Download National Medicines Information Centre MEDICATION SAFETY

National Medicines
Information Centre
ST. JAMES’S HOSPITAL • DUBLIN 8
TEL 01-4730589 or 1850-727-727 • FAX 01-4730596 • www.nmic.ie
VOLUME 10 NUMBER 6 2004
For Personal Use Only. Not to be reproduced without permission of the editor
MEDICATION SAFETY
SUMMARY
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Prescription of medicines is the commonest healthcare intervention
Prescribing is controlled by legislation
Adverse drug reactions and medication errors are the commonest cause of preventable
iatrogenic disease
The ICGP and NMIC have developed medication record cards to promote medication
safety.
INTRODUCTION
The prescribing of medicines is the commonest healthcare intervention in developed countries.1 However
drug-related adverse effects (so-called ADRs) are a significant cause of morbidity and/or mortality. It has
been estimated that up to 98,000 deaths from medical error occur in the US each year2 and a recent UK
study has shown that ADRs were responsible for >6% of hospital admissions.3 Rational prescribing may be
defined as the appropriate use of medicines, using best available clinical evidence.4 This bulletin outlines
the rules of prescribing, the risks for developing ADRs and specifically looks at a recent joint initiative
between the Irish College of General Practitioners (ICGP) and the National Medicines Information
Centre (NMIC) aimed at improving medication safety and anticoagulant use.
PRESCRIPTION REGULATION
The EU has laid down rules on the classification of medicines5 that have been incorporated into national
legislation. The supply of medicines to the marketplace in Ireland is controlled by The Medicinal Products
(Prescription and Control of Supply) Regulations, 2003.6 The Regulations outline several different
classifications (“Schedules”) relating to the supply of medicines to the market. The First Schedule (S1)
lists all medicines subject to prescription control; this is further subdivided into three classes (S1A, S1B,
S1C) which have implications for the way a prescription should be written and dispensed. Table 1 gives
examples of the various sub-divisions in the First Schedule. The dispensing of a prescription for a S1A
medicine is restricted to one occasion only unless the prescriber specifically states that it can be dispensed
on more than one occasion. It is not sufficient to write “repeat” on the prescription for S1A medicines;
specific dosages, and either the number of occasions or the intervals of supply (e.g. weekly / monthly)
must be clearly specified. S1B contains those medicines for which a prescription may be repeated for up to
six months from the date of issue, unless the prescriber specifically limits the number of repeats or the
amount to be dispensed. S1B includes most medicines for chronic use. S1C indicates a prescription that
may only be dispensed in a hospital setting (e.g. radio-pharmaceuticals) and therefore is not used in the
primary care setting. Table 2 outlines the basic requirements of a prescription.
The Regulations also cover the following areas: medicines which are exempt from prescription control (i.e.
for over-the-counter sale) and the circumstances of their sale and supply (e.g. NSAIDs and anti-fungal
agents for topical use); the controls for hormonal preparations, including corticosteroids for topical use;
the mechanism for the emergency supply by a pharmacist of prescription-only medicines without a
prescription. The complete text of the Regulations, including a full listing of all prescription-only
medicines is available at: www.dohc.ie/legislation/statutory_instruments/2003 (look for SI 540, 2003).
Table 1: Legal Classification of Medicines in Ireland: examples of prescription-only
medicines (POM)
Drug Name
Schedule Classification
Method of Supply
Anti-microbial agents
S1A
POM (restricted repeat)*
All parenteral medicines**
S1A
POM (restricted repeat)*
Benzodiazepines***
S1A
POM (restricted repeat)*
Methotrexate / ciclosporin
S1A
POM (restricted repeat)*
Anti-diabetic agents
S1B
POM (repeatable X 6mths.)
Anti-hypertensive agents
S1B
POM (repeatable X 6mths.)
NSAIDs
S1B
POM (repeatable X 6mths.)
Proton pump inhibitors
S1B
POM (repeatable X 6mths.)
*repeated only if prescription specifically worded
** except insulin which is in Schedule S1B
***flunitrazepam/temazepam also subject to prescription writing requirements under the Misuse of Drugs
Regulations (see below)
PRESCRIPTION OF CONTROLLED DRUGS
The Misuse of Drugs Regulations (1988; 1993)7 set out the conditions under which controlled drugs may
be produced, possessed, supplied, imported or exported. Controlled drugs are classified into five
schedules with different controls applying to each. Opiates and synthetic narcotics for medicinal use (e.g.
pethidine, methadone and buprenorphine) are contained in Schedule 2 and are termed CD2 drugs.
