Transcript Herbal Remedies and Anaesthesia

Herbal Remedies
and Anaesthesia
Adrian WONG
Specialist Registrar Anaesthetics/ITU
Wessex Deanery
Contents
• Background
• Extent of use
• Issues
• Efficacy
• Regulations
• Common herbal medicines
• Effects on anaesthesia
• Guidelines
Declaration of Interest
Foxglove (Digitalis purpurea)
Periwinkle
Purported use of herbal
remedies
Cancer
Inflammatory Bowel
Disease
HIV/AIDS
Asthma
Eczema
Lack of energy
Arthritis
Obesity
Impotence
Psoariasis
Glands
Depression
Insomnia
Extent of Use
•
UK
•
4.8% of patient use
•
annual expenditure - £1.6 billion
•
America
•
12% general surgical
•
55% cosmetic surgery
•
$27 billion
•
Europe
•
40% of breast cancer patients
•
20% of lung cancer patients
•
World Health Organisation
•
80% of world population
The Issues
• Herbal medicines are ‘safe’
• Natural does not equal safe
• Herbal does not equal benign
• 40% of population - “safe” (MORI 2008)
• Lack of disclosure/enquiry
• Efficacy and evidence-based practice
National Institute of Medical
Herbalists
The Issues
• Herbal medicines are ‘safe’
• Natural does not equal safe
• Herbal does not equal benign
• 40% of population - “safe” (MORI 2008)
• Lack of disclosure/enquiry
• Efficacy and evidence-based practice
• Funding/Product regulation
regulation and licensing of
herbal products
regulation and licensing of
herbal products
• Lack of international consensus
• Herbal products marketed as food supplements
or cosmetics
• Medicine Act 1968
• Exemption from statutory control
• EU Medicines Directive 1994
• Traditional Herbal Medicinal Products Directive
(THMPD) 2004
UK legislation
• Unlicensed herbal remedies
•
Supplied to individual after face to face consultation
• Registered traditional herbal medicine (2005)
•
Specific standards of safety and quality
•
“Agreed indication based on traditional use”
• Licenced Herbal Remedies
"When seeking a licence for herbal medicines, many companies
have had difficulty meeting conventional requirements to
prove efficacy. This was one factor that led to the introduction
of the Traditional Herbal Registration Scheme and many
products are likely to follow that regulatory route."
MHRA - Safeguarding public
health report
• 70 suspected adverse drug reports relating
to herbal remedies
• Handful of identified UK deaths
• Steady flow of cases entailing very serious
illness e.g. kidney or liver failure
• BUT increasing study and scientific
understanding of herbal medicines would
be expected to improve safety profile
BAD MEDICINE - More cases of adverse side effects (The
Singapore Straits Times, 11 October 2011)
Anaesthetic Concerns
“There are known knowns. These are things we know
that we know. There are known unknowns. That is to
say, there are things that we know we don't know. But
there are also unknown unknowns. There are things
we don't know we don't know.”
Anaesthetic concerns
• Unknown effects of herbal remedies
• Potential interactions with drugs
• Pre-operative
• Intra-operative
• Post-operative
• Effects on patient physiology
most common herbal
medicines in the UK
•
Echinacea
•
Ginger
•
St Johns Wort
•
Garlic
•
Saw palmetto
•
Ephedra
•
Ginseng
•
Gingko
•
Valerian
•
Kava Kava
Echinacea (Echinacea
Pururrea)
• Uses
• Common cold
• Wounds/Burns
• UTI
• URTI
• Possible side effects/interactions
• Hepatotoxicity
• Decrease efficacy of corticosteroids
St Johns Wort (Hypericum
perforatum)
•
•
Uses
•
Depression
•
Anxiety
Possible side effects/interaction
•
Induction of P450 3A4
•
Serotonin syndrome
•
Decrease efficacy of anti-HIV drugs
•
Prolong effect of anaesthesia
•
Organ rejection due to reduce
immunosurpressants
Ephedra (Ephedra Sinica)
• Uses
• Antitussive
• Weight loss supplement
• Possible side effects/interactions
• Arrhythmias
• Enhanced sympathomimetic
• MAOI
• Death
Garlic (Allium sativum)
• Uses
• Lipid lowering
• Blood pressure control
• Antiplatelet/Antithrombotic
• Antioxidants
• Possible side effects/interactions
• Potent inhibitor of thromboxane synthetase
• Increased bleeding time
• Epidural haematoma
ginseng (panax ginseng)
•
Uses
•
Antioxidants
•
Energy level enhancer
•
Exam success
•
Possible side effects/interactions
•
Ginseng abuse syndrome
•
sleepiness
•
hypertonia
•
oedema
•
Interactions with antipsychotics
•
Antiplatelet properties
•
Increased bleeding
•
Hypoglycaemia
•
CVS instability
Canadian Anesthesiologists' Society
Can I take herbal and dietary supplements?
