Clinical review

Homoeopathy

Andrew Vickers,  Catherine Zollman. 

	Background

Top Background How can homoeopathy work? What happens during a... Therapeutic scope Safety of homoeopathy Practitioners

Homoeopaths treat disease using very low dose preparations administered according to the principle that "like should be cured with like." Practitioners select a drug that would, if given to a healthy volunteer, cause the presenting symptoms of the patient. For example, the homoeopathic remedy Allium cepa is derived from the common onion. Contact with raw onions typically causes lacrimation, stinging and irritation around the eyes and nose, and clear nasal discharge. Allium cepa might be prescribed to patients with hay fever, especially if both nose and eyes are affected.

Samuel Hahnemann (1755-1843), the German physician who first described homoeopathy, began his pioneering experiments in the 1790s

Other common homoeopathic medicines include those made from plants such as belladonna, arnica, and chamomile; minerals such as mercury and sulphur; animal products such as sepia (squid ink) and lachesis (snake venom); and, more rarely, biochemical substances such as histamine or human growth factor. The remedies are prepared by a process of serial dilution and succussion (vigorous shaking). The more times this process of dilution and succussion is performed, the greater the "potency" of the remedy.

Homoeopathic medicines are made from various materials, including animal products such as sepia from squid ink

Prescribing strategies in homoeopathy vary considerably. In what is often termed "classical" homoeopathy, practitioners attempt to identify the single medicine that corresponds to a patient's general "constitution"a complex picture incorporating current illness, medical history, personality, and behaviour. Two patients with identical conventional diagnoses may receive very different homoeopathic medicines.

Other practitioners prescribe combinations of medicines ("complex homoeopathy") or prescribe on the basis of conventional diagnosis alone. There is currently insufficient evidence concerning the relative benefits of the different approaches to treatment.

The complex lattice formations created by water molecules are thought by some to hold the key to understanding the mechanism by which homoeopathy might work

	How can homoeopathy work?

Top Background How can homoeopathy work? What happens during a... Therapeutic scope Safety of homoeopathy Practitioners

It is well known that many homoeopathic medicines are ultramolecularthat is, they are diluted to such a degree that not even a single molecule of the original solute is likely to be present. As drug actions are conventionally understood in biochemical terms, homoeopathy presents an enormous intellectual challenge, if not a complete impasse. Many scientists have suggested that the clinical effects of homoeopathic medicines are solely due to the placebo effect. However, there have been rigorous, replicated, double blind, randomised trials showing significant differences between homoeopathic and placebo tablets.

The response to this has been mixed. Some people remain unconvinced by the evidence, claiming that there must be another explanation, such as methodological bias, for the results. Others point out that the evidence is very strong and argue that homoeopathic medicines must work by some, as yet undefined, biophysical mechanism. One possible explanation, currently being investigated, is that during serial dilution the complex interactions between the solvent (water) molecules are permanently altered to retain a "memory" of the original solute material.

	What happens during a treatment?

Top Background How can homoeopathy work? What happens during a... Therapeutic scope Safety of homoeopathy Practitioners

Homoeopaths' consultations for chronic conditions include an extremely detailed case history. Patients are asked to describe their medical history and current symptoms. Particular attention is paid to the "modalities" of presenting symptomsthat is, whether they change according to the weather, time of day, season, and so on. Information is also gathered about mood and behaviour, likes and dislikes, responses to stress, personality, and reactions to food. The overall aim of the history taking is to build up a "symptom picture" of the patient. This is matched with a "drug picture" described in the homoeopathic Materia medica. On this basis, one or more homoeopathic medicines are prescribed, usually in pill form. Sometimes treatment consists of only one or two doses. In other cases a regular daily dose is used.

Two to six weeks after the start of treatment, progress is reviewed and alterations made to remedy or dilution. A patient's initial symptom picture commonly matches more than one homoeopathic remedy, and follow up allows the practitioner to make an empirical judgment on whether a particular remedy was the correct one to prescribe. If the patient is doing well the practitioner may stop treatment and monitor progress. If symptoms recur the treatment may be repeated at the same or a higher potency. If the symptom picture has changed at follow up a different homoeopathic prescription may be given even though the conventional diagnosis remains unchanged.

Homoeopathic consultations in private practice may last over an hour, although many NHS general practitioners practise basic homoeopathy in 10-15 minute appointments. Many homoeopaths also recommend changes to diet and lifestyle, and some advise against vaccination (see section on safety below).

	Therapeutic scope

Top Background How can homoeopathy work? What happens during a... Therapeutic scope Safety of homoeopathy Practitioners

Most of a typical homoeopath's caseload consists of chronic or recurrent conditions such as eczema, rheumatoid arthritis, fatigue disorders, asthma, migraine, dysmenorrhoea, irritable bowel syndrome, recurrent upper respiratory or urinary tract infections, and mood disorders. Homoeopaths also treat a substantial number of patients with ill defined illness that has not been given a conventional diagnosis. Children are much more commonly treated by homoeopaths than by other types of complementary practitioner.