Prescriptions for controlled drugs carry additional requirements to those outlined in Table 2. These
include the following:
The prescription must be in ink or otherwise to be indelible. Certain minimum information must be in the
prescriber’s own handwriting such as the name and address of the patient, the dose to be taken, the form
(in the case of preparations), the strength (when appropriate) and, in both words and figures, either the
total quantity of the drug or preparation or the number of dosage units to be supplied. The prescription
must also be signed and dated by the prescriber in his own handwriting. A prescription for controlled
drugs cannot be repeated but may be dispensed in installments by the direction of the prescriber.
Computer-generated prescriptions without the above information in the prescriber’s own handwriting are
not acceptable.
Table 2: Basic requirements of a prescription
- Prescription must show the qualifications of prescriber*
- Prescription should be written in ink / be indelible (including computer-generated prescriptions)
and be signed and dated by the prescriber
- Full name, address of patient and date of birth (if <12 years) should be included
- Writing should be legible
* only registered doctors or dentists are allowed to prescribe in Ireland.
ADVERSE DRUG REACTIONS/MEDICATION ERRORS
Medicines not only have the ability to produce therapeutic benefit (the rationale for their prescription),
they can cause unwanted or unexpected adverse reactions. The EU definition of an adverse drug reaction
(ADR) is a response to a medicinal product which is noxious and unintended and which occurs at doses
normally used in man for the prophylaxis, diagnosis or therapy of disease or for the restoration, correction
or modification of physiological function.8 The majority of ADRs are predictable (i.e. from the
pharmacological profile) and are commonly dose-dependent (Type A). Type A reactions account for up to
80% of ADRs. Type B reactions are idiosyncratic, unpredictable and usually independent of dose; they
tend to have greater morbidity and potential mortality. Factors that are known to increase the risk of an
ADR include: 1) extremes of age, 2) underlying poor health status, 3) female gender and 4)
polypharmacy (defined as the concurrent use of five or more medicines) which results in increased
potential for drug-drug interaction.9
ADRs that occur in the primary care setting can result in hospital admissions / Accident and Emergency
consultations or use of other healthcare services. The exact number of ADRs experienced by patients is
unknown but a recent study involving two large UK hospitals reported that 6.5% of admissions were
related to ADRs, which was the direct cause of admission in 80% of these cases.3 Most reactions were
either definitely or possibly avoidable. Drugs most commonly implicated included warfarin, diuretics,
low dose aspirin and NSAIDs, with gastrointestinal bleeding being the commonest adverse reaction.
Medication errors may be defined as any error in the prescribing, dispensing or administration of a drug,
whether there are adverse consequences or not.10 They are reported to be the commonest preventable cause
of patient injury.11 In one US study the rate of serious medication error (i.e. preventable ADRs plus
potential adverse drug events) was recorded at 7.3%.12 Medication errors have been reported to account for
approximately 10-20% of legal claims against general practitioners.11 Prescribing errors may arise from
incorrect drug selection for a patient in terms of dose, strength, route, quantity or contra-indications. A
recent Irish study showed that 5% of prescriptions reviewed were illegible, another major source of
medication error.13 Table 3 outlines ways of reducing prescribing errors.
Table 3. Points to remember when writing a prescription
- Check dosing, contraindications and potential side effects (e.g. from the Summary of Product
Characteristics14 or in a recognised formulary, such as the BNF) prior to issuing prescription
- Check what other medicines the patient is taking, including non-prescription items, which may
interfere with the new medicine
- Refer to check list of common drug-drug interactions, when patients are taking several medicines
- Ensure that the prescription is legible – it may be misinterpreted if it cannot be read
- Advise patients of possible, likely and probable side effects and encourage them to report back
any problems
- Respond promptly (either reducing dose / discontinuing drug) to a patient’s concern /ADR
- In the event of any side effect, consider reporting it to the regulatory authority (www.imb.ie for
downloadable form)
IMPROVING MEDICATION SAFETY
The number of patients on complex medication regimens is increasing. Many currently approved regimens
demand that patients should take several medicines with differing modes of action (e.g. combined therapy
for hypertension15; use of several medicines in the secondary prevention of cardiovascular disease16). This
increases the risk of developing ADRs. In addition, it is often difficult to keep accurate records if a patient
attends both primary and secondary care facilities, or if a patient has more than one prescribing doctor.
Patients may be unaware of the name or type of medicine prescribed by another physician and this can lead
to the risk of an ADR or medication error.
