Homeopathy

The concept of homeopathy is said to have originated with Hippocrates who thought of treating "like with like". It lay dormant until around 1790 when a German physician, Samuel Hahnemann, developed it further. He experimented on himself with quinine, that was used to treat ague, the old term for malaria and he found that he could reproduce the symptoms of the disease by increasing the dose.

He concluded that it was the ability of quinine to mimic the symptoms of malaria that enabled it to cure the disease. He began to test other substances on patients. He called the practice homeopathy from the Greek homoios (the same) and pathos (suffering). He used poisons such as arsenic and belladonna in smaller and smaller amounts and concluded that they seemed to have a more specific effect on his patients.

His ideas spread throughout Europe and North America in the 19th century and perhaps there was an attraction in a form of treatment that was no more effective than heavy metal and other poisons, purgation and blood letting but at least it was less toxic.

As the scientific medicine of the 20th century advanced, homeopathy fell from favour although a number of homeopathic hospitals were incorporated into the NHS in 1948. Homeopathy is known to be favoured by the Royal Family.

There has been considerable interest in "complementary and alternative medicine" with a House of Lords Select Committee Report in November 2000¹ and a subcommittee of the Royal College of Physicians set up to examine certain aspects. They reported in Clinical Medicine in 2003,² formerly the Journal of the Royal College of Physicians.

In the UK, 47% of people have used complementary and alternative medicine (CAM) at some times in their lives and 10% use some form of CAM each year.³ Users tend to be older, female and over 90% is purchased outside of the NHS. At least 10% of hospital physicians also use CAM as part of their clinical practice.⁴ A survey, conducted in 2001, estimated that one in two practices in England now offer their patients some access to CAMs.⁵ Of the various forms of CAMS, homeopathy has been one of the better ones in terms of quality and quantity of research.

The report of the Royal College of Physicians says that "Despite its apparent implausibility, homeopathy is among the most popular forms of CAM, with an estimated 470,000 regular users in the UK, and sales growing by around 12% annually."³

There are a wide variety of homeopathic preparations, including ones made from belladonna (deadly nightshade), arnica, chamomile, mercury and sulphur, sepia (extracted from squid ink), snake venom and even compounds extracted from bodily fluids.

Homeopathic medicines are prepared by serial dilution in steps of 1:10 or 1:100, denoted by the Latin numbers x and c respectively. At each step there is succussion, or vigorous shaking. The dilution most frequently sold in pharmacies is 6c, which is a 10^-12 dilution of the original "mother tincture". Hence it is likely that a 6c dilution will contain just a few molecules of the initial substance, but much higher dilutions, such as the 30c (10^-60) will probably not contain any of the original substance. A large number of homeopathic medicines have been described but about 200 are in regular use. Around 60% are of plant origin, the remainder mostly of animal origin, minerals and chemical salts and disease products.

In prescribing such treatment, the homeopath will enquire not just about the symptoms and signs of the disease, but also about constitutional factors peculiar to the patient, rather than the disease, including their psychological state, environmental reactions and body habitus.

The underlying philosophy is that the remedy will cause minimal symptoms of the disease and this will stimulate the body to begin the healing process.

The basic ingredient that is used is one that, if given in large enough quantities, would cause the symptoms of the disease. For example, the homeopathic remedy Allium cepa is made from an extract of onions. If a person chops onions, they make the eyes sting and water and the nose runs. The homeopathic philosophy of "like for like" states that a disorder with these symptoms would be cured by a small dose of onion. Hence Allium cepa may be used to treat hayfever.

If 6c preparations contain just a few molecules of the original substance and higher dilutions are unlikely to contain even a single molecule, the mode of action is difficult to explain. In 1988 a French immunologist called Jacques Benveniste published, a paper in Nature claiming to have detected effects of an immunoglobulin at ultramolecular dilution, using the human basophil degranulation test.⁶ Others have failed to reproduce his results⁷ and the matter has become known as "the Benveniste Affair" with an inference of scientific malpractice. In 1999 a multi-centre experiment using a related method showed positive results.⁸ This lead to the information medicine hypothesis that states that "water is capable of storing information relating to substances with which it has previously been in contact, and subsequently transmitting this information to pre-sensitised biosystems. The process is thought to be mediated by structural modifications of water, analogous to the storage of information by magnetic media." Such an idea would require a revision of our ideas about molecular structure and function and most people regard it as fanciful. Homeopathic remedies are made up with tap water, not distilled water and it seems most convenient that the water "remembers" the "good things" and not the "bad things" to transmit.

