Transcript Document

Herbal Medicines and Women's
Health
British Pharmaceutical
Conference 2005
Elizabeth M Williamson
Scope of talk
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General overview of the most important herbs
used by women (excluding those covered
earlier in more detail), where available for selfmedication or to purchase OTC
Assessment of evidence available
Any problems reported or anticipated when
taken with conventional drugs
Issues of particular importance to women
– and not always for health reasons!
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Hormonal: premenstrual syndrome (PMS),
dysmenorrhoea, menorrhagia
Menopausal symptoms, including osteoporosis
Child-birth, pregnancy and lactation
Life-style: stress, memory loss (which may be
linked with hormonal changes)
Appearance: weight-loss, cosmetic issues (again
linked to causes above)
Herbs used in hormonal conditions
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PMS: evening primrose oil, St John’s wort,
agnus castus
Dysmenorrhoea: dong quai, raspberry leaf,
cramp bark
Menorrhagia (refer to GP or specialist): agnus
castus, horsetail etc. Check iron levels.
Menopause: phytoestrogens, black cohosh,
agnus castus, dong quai, St John’s wort (for
depression), sage (for flushing and sweating)
Herbs and products: for PMS,
menorrhagia and menopause
Herbs used during pregnancy and
lactation
Pregnancy; for morning sickness: ginger*
 Late pregnancy; to prepare for child-birth:
raspberry leaf*
 Lactation; to enhance: shatavari (wild
asparagus*), agnus castus, fennel,
fenugreek
 Lactation; to suppress: sage, peppermint
*will be further discussed
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Herbs and products:
pregnancy and lactation
Herbs used to treat varicose veins
To increase venous tone and strengthen
blood vessels: horse-chestnut*, butcher’s
broom*
 To promote blood flow: red vine leaf*,
bilberry, ginkgo, yarrow and hawthorn
 To soothe itching: topically applied
calendula, witch hazel etc
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Herbs and products:
varicose veins
Herbs used to slow memory loss!
 General
memory and cognition
enhancement: sage*, lemon balm*,
ginkgo*
 Shown to help in post-menopausal
memory problems: soya*, ginseng*,
ginkgo*
Herbs and products: memory and
cognition
Life-style issues: weight loss
traditionally used – no
mechanism of action postulated
 Kelp: to ‘speed up’ metabolism and
provide nutrients (e.g. iodine)
 Ephedra*: for appetite suppression
and to speed up metabolism
 ‘Detox’ mixtures
 Boldo:
Herbs and products: ‘helping’ with
weight loss
Herbs ‘suitable’ for self-medication?
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Women usually look after the health needs of
the family
Many herbal products are purchased OTC, as
opposed to consulting a general practitioner,
pharmacist or medical herbalist
Pharmacist ideally placed to advise…
…..if they know about herbal medicines!
NB: medical herbalists use many more on an
individual basis
A closer look at some of these
 Some
work!
 Some don’t!
 ….and some are dangerous….
Pregnancy: ginger (Zingiber
officinalis) for morning sickness?
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Contains: gingerols and shogaols (phenolics)
Evidence for efficacy? Yes, but limited.
Safe? Current thinking is that up to 5 days can
be recommended, and doses limited (1-2g
daily, in divided doses)
Concerns about possible mutagenicity, but no
clinical evidence in support
Some authorities suggest only up to normal
food levels (approx 1g daily)
Childbirth – is Raspberry leaf
(Rubus idaeus) useful?
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Contains: flavonoids, unknown actives
Raspberry leaf widely available
Evidence for efficacy? Very limited – conflicting
reports from 2 Australian studies
But how do you measure it?!
Pharmacological studies show weak uterotonic
effect
Safety???
Herbs used in lactation
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No clinical evidence for any, but traditional
usage by herbalists widespread for all
For shatavari (Asparagus racemosus) some
pharmacological studies in rats and er…
buffaloes - showed increase in milk flow
Remember constituents may pass into breast
milk
Varicose veins and ‘heavy legs’:
saponin-containing herbs
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Horse Chestnut (Aesculus hippocastanum) and
Butcher’s Broom (Ruscus aculeatus), both used
internally and externally
Evidence: good! (Internal use in pregnancy not
recommended due to absence of research, but a
small study of horse-chestnut reported no
adverse events after 2 weeks)
Safety: no clinical reports of toxicity
Varicose veins: flavonoid and
anthocyanin-containing herbs
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Red Vine (Vitis vinifera)– leaf extract, both internally
and externally. Contains flavonoids and anthocyanins.
Evidence: reasonable –several clinical studies to
support
Bilberry, hawthorn, ginkgo: little evidence in varicose
veins, but some rationale for use
Safety: no reports as yet of interactions
Internal use in pregnancy not recommended due to
absence of research
Memory enhancement
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Evidence available for ginkgo (Ginkgo biloba),
soya (Glycine max), ginseng (Panax ginseng)
in menopausal women – but the extent of their
usefulness is not yet established
May be related to various types of activity –
e.g. oestrogenicity, increase in cerebral blood
flow, stimulant effects etc
Weight loss
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No clinical evidence for any, except ephedra,
(Ephedra sinica, Ma Huang)
Contains ephedrine, a sympathomimetic
(amphetamine-like) biogenic amine
Banned in the US
Responsible for some deaths
Detox mixtures usually diuretic herbs with extra
nutrients or minerals
Relevant herb-drug interactions 1
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Agnus castus: theoretical possibility of interacting with
dopaminergic receptors
Bilberry – none reported, none expected
Boldo: report (unproven) of interaction with warfarin
Butcher’s Broom: none reported
Dong quai: 1 case with warfarin (reduced prothrombin
time)
Evening Primrose oil: inhibits CYP3A4, 1A2, 2C9, 2D6
and 2C19 in vitro – however, similar fatty acids are
common in many foods
Ginger: inhibits CYP3A4, 1A2, 2C9 and 2D9 in vitro –
but no clinical reports
Relevant herb-drug interactions 2
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Ginseng: conflicting reports on CYP enzymes; weak
inhibition of P-glycoprotein; avoid with MAOIs, warfarin,
nifedipine and cancer chemotherapy
Horse chestnut: none reported
Raspberry leaf: none reported
Red Vine: none reported
St John’s wort: oral contraceptives,
Sage: none reported
Soya: conflicting reports, but avoid with oestrogens
and anti-oestrogens for obvious reasons
Conclusions
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Women are very likely to take herbal medicines
Only a few are well researched (see previous
presentations)
Some are effective, some not
Most appear to be safe
The interaction profile of most is favourable –
although St John’s wort has the usual caveats
Unfortunately slimming herbs don’t work!
Reference sources
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Principles and practice of Phytotherapy. Mills S and Bone K,
Churchill Livingstone, UK, 2000
Potter's Cyclopedia of Herbal Medicines, E M Williamson, C W
Daniels, UK. 2003
Interactions between Herbal and Conventional Medicines. E M
Williamson (2005) Expert Opinion in Drug Safety 4 (2) 355-378
Major Herbs of Ayurveda. Dabur Research Foundation. Ed: E M
Williamson; Elsevier 2002
Herbal Medicines 2nd Edition. Barnes, Anderson and Phillipson.
Pharmaceutical Press 2002
Natural Standard Herb and Supplement Reference.
Evidence-Based Clinical Reviews. Mosby 2005