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Andrew Dickman is a hospital pharmacist in Merseyside
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In palliative care, both in hospitals and in the community, pain management
relies heavily on the careful prescribing of a
variety of strong opioid analgesics, such as buprenorphine, fentanyl
and morphine
sulphate. When these agents are prescribed
for self-administration or administration
by carers, the analgesic
prescribed is usually a sustained release oral formulation or a transdermal
product. Accurate and carefully titrated administration of these agents
often results in significant reduction in pain and a better quality of
life for patients who are
terminally ill.
It is a matter for concern that the dispensing of these strong analgesics
is not
always as straightforward and error-proof as one would like. I have
witnessed the potential for confusion from generic prescribing of some
strong opioids. Branded prescribing could greatly reduce that confusion,
but there is currently no requirement for health professionals to prescribe
modified-release Controlled Drugs by brand name.
For Schedule 2 Controlled Drugs, the legal requirements simply state
that prescriptions are written in the prescriber’s handwriting,
signed and dated, with the dose, form and strength of the preparation
specified. In practice, this means it is perfectly acceptable to write
a prescription for “morphine sulphate s/r capsules”. Given
that there is more than one preparation that could be dispensed from
such a prescription, and that the drug
concerned is a Controlled Drug, it seems surprising that such scope for
confusion or
misunderstanding should be allowed. It is
particularly surprising that there has been no tightening up of this
practice in the light of the current post-Shipman environment.
Generic prescribing is widely accepted by health care professionals as
best practice. This is undoubtedly the case for most drugs, both in terms
of cost and safety. It is judicious, in most cases, for prescribers to
use generic names rather than brands, if all the products are equivalent
and interchangeable. However, branded prescribing in some cases can be
both safer and more cost-effective — safer because the potential
for dispensing or
administration confusion is reduced and more cost-effective because,
by minimising the chances of errors occurring, considerable
savings can be made in terms of health professional time, cost of wasted
incorrect medicines and cost of issuing new prescriptions for the correct
product. This assessment does not take into account the potential costs
of rectifying prescribing or dispensing errors that lead to patient harm
or even death.
Exceptions to the generic prescribing rule are currently made for some
products available in modified-release form, such as diltiazem. Equally,
I would suggest there should be a requirement that all modified-release
strong opioids are prescribed in brand form. This is in line with the
report by the Chief Pharmaceutical Officer for England, “Building
a safer NHS for patients”, in which it is suggested that oral sustained-release
opioids should be prescribed by brand name to avoid any possible ambiguity.
Special care needs to be taken with opioid analgesics, given their narrow
therapeutic margin and the variety of doses and formulations available.
There are many potential causes of
prescribing and dispensing errors including dose calculation mistakes,
drug name confusion, use of abbreviations, and availability of different
formulations. Using brand names for those opioid analgesics that pose
a particular risk (modified-release and transdermal products being two
obvious ones) is an eminently useful way to help limit potential damage.
There are various brands of modified-release morphine and two formulations
of both transdermal fentanyl and buprenorphine available for dispensing.
Further strong opioid products
are in the pipeline. Consider transdermal fentanyl. Two formulations
are
currently available, a matrix and a reservoir patch, and there are at
least three different brands of fentanyl patch available to the dispensing
pharmacist. Although it can be
argued that the different formulations are bioequivalent, there are still
significant potential problems if patients used to one type of patch
are dispensed the other type without due explanation (see Panel).
Panel: Case study
Brian, aged 74 years, has advanced lung cancer. He lives at home
and is cared for by his wife. He has an oxygen cylinder by his
bed and receives regular visits from his palliative care nurse.
Brian has been using fentanyl 75µg patches. He has found that
by using one whole patch and cutting another patch in half, he
receives
optimum pain relief, and has been doing this for the past four
months on the advice of his palliative care nurse.
Following the last visit from the nurse, Brian’s wife went
to their local pharmacy to collect his prescription for more fentanyl
patches. The prescription was for “fentanyl TDS 75µg”.
When Brian’s wife got home she found that the patches looked
different from the ones they were normally given at the pharmacy.
When she tried to cut one of the patches in half, she found that
it started to leak.
Brian’s wife decided to use just one 75µg patch and to ask
the nurse for advice when she next called. However, the following
day, Brian complained of increased pain, which became worse. When
the nurse visited Brian, she explained that the patches they had
been given were reservoir patches that could not be cut. Brian’s
wife asked if it was possible to ensure they always got the matrix
type of patches. |
This case study has been adapted from real examples
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Medication errors are all too common in the NHS and their impact on
patient well-being and health costs can be considerable. Deaths attributed
to
medication errors and drug side effects seem to be on the rise in the
UK, and the Audit Commission estimates the cost of this at around £500
million each year due to increased hospital stays. Often, the pharmacist’s
role is limited to retrospective checking and monitoring of prescriptions
but there is a strong argument for the pharmacological expertise of pharmacists
to be used to help reduce the potential for confusion in drug prescribing.
This scenario is becoming increasingly likely now that supplementary
prescribing by pharmacists is a reality.
The present lack of firm guidelines and the consequent scope for confusion
is unsatisfactory. It is all the more worrying given the types of drugs
involved (strong opioids) and the types of patients we are dealing with
(eg, those who are vulnerable, terminally ill and in pain or distress,
or both).
Good clinical practice would suggest that we all strive, as health care
professionals, to make the treatment pathways for these
patients as smooth as possible, with minimal margin for error or confusion.
The likelihood of achieving this goal could be greatly increased if pharmacists
promoted and encouraged the use of branded prescribing for all modified
release and transdermal strong opioids. |
The
Pharmaceutical Journal