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Alison Blenkinsopp is professor of the practice
of pharmacy at the department of medicines management, Keele University
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St John’s wort poses a dilemma to community pharmacists in their
everyday practice. It is a dilemma for several reasons: it is not a licensed
medicine; there is a debate about its clinical effectiveness and about
which constituent might be responsible for any clinical effect; there
is evidence of risk from interactions with other medicines; and there
are issues about pharmaceutical quality of products containing St John’s
wort, so that obtaining dose accuracy and consistency is difficult. Finally,
but importantly, if there is evidence of clinical effectiveness for St
John’s wort, should a pharmacist attempt to “diagnose” depression,
or to confirm a customer’s self-diagnosis? Or is the treatment
of depression something which only doctors should advise on? Despite
all of this St John’s wort has a powerful lay reputation as a “natural” alternative
to “chemical” antidepressants.
Requests for St John’s wort
So how, when faced with a request relating to St John’s wort, should
a community pharmacist react? Should a community pharmacist even be stocking
St John’s wort given the issues surrounding it?
Pharmacists or medicines counter assistants might be asked for St John’s
wort by name, for an opinion on its effectiveness, or about whether they
would recommend it for depression. Research has shown that pharmacists
are indeed asked about all of these.1 The research findings indicate
that pharmacists’ attitudes towards, and their knowledge about,
potential therapeutic benefits and risks from St John’s wort are
variable. Pharmacists showed awareness of the symptoms and signs of depression
and how these differed in severe depression.
A Consumers’ Association study criticised the advice given by five
of 21 pharmacists about St John’s wort and potential interaction
with the combined oral contraceptive pill. Although the design of the
scenario used has been criticised the study nevertheless raised issues
about consistency of approach and advice about St John’s wort.
Pharmacists have an ethical responsibility for currency of knowledge
about any medicines that they offer for sale or supply to the public.
As BNF No 28 points out: “St John’s wort (Hypericum perforatum)
is a popular herbal remedy for treating mild depression. However, preparations
of St John’s wort can induce drug metabolising enzymes and a number
of important interactions with conventional drugs have been identified,
see Appendix 1 (St John’s wort). The amount of active ingredient
can vary between different preparations of St John’s wort and switching
from one to another can change the degree of enzyme induction. Furthermore,
when a patient stops taking St John’s wort, concentrations of interacting
drugs may increase, leading to toxicity. Antidepressants should not be
used with St John’s wort because of the potential for interaction.”
Thus the BNF highlights the safety issues and directs readers to its
section on interactions. A Royal Pharmaceutical Society factsheet for
pharmacists on St John’s wort also summarises safety issues and
makes suggestions about appropriate questions to ask people who request
St John’s wort.
A Cochrane review of St John’s wort states: “There is evidence
that extracts of hypericum are more effective than placebo for the short-term
treatment of mild to moderately severe depressive disorders. The current
evidence is inadequate to establish whether hypericum is as effective
as other antidepressants.”
Finding authoritative information about active constituents and appropriate
doses is more challenging. The PRODIGY guideline on depression summarises
the evidence, safety and pharmaceutical quality issues but does not comment
on dosage. Furthermore there remains the issue about how a pharmacist
would differentiate between mild to moderate depression (for which evidence
indicates St John’s wort may help) and severe depression (for which
the evidence is clear that St John’s wort does not help). Suggesting
that a person might consult their GP is one option but some people do
not want to seek medical advice, particularly for mild depression. Ethical obligations
So can community pharmacists fulfil their ethical obligations in relation
to advice on, and sales of, St John’s wort? A possible framework
for considering a policy on St John’s wort for your pharmacy
might be:
· Am I prepared and competent to advise on St John’s wort?
· Is it appropriate for my medicines counter assistants to deal with
St John’s wort requests? (If yes, are they prepared and competent
to do so?)
· Does my pharmacy’s process for dealing with St John’s wort
systematically minimise risk to individuals who purchase it?
· Can I (and my staff) recognise severe depression to provide a basis
for referral?
More fundamental questions when considering whether to stock and supply
certain products might be:
· If I do not know, or do not believe, that this product works, should
I stock it?
· How should I respond to individuals who ask for my opinion about whether
this product works or whether it is worth purchasing?
· Are there any ethical conflicts in stocking this product?
· Is it ethical to sell a product in response to a request but not be
prepared to advise on the use of that product?
It could be argued that if community pharmacies do not stock and advise
on St John’s wort the potential risks to the public would be increased.
Unlike pharmacies, health food shops are not subject to requirements
of training or ethics and their advice is unregulated. There is no British
research on the quality of advice about St John’s wort from staff
in health food shops but a US study2 concluded: “Their comments
could cause significant harm to customers.” The internet is a key
vehicle for the supply of St John’s wort and the quality of information
supplied is unknown. As the “experts on medicines” and public
health advocates on the high street, should pharmacists not be ready
to provide decision support and help the public navigate a path through
areas where the evidence is not clear and definitive? Barnes suggests: “Pharmacists
are well placed to advise patients on the safe, effective and appropriate
use of St John’s wort and other herbal products, and to assist
patients in selecting products of suitable quality.”3 Or is it
unacceptable to use risk minimisation as a reason for doing things that
are less than ideal?
Pharmacists also need to think about how they might be judged if things
go wrong or a complaint is made, not just in relation to St John’s
wort but to any medicine sold to the public. It would be important for
a pharmacist to be able to show that a decision-making process had been
undertaken rather than a sale by default, and for that process to be
transparent. It would also be important to show
that they had assessed the possible risks and formulated appropriate
responses to customer requests, and ensured staff were familiar with
these. These are the principles of clinical governance as applied to
over-the-counter medicine sales. How does your pharmacy measure up?
Acknowledgement I am grateful to Michelle King (see p302), Kristian
Pollock, Janet Grime and Zuzana Deans for discussions about issues and
concepts raised here.
References
1. Landers M, Blenkinsopp A, Pollock K, Grime J. Community pharmacists
and depression: the pharmacist as
intermediary between patient and physician. International Journal of
Pharmacy Practice 2002;10:253–65.
2. Glisson JK, Rogers HE, Abourashed EA, Ogletree R, Hufford CD, Khan
I. Clinic at the health food store? Employee
recommendations and product analysis. Pharmacotherapy 2003;23:64–72.
3. Barnes J. St John’s wort is hypericum (letter). The Pharmaceutical
Journal 2001;266:538. |
The
Pharmaceutical Journal