Transcript Herbal Medicine - SWONS: Home Page

Herbal Medicine
Penny Franklin
MA Complementary Health Studies
Senior Lecturer Non medical prescribing
University of Plymouth
May 2005
Intended presentation outcomes
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Discuss the significance of Complementary
and alternative medicine for conventional
prescribing
Highlight the difficulties involved in obtaining
reliable information on this topic
Discuss significant drug interactions and
cautions that relate to different patient groups
History
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Complementary and alternative medicine (CAM)
Herbal medicine at least 5,000 years old
CAM interest grown over past two decades
Over 31 million visits to CAM practitioners 1998
(Thomas et al, 2001)
One in five Britons seeks complementary or
alternative therapy.
Perceived to be ‘safe’
Research lagging behind
Health care professionals are thought to know
What is CAM?
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Complementary and alternative medicine. The
treatment of disease using methods other than
recognised/conventional medicine.
Use of homeopathic, herbal, aromatherapy and
over the counter vitamin supplements to treat
conditions
Often not adequately clinically trialled
Might not have a product licence
Homeopathic and Herbal medicine
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Homeopathy: Homeos (Similar) Pathos (disease)
Like cures like – remedy mimics symptoms
The greater the dilution – the greater the therapeutic effect
(serial dilution)- hardly any or no trace of active ingredient
Manufacture controlled by Medicines Act 1968
Medical claims cannot be made for remedies
However, leaflets can be displayed nearby
Medical homeopaths (medically qualified and regulated by
GMC)
Non Medical homeopaths (regulated by different
bodies/Fellowship of homeopaths etc
Effects on patients
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Limited evidence with regard to adverse drug
reactions
Little evidence with regards to drug
interactions
Herbalism
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National Institute of Medical Herbalists 1864
(professional body)
Phytotherapy-the science of herbalism
Herbal medicines
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Plant derived medicines at pharmacological
doses where effects can be measured
Symptom based approach to diagnosis
Commonly used herbal medicines
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Glucosamine (not strictly herbal)- For relief of
joint pain (side effects:mild GI symptoms,
rash, drowsiness, headache and insomnia
May alter glucose sensitivity
Caution if pregnant or breastfeeding or if
allergic to shell fish
Saw Palmetto
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Urogenital conditions – Benign prostatic
hyperplasia
Side effects: - dizziness, and GI disturbance
Rare,- mild puritis, headache and hypertension
? Erectile dysfuntion (similar to placebo)
Drug interactions ? Hormonal therapies
(Contraception and HRT)
Cautions: Pregnancy and breastfeeding, sex
hormone dependent cancers
Valerian
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Insomnia
Side effects: headache, drowsiness, (sedation) GI
symptoms, rarely nervousness and excitability
? Cardiac disturbances rarely on sudden withdrawal
(not confirmed)
Precautions: Pregnancy and breastfeeding, before
driving or operating heavy machinery,
Not to be taken if known hypersensitivity
Can cause dependency
St John’s Wort
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Mild depression –
Caution (Liver enzyme inducer (antiepileptics)( theophylline )(the Pill) (SSRI’s), (
wafarin)
Echinacea
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Prevention of upper respiratory tract infections
Side effects: Nausea, dizziness, shortness of breath, burning
and numbing sensation on tongue, dermatitis, hepatitis, puritus
and hepatoxicity
Drug interactions: Other hepatotoxic drugs e.g anabolic
steroids, amiodarone, ketoconazole and methotrexate also
immunosuppressants (might decrease effect)
Cautions: asthma, atopy or allergy, hypersensitivity to
sunflowers, liver dysfunction, TB, diabetes, HIV, MS, SLE
and other autoimmune diseases
Pregnancy and breastfeeding
Do not take continuously for more than eight weeks
Regulation of herbal medicines
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Licensed: Marketing authorisation (product
license) issued by Medicines and Health Care
products Regulatory Agency (MHRA)
Have to meet safety, quality and efficacy
standards similar to conventional drugs
Unlicensed: Exempt from licensing
requirements (Section 12 of Medicines act
1968)
Section 12 Medicines Act 1968
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Section 12 (1) person can make, sell and supply herbal remedy
as part of business provided remedy is manufactured on the
premesis and supplied as the consequence of a consultation
between patient and herbalist
12(2) allows manufacture and supply where
Process of manufacture consists of drying, crushing or
comminuting
Remedy sold without any written recommendation as to its use
Remedy sold under a designation which only specifies the
plant and the process and does not apply any other name to the
remedy
Statutory regulation
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Moves afoot to regulate industry
House of Lords Select Committee
2000
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Tougher regulation
More rigorous testing
Greater supervision of practice
Only those with a statutory regulation or
powerful self regulation should be available on
NHS
Only by referral from GP.
Safety and
Regulation.
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“We are concerned about the safety
implications of an unregulated herbal sector
and we urge that all legislative avenues be
explored to ensure better control of this
unregulated sector in the interests of public
health.”
Safety
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Lack of data
‘Natural’ does not always mean safe e.g
digitalis
Kava Kava hepatotoxicity
Safety Issues
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Remember herbal remedies are medicines
Report adverse reactions to doctor or
pharmacist
May interact with other medicines
Natural does not mean safe
Duty of Care when prescribing
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To facilitate full and informed consent
To do no harm
Negligence – Proven breach of duty of care
and harm to patient
When prescribing
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Always ask the patient what else they are
taking
Including Over the Counter medication and
herbal medicines
Consider potential drug interactions
BNF (2005) and Stockley (2002)
Alert
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Patients taking drugs with a narrow theraputic
index e.g wafarin or a drug therapy which is
considered critical ( e.g insulin) should avoid
using complementary medicines
Women who are pregnant or breastfeeding
should avoid complementary medicines
Problems
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Poor manufacturing process
Adulteration to include toxic substances and
conventional drugs
Misidentification of herbs
Substitution of herbs
Varying strengths of preparations
Incomplete labelling
Incorrect dosage and instructions
Reporting
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To the MHRA using yellow card reporting
Important for all drugs especially those less
well known.
References
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http://www.mcs.gov.uk/ourwork/licensingmeds/herbalsafety
Stockley IH (2002) Drug interactions. 6th edition. London:
Pharmaceutical Press; 2002
Thomas, K et al., Use and expenditure on complementary
therapies in England: a population based survey.
Complementary Therapies in Medicine 2001; 9(1): 2-11
Zollman C, Vickers A. ABC of complementary medicine:
what is complementary medicine? BMJ 1999; 319: 693-696
UKMI Complementary Medicines Summaries December 2002