO

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Question 3

A patient is admitted on-call via GP. The GP letter states that the patient is currently receiving:

ISMN 60mg / dayNifedipine 30mg /dayAtorvastatin 30mg / day

Fill in the ‘in-patient’ drug chart for this patient

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Question 4

NHS goal – how much do the number of serious errors in the use of prescribed medicines need to reduce by ?

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Question 5

Give the generic names of the following• Zocor• Tegretol• Istin• Losec

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Question 6

A patient is going home and needs the following:

MST 30mg bd for 14 days

Please write the prescription (excluding name and address)

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Question 7

A patient needs Vancomycin 500mg bd IV

Write up in patient drug chart

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Question 8

Patient is due to go home and has the following on in patient Rx:Amiodarone 200mg tds (started 4 days ago)Simvastatin 10mg onFurosemide 40mg bd (for post-op peripheral oedema)Zopiclone 7.5mg on (started in hospital)Write patients TTO for 1 mth

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Question 1A frail 80 year old lady is admitted with falls, a chest infection and feeling sick. PMH – AF and Hypertension The medication history is recorded as:

Bendroflumethazide 5mg daily Dose for HTN 2.5mgAtenolol 50mg daily ?causes of fallsRamipril 1.25mg daily Dose of ciprofloxacin – 750mg bdAspirin 75mg daily Aspirin and warfarin interactionWarfarin 3mg daily Warfarin and antibiotic interactionsDigoxin 250 micrograms daily Dose of digoxin too high

She was started on Benzylpenicillin IV 2.4G qds and Ciprofloxacin po 400mg bd

List 5 potential problems with this prescription….

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Question 2

• Amoxycillin 500mg tds for 5 days• Ciprofloxacin 750mg bd for 5 days

• -1 if unsigned

• Max 2 marks

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Question 3

• Isosorbide mononitrate MR 60mg prescribed at 8am

• Nifedipine 30mg MR prescribed daily• Atorvastatin 30mg prescribed at night• -1 mark if no signatures included• -1 mark if no routes included

Max 3 marks

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Question 4

40%

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Question 5

• Zocor = simvastatin• Tegretol = carbamazepine• Istin = amlodipine• Losec = omeprazole

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Question 6

Morphine (Sulphate) MR (SR) tablets 30mg BD (for 14 days)

28 (twenty eight) x 30mg

(840mg – eight hundred and forty milligrams)

Signed dated and print name

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Question 7Drug Vancomycin

8 x

Dose 500mg

Route IV

Start Date  

Stop Date 12  

Signature Squiggle

Pharm 18 x

Additional instructions In 100mls NaCl 0.9% over 60 mins

24  

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Question 8

• Amiodarone 200mg tds for 4 days then bd for 7 days then daily

• Simvastatin 10mg on• Frusemide 40mg bd for <7 days then to be

reviewed by GP- will accept 40mg om as dose change- No zopiclone required as started in hospital