Some homoeopaths say that few conditions are truly outside their remit, and the homoeopathic case literature includes treatment of complaints as diverse as tuberous sclerosis, infertility, myasthenia gravis, fear of flying, and cystic fibrosis. That said, opinions about what can be effectively treated by homoeopathy differ widely, even among homoeopaths, with medically trained practitioners generally being more conservative than non-medical ones. It is also used, often by self prescription, to treat various acute conditions such as the common cold, bruising, hay fever, and joint sprains.

Research evidence
Given the difficulties in understanding how homoeopathy may work, researchers have concentrated on establishing whether it is a placebo treatment. Current evidence suggests that this is probably not the case. A recent meta-analysis, published in the Lancet, examined over 100 randomised, placebo controlled trials and found an odds ratio of 2.45 (95% confidence interval 2.05 to 2.93) in favour of homoeopathy. The authors concluded that, even allowing for publication bias, "the results of our meta-analysis are not compatible with the hypothesis that the clinical effects of homoeopathy are completely due to placebo."

Laboratory experiments showing effects of homoeopathic medicines on animals provide evidence that the effects of homoeopathy are not entirely due to placebo

Some homoeopaths, mainly those without medical qualifications, believe that vaccination does more harm than good

	Safety of homoeopathy

Top Background How can homoeopathy work? What happens during a... Therapeutic scope Safety of homoeopathy Practitioners

Serious unexpected adverse effects of homoeopathic medicines are rare. "Aggravation reactions," when symptoms become acutely and transiently worse after starting homoeopathic treatment, have been described and are said by homoeopaths to be a good prognostic factor. They may cause concern, especially if patients and doctors are not adequately forewarned.

Pharmacy of Royal London Homoeopathic Hospital. NHS homoeopathic hospitals employ conventionally trained pharmacists, who have additional training in homoeopathy and sometimes herbal medicine. They dispense a range of complementary medicines which are prescribed by medically qualified practitioners

A potentially more serious issue is the belief of some practitioners that conventional drugs reduce the efficacy of homoeopathy. Serious adverse events have resulted from patients failing to comply with essential conventional treatments while using homoeopathy. Some, mainly non-medical, homoeopaths are also strongly against vaccination, although the official policy of the Society of Homoeopaths is to give patients information and choice and not to pressurise against immunisation. Homoeopaths may offer alternatives to vaccination. These have not been subjected to clinical trials and cannot therefore be recommended as an effective substitute.

There have been examples of homoeopathic medicines being adulterated with drugs, although this is extremely unlikely in the case of registered practitioners in Britain.

	Practitioners

Top Background How can homoeopathy work? What happens during a... Therapeutic scope Safety of homoeopathy Practitioners

About 1000 UK doctors practise homoeopathy, although fewer than half of these are full members of the Faculty of Homoeopathy. Many are general practitioners who have received only a basic training and who normally prescribe a limited number of remedies for specific acute conditions. Over 1500 homoeopaths without a conventional healthcare background are thought to practise in the United Kingdom.

Homoeopathy has been part of the NHS since its inception. There are currently five homoeopathic hospitals, of which the two largest, in Glasgow and London, have inpatient units. The hospitals provide a range of conventional and complementary treatments in addition to homoeopathy. Normal NHS conditions apply: patients receive services free at the point of care, and the hospitals are reimbursed through block contracts with health authorities or extracontractual referrals. Some independent homoeopaths have had contracts with fundholding general practices and health authorities and have provided treatment for NHS patients.

View larger version (99K): [in this window] [in a new window]   A wide range of homoeopathic preparations, usually of low potency, are available over the counter. Most are used for self medication on a simple, symptom matching basis

Homoeopathic medicines can be purchased over the counter at chemists and health stores. They can also be prescribed on an FP10 form (GP10 in Scotland) by any doctor registered with the General Medical Council. About 10-20% of the UK population have bought homoeopathic products over the counter.

Homoeopathy is particularly popular in Europe: over 10 000 German and French doctors practise homoeopathy, and homoeopathic medicines constitute a substantial share of these countries' over the counter markets.

Training
The Faculty of Homoeopathy offers doctors a 40 hour course, approved for postgraduate education allowance, and an examination that lead to a primary care healthcare certificate. Intermediate and advanced courses are also available. The minimum entry requirement for the faculty's membership examination (MFHom) is 150-180 hours of study.

Regulation
The Faculty of Homoeopathy maintains a register of medical homoeopaths. The Society of Homoeopaths is the main regulatory body for practitioners without conventional healthcare qualifications and registers about 75% of homoeopathic practitioners in the United Kingdom.

	Acknowledgments

The picture of Samuel Hahnemann is reproduced with permission of the British Homoeopathic Association. The picture of a squid is reproduced with permission of Silvestris. The picture of a snowflake is reproduced with permission of Scott Camazine/Science Photo Library. The picture of laboratory mice is reproduced with permission of Daniel Heuclin/NHPA. The picture of vaccination is reproduced with permission of BSIP Laurent & Gille/Science Photo Library. The picture of over the counter homoeopathic remedies is reproduced with permission of Boots the Chemist.

	Footnotes

The ABC of complementary medicine is edited and written by Catherine Zollman and Andrew Vickers. Catherine Zollman is a general practitioner in Bristol, and Andrew Vickers will shortly take up a post at Memorial Sloan-Kettering Cancer Center, New York. At the time of writing, both worked for the Research Council for Complementary Medicine, London. The series will be published as a book in Spring 2000.