Because there is no rational explanation for how something works does not mean that it does not work. However, the concept of a medicine that is so dilute that it may or may not have a few molecules of the original substance in it, does tend to tax the bounds of feasibility.

Several years ago, practitioners of homeopathy, in keeping with many other practitioners of CAM, would argue that because their techniques are so tailored to the needs of the individual patient that they are not amenable to assessment by randomised controlled trials. This is untrue. The practitioner can go through the very detailed and meticulous history and at the end he writes his prescription in the usual way. A dispenser makes up the prescription and opens a sealed envelope to decide if he gives that or a similarly labelled bottle of unadulterated water from the tap. Neither the patient nor the practitioner who will assess the patient knows which the patient received and so the requirements for "double blind" are fulfilled. In theses circumstances, placebo is much easier than with physical treatments such as acupuncture, manipulation or reflexology.

There have been many publications about homeopathy over the years. In 1997 a review from Germany found 185 trials of which 119 met their inclusion criteria and 89 had adequate data for meta-analysis. The conclusion, published in The Lancet,⁹ was that homeopathy is more effective than placebo although they included papers looking at different clinical conditions and they were unable to state that it was more effective than placebo for any specific condition.

These findings were not readily accepted as proof of the efficacy of homeopathy and a review from Bandolier was highly critical.¹⁰ They praised the attempt to find and account for publication bias but they noted that:

• The median number of patients studied in each trial was 60
• There were 24 clinical categories
• There were four types of homeopathy
• There were 50 classes of homeopathic remedy

They noted that 42% of the trials found in favour of homeopathy but they observed that in trials of conventional medicine, no one would bundle together such a disparate group of clinical conditions.

In 2001 an education paper in the BMJ used the article in The Lancet as an example of the problems of meta-analysis.¹¹ They used funnel plotting and cut and fill. The concept is that if there are a number of trials, the bigger trials should have more consistent results and less scatter around the mean for all the trials whilst the results of smaller trials should be evenly spread above and below the mean. Hence a plot of outcome versus size of trial should produce a shape like an inverted funnel. Failure to produce such a shape suggests publication bias and cut and fill can be used to "discover the trials that have not been published." Using this technique they concluded that homeopathy is not an effective therapy.

There have been a number of Cochrane and other systematic reviews relating to homeopathy over the years. A review from Exeter of homeopathic arnica showed no benefit.¹² It was impossible to assess the poor quality evidence about dementia.¹³ The evidence about caulophyllum to induce labour is inadequate.¹⁴ Evidence was also too poor to assess homeopathy for asthma.¹⁵ A review from the Centre for Reviews and Dissemination from the University of York and published by NeLH also found no benefit from homeopathy for asthma.¹⁶The evidence about use of homeopathy to treat and prevent influenza and similar illnesses is also too poor.¹⁷ There is no apparent benefit for reducing weight.¹⁸ Poor methodology is also a barrier to assessing homeopathy for depression.¹⁹ A review from Switzerland, published in The Lancet, concluded that the effects of homeopathy are placebo.²⁰ This study was also covered by the Centre for Reviews and Dissemination from the University of York and published by NeLH²¹ with the title "Is this the end for homeopathy?"

The BBC television programme Horizon also investigated homeopathy²² and also came to the conclusion that it was ineffective.

In summary, there is some evidence that homeopathy does not work for certain conditions but for most conditions for which it is used the evidence is of such poor quality that it is impossible to form a conclusion. That is not the same as evidence of lack of efficacy but the plausibility of a system in which the medicine may contain no more than a few molecules of "active substance" and often none at all, does stretch the limits of credibility.

It would seem reasonable to believe that even arsenic, diluted to the level of just a few molecules, is unlikely to be toxic and the evidence relating to homeopathy does seem to suggest that it is as safe as may be expected. However, adverse outcomes can result if an ineffective treatment is used for a serious and treatable condition. Homeopathic immunisations are available and some parents opt for these for their children as they believe that they are safer than the conventional vaccines. However, they do not produce any antibody response and so, presumably, the children remain at risk of those serious diseases. Some non-medical practitioners claim that homeopathy is an effective substitute for immunisation but the Faculty of Homeopathy supports the Department of Health immunisation guidelines and provides an information sheet for parents.² The faculty also advises against the use of its products for malaria.

The House of Lords Select Committee was very keen on the regulation of all forms of CAM.¹ There is a Faculty of Homeopathy but practitioners have no compulsion for membership and it has no statutory power. Some may argue that regulation would give undue credibility to a system for which the evidence of effectiveness is poor to non-existent. On the other hand, it may ascertain that non-medical practitioners are properly trained and they do not persists with useless treatments for serious and treatable conditions.