Involving patients in their own drug treatment has been shown to increase compliance.17,18 Advising
patients, in advance, that they may experience a side effect, inviting them to report such side effects
promptly and having a planned course of response is important and will help to reduce the impact of
ADRs.
COMBINED ICGP/ NMIC SAFE MEDICATION INITIATIVE
To address the issue of improving medication safety, a joint initiative was undertaken recently by the ICGP
and the NMIC. The objective of this initiative was to produce two simple, user-friendly cards, chiefly with
a view to improving communication between different prescribers / care-givers in the management of
patients requiring several medications or anticoagulation therapy. The cards are designed to be handbag /
inside-pocket size and are not designed as a complete record of patient information.
MEDICATION CARD
ANTICOAGULATION CARD
These cards may be obtained from the ICGP at (01) 6763705 (small fee applies). They are particularly
relevant in the care of older patients, on polypharmacy, who are at significantly greater risk and more
vulnerable to toxicity from prescribing errors. A simple rule-based approach could be introduced into
primary care practices, in instances where patients are prescribed five or more medicines. Such patients (or
their carer) might be issued with a card. It should be noted that issuing the card initially involves a time
cost; however once set up, the card is easy to maintain, and greatly reduces the time taken to subsequently
review medications during later consultations. The introduction of these cards will also be of benefit at
outpatient visits, to colleagues on call and to practice locums.
SUMMARY
Improving safety in the prescribing, dispensing and administration of medicines is a priority for health
services throughout the world and many countries have put in place strategies to deal with this issue.19
Many of these provide good practice recommendations in areas that are known to be error prone. The use
of the ICGP/NMIC medication and anticoagulation cards aims to tackle these two main areas of potential
problems in prescribing. In addition, by involving patients, these cards will increase patients’ awareness of
their medicines which should increase compliance and improve medication safety.17
References available on request. Date prepared: March 2005
Every effort has been made to ensure that this information is correct and is prepared from the best available resources at our disposal at the time of
issue. Prescribers are recommended to refer to the drug data sheet or summary of product characteristics (SPC) for specific information on drug use.
References for NMIC bulletin 2004;10(6) “Medication Safety”:
1. Freemantle N. Does the UK National Health Service need a fourth hurdle for
pharmaceutical reimbursement to encourage the more efficient prescribing of
pharmaceutical? Health Policy 1999; 46: 255-65
2. Lazarou J, Pomeranz BH, Corey PN: Incidence of adverse drug reactions in
hospitalised patient: a meta-analysis of prospective studies JAMA 1998; 279:
1200-5
3. Pirmohamed M et al Adverse drug reactions as cause of admission to hospital:
prospective analysis of 18,820 patients BMJ 2004; 329: 15-19
4. WHO Essential Drugs and Medicines Policy. Available at
www.who.int/medicines
5. Council Directive of 31 March 1992 Concerning the classification for the
supply of medicinal products for human use 92/26/EEC
6. SI 540 of 2003: Medicinal products (Prescription and Control of Supply)
Regulations. Available at www.dohc.ie
7. Misuse of Drugs Regulations (1988, 1993). Available at
www.irishstatutebook.ie
8. Chapter 3 (Glossary) of: EU pharmacovigilance Rules for Human and
Veterinary Medicinal Products. Eudralex Volume 9 – Pharmacovigilance.
Available at www.pharmacos.eudra.org
9. NMIC bulletin on Adverse Drug Reactions 2002; 8(3) 1-4
10. Leape L Error in medicine JAMA 1994; 272: 1851-7
11. NMIC bulletin on Medication Errors 2001; 7(3) 1-4
12. Weingart S et al. Epidemiology of medical error. BMJ 2000; 320:774-7
13. Cunney A et al Prescription monitoring in an Irish hospital. Ir Med J 2003;
96(1) 20-3
14. Summaries of Product Characteristics available on www.medicines.ie
15. BHS guidelines for HTN management 2004: summary BMJ 2004; 328: 63440 with accompanying editorial
16. Building Healthier Hearts: The Report of the Cardiovascular Health Strategy
Group. Publishers: The Stationery Office, Government Publications, Dublin
1999.
17. Barber N et al. Patients’ problems with new medication for chronic conditions.
Qual Saf Health Care 2004; 13: 172-5
18. Campbell w et al. Improving communication of drug risks to prevent patient
injury: proceedings of a workshop. Pharmacoepi and Drug Saf 2003; 12: 183194
19. Smith J., Building a safer NHS for patients: Improving Medication Safety.
Dept of Health (UK). Published Jan 2004. Available at
www.dh.gov.uk/publications