The use of herbal medicines is common. Herbal medicine is defined as a plant-derived product used for
medicinal and health purposes; commonly used herbal supplements include echinacea, garlic, ginseng,
ginkgo biloba, St John’s wort and valerian.
Herbal medicines can have a variety of effects on surgery and interact with anaesthetic drugs. Ginkgo,
ginseng and garlic all impair blood clotting and promote excessive bleeding. Prolongation of action of
anaesthesia drugs can occur with valerian and St John’s wort. Herbal dietary supplements should be
stopped two weeks prior to surgery.
Fish oil supplements are also popular as a dietary supplement. They have potential in reducing cholesterol
and hence may reduce the risk of heart attack and stroke. They also have anti-inflammatory properties and
may be used to treat arthritis. The Therapeutic Goods Administration says that omega 3, which is found in
fish oil, has no effect on bleeding and can be continued before surgery.
RCoA Patient Information
Leaflet
• "It is important for you to bring a list of:
• "all the pills, medicines, herbal remedies or
supplements you are taking, both prescribed and
those that you have purchased over the counter"
• "If you are taking medicines, you should continue to
take them as usual, unless your anaesthetist or
surgeon has asked you not to. For example, if you
take drugs to stop you getting blood clots
(anticoagulants), aspirin, drugs for diabetes or herbal
remedies, you will need specific instructions."
British association of Day
Surgery (BADS)
british Association of Day
Surgery (BADS)
“Current” UK practice
•
•
McKenzie and Simpson - Survey of AAGBI members (2005)
•
90% - never or seldom asked about herbal medicines
•
65% - thought there could be potential harm
•
75% - perioperative usage of herbal medicine is important
•
“Unequivocally” poor knowledge
Hogg and Foo - Survey of all anaesthetic dept (2010)
•
7.3% have perioperative herbal medicine policy
•
98.3% did not have specific section documenting herbal medicine use
•
15.7% routinely asked about herbal medicine use
•
Highly variable advice given (not in accordance to existing guidelines)
Conclusion
• The use of herbal remedies in patients
undergoing anaesthesia is under-reported.
• Side-effects and herb-drug interactions can be
unknown.
• Elective surgery - all herbal medication should
be stopped for between 2 and 3 weeks prior.
• Emergency surgery - carry on.
• Improved education and knowledge crucial.
References
1. MHRA Public Health Risk with Herbal Medicines: An Overview (2010)
2. Hogg LA and Foo I. Management of patients taking herbal medcines in the perioperative period: a
survey of practice and policies within Anaesthetic Departments in the UK. EJoA 2010; 27: 11-15.
3. American Society of Anesthesiolgist. What You Should Know About Your Patients’ Use of Herbal
Medicines and Other Dietary Supplements (2010).
4. McKenzie AG and Simpson KR. Current management of patients taking herbal medicines: a survey
of anaesthetic practice in the UK. EJoA 2005; 22: 597-602.
5. Cheng B, Hung CT, Chiu W. Herbal medicine and anaesthesia. HKMJ 2002; 8: 123-130.
6. Skinner CM and Rangasami J. Preoperative use of herbal medicines: a patient survey. BJA 2002;
89(5): 792-795.
7. Batra YK and Rajeev S. Effect of common herbal medicines on patients undergoing anaesthesia.
IJoA 2007; 51(3): 184-192.
8. Hodges PJ and Kam PCA. The peri-operative implications of herbal medicines. Anaesthesia 2002;
57: 889-899.
9. Ang-Lee M, Moss J and Yuan CS. Herbal Medicines and Perioperative Care. JAMA 2001; 286: 208216.