MED2042 WEEK 4 - Complimentary medicine (Herbal medicines)
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- What are the most common items taken as complementary and alternative medicines in Australia?
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Vitamins and minerals i the absence of any specific therapeutic indication
Herbal medicines
Traditional Chinese Medicines - What is the use of complementary medicines in Australia?
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- $2.3 billion spent on complementary medicine in 2000 (4x more than public contributions to pharmaceuticals)
- In 2000, >50% of Australians used complementary medicines, and 23% visited a complementary healthcare practitioner.
- > 50% of people using Complementary medicines do not tell their doctor
- Over 80% of people seeking complementary treatment for "serious medical conditions" were also found to be receiving treatment form a medical doctor for the same condition. - List GP's use of some complementary therapies (%).
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Acupuncture
- 90% have referred before.
- 19% have practised.
Meditation
- 80% have referred before.
- 15% have practised.
Hypnosis
- 82% have referred before.
- 9% have practised
Chiropractic
- 69% have referred before.
- 5% have practised.
Herbal medicine
- 30% have referred before.
- 5% have practiced
Naturopathy
- 30% have referred before.
- 3% have practised
Vitamin therapy
- 17% have referred before.
- 25% have practised. - Describe the short history of pharmacy.
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"Pharmacist, I have an ear ache, what can I take?"
2000 BC - "Here, eat this root"
1000 AD - "That root is blasphemy, say this prayer"
1850 "That prayer is superstition, drink this potion"
1930 - "That potion is snake oil, swallow this pill"
1970 - "That pill is ineffective, take this antibiotic"
2000 - "That antibiotic is articicial. Here, eat this root" - Why is there the belief in the safety of herbal medicines?
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- It is common knowlegde that tobacco, opium and deadly nightshade can all cause death
- However many people falsely believe that because herbal medicines are "natural" they must be safe.
- Many plants have evolved potent toxins to prevent being eatn by animals. - What are some adverse effects of complementary medicine?
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Bee products: anaphylaxis
Black Cohosh: Liver impairment
Echinacea: allergic reactions
Ginkgo biloba: interaction with warfarin - bleeding
Guarana: caffeine overdose
St John's wort:
- reduced effect of cyclosporin & oral contraceptives
- sertotonin syndrome with SSRIs or tramadol
- dangerous increase in levles of interacting drugs when stop St John's wort. - What are some adverse effects of high doses of vitamins?
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Vitamin A: birth defects
Vitamin B3 (nicotinic acid): cardiovascular disturbance, itch and rash, gastrointestinal upset, liver dysfunction
Vitamin B6 (pyridoxine): sensory neuropathy
Vitamin C: kidney stones, diarrhoea
Vitamin D: hypercalcemia, muscle weakness, hypertension, headache, heart arrythmias - What does a TGA listing mean?
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TGA listing (AUST L), e.g. herbal medicines:
- considered low risk products (often without much evidence)
- evaluated for quality and safety, manufacturing
- cannot make therapeutic claims
- must abide by labelling requirements - What does a TGA registration mean?
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TGA registration (AUST R), pharmaceuticals:
- evaluated for quality, safety and effectiveness using toxicology, pharmaceutical and clinical data
- cannot make therapeutic claims to the public - What are the problems for standardisation of herbal preparations?
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- Wide range of compounds present in herbs
- plant identification (species) and age
- climate, soil, altitude, sunlight etc
- genetic variation (subspecies etc)
- which part of plant is used
- method and time of harvesting
- handling and storage after harvesting
- extraction and processing
- stability, storage
- formulation, combination - What are the herb sales in USA?
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Echinacea - 10% - for cold etc
St John's wort - 9% - depression
Gingko biloba - 9% - dementia
Garlic - 7% - various
Saw palmetto - 5% - prostatism
Gingseng - 5% - fatigue, others
Golden seal - 4% - gastritis etc
Total - 49% - What is the safety of herbs like?
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- many herbs have been withdrawn from use because of liver or kidney toxicity (e.g. comfrey, Aristolochia-containing preparations)
- many can cause allergic or photosensitivity reactions and interact with pharmaceuticals
- most herbal preparations have not been adquately studied for safety or interactions
- long term effects are often unknown
- effects during pregnancy and childhood are often unknown
- some unregulated complementary medicines (e.g. from internet sources) are adulterated e.g. with steroids or NSAIDs (to enhance activity), lead (a sedative!), mercury or arsenic (anti-bacterial!) - What are the problems with randomised controlled trials and complementary therapies?
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- The few studies done are often small and/or of poor quality
- There is limited funding available (e.g. companies marketing herbal preparations may be reluctant to fund studies that could potentially find their product no better than placebo)
- Many therapies are practiced "holistically"
- There may be difficulties with placebos & blinding
- Difficulties with outcome measures - What are some examples of complementary therapies supported by systematic reviews?
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Acupuncture
- nausea and vomiting
- dental pain
- back pain
Herbalisim
- Saw palmetto: benign prostatic hyperplasia
- St John's wort: mild depression
- Ginkgo biloba: dementia, cerebral insufficiency, intermittent claudication
Chiropractic
- acute back pain
Osteopathy
- Back pain - What are alternative therapies in cancer?
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- There have been more claims for "wonder cures" for cancer than any other ocnidtion
- Alternative remedies such as shark cartilage, laetrile & high dose vitamins have been used with little evidence of efficacy, and sometimes with a worsened outcome
- Deaths have occurred in children whose parents ahve refused conventional therapy in favour of alternative therapies for some treatable cancers
- Many plants have been screened for anticancer avtivity and a few active products have been found which are now in pharmaceutical use, e.g. vinca alkaloids (from the Madagascar Periwinkle), paclitaxel (from the pacific yew tree) - What are alternative therapies for arthritis?
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- Cartilage extracts including glucosamine and chondroitin sulphate are being used
- A meta-analysis of trials of glucosamine and chondoitin does show some effectiveness in short-term studies
- Issues of quality control, adverse effects and long-term benefit need to be addressed - What has Ginkgo biloba been used for?
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- Recently become popular in treatment of alzheimer's dementia.
- Long history of use for circulatory disorders
- A vasodilator and inhibitor of platelet aggregation
- Meta-analysis of clinical trials has shown benefit in treating claudication (pain in claves on exercise usually due to atherosclerosis in blood vessels)
- 9 randomised clinical trials (~1500 patients) showed benefit in dementia
- can cause bleeding - What evidence has been found for St John's wort?
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- One meta-analysis of 23 trials (~1700 patients) and a sytematic review of 8 "strong" trials (~1000 patients) have concluded that St John's Wort is effective for mild to moderate depression
- May not be effective for sever depression
- Can be expensive
- Many potential drug interactions (some serious) - What evidence has been found for Saw Palmetto?
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- American dwarf palm
- Systematic review of 18 randomised trials (~3000 patients) showed effectiveness in short-term treatment of benign prostatic hypertrophy
- helps to increase urine flow - What evidence has been found for Kava?
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- used as a sedative and anxiolytic, e.g. by some Pacific islanders
- Effects fairly short-lived
- can cause liver damage - What evidence has been found for ginger?
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A few trials have shown effectiveness in treatment of nausea and vomiting due to pregnancy.
Ginger is possibly mutaenic in high doses in bacteria, and safety in humans in therapeutic doeses is not completely established
A meta-analysis of clinical trials stated that "ginger should be applied for the time being only in controlled clinical studies" - What evidence has been found for Cranberry juice?
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- Cranberry juice has been found to lower the incidence of bacterial urinary tract infections
- It may prevent bacteria from adhering to the bladder epithelium
- However, a Cochrane Review shoed no benefit in prevention of urinary tract infections - Give a summary of herbal medicine.
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- For some alternative therapies, there is scientific evidence for effectiveness
- However, for most, there is no good quality scientific evidence of effectiveness and little data on safety
- Private health insurance schemes provide rebates for many alternative therapies, on the bais of demand rather than evidence of effectiveness
- for many conventional therapeutic practices there is also a lack of scientific evidence for effectiveness
- consumers will choose alternative therapies whether there is scientific evidence or not - Define anxiolytic.
- Anxiety relieving.