Curbing Herbal Remedies


23 May 2003

A woman goes into a pharmacy in London and asks for over-the-counter emergency contraception, licensed in the UK since 2001. The pharmacist asks several questions about her health including, to her surprise, whether she is taking any herbal preparations. He is acting on the growing concern about harmful interactions between herbal medicines and pharmaceuticals.

The sale of herbal supplements is big business and getting bigger, but rising use has been accompanied by increasing reports of health problems. The Australian government last month suspended the licence of the country's biggest complementary medicine company, after people taking a popular motion sickness drug suffered hallucinations. Thai officials recently banned the supplement V-1 Immunator because of false claims that it could cure HIV/Aids. Sean Riggins, a young American major league baseball player, died from heatstroke that doctors suspect was linked to ephedra, a herbal weight loss medicine.

Herbal supplements have gained wide acceptance over the past decade and some, if not all, may provide benefit. Evidence supports claims, for instance, that saw palmetto can relieve the symptoms of an enlarged prostate condition and that hawthorn may alleviate mild angina. Gingko shows some effect, in trials, on dementia.

Some experts are sceptical of the move to herbal remedies. "The benefits of herbal medicine rarely show validity in clinical trials, and the harm can be substantial," says Arthur Grollman of the State University of New York at Stony Brook.

But critics also say herbal treatments pose a serious risk for consumers, particularly in the US where the industry operates under a loose rein compared with Europe (see below). About 30 per cent of Americans, 20 per cent of Britons, and 70 per cent of Germans use them, according to researchers at the University of Exeter. In 2001, Americans spent $4.2bn (2.6bn) on herb and other plant remedies.

Reports of health problems arise for a number of reasons. First, patients taking herbal medicine sometimes stop taking proven drugs.

Second, in an industry far less regulated than pharmaceuticals, contamination and adulteration of herbal treatments occurs. Some supplements exported from China have tested positive for contamination with toxic heavy metals. For example, some irresponsible manufacturers have substituted substances promised on the label for cheaper ones - cow cartilage instead of shark cartilage, in one instance. In a recent case in Ireland, a skincare cream promoted as a herbal cure for eczema was found to contain powerful steroids.

Third, some herbal medicines are toxic. The US Food and Drug Administration this year forced ephedra makers to include warnings of potentially deadly side- effects. Retailers in some countries have withdrawn from sale, possibly temporarily, the popular herb kava-kava after liver failure cases were tracked to use of the drug. Three years ago, 105 patients mistakenly given the herb aristolochia to treat a skin condition in Belgium suffered kidney damage. Another 18 developed cancer.

But the greatest concern is potential damage from the interaction of herbal medicines with pharmaceuticals. Studies published in December in the New England Journal of Medicine showed the threat may be greater than previously thought.

The reports showed that many herbal remedies, harmless when taken alone, can turn deadly as they interact with conventional medicines. Popular antidepressant St John's wort, for example, adversely affects the medical impact of protease inhibitors to treat Aids, chemotherapy, heart drugs and even birth control pills.

Ginseng, considered innocuous on its own, can when combined with the medical blood clot treatment warfarin prevent clotting to a fatal extent. In Japan in 1996, at least 16 deaths were reported in hepatitis patients taking alpha interferon with the herbal medication minor bupleurum.

Herbal medicine supporters do recognise potential interactions with pharmaceuticals. "We advise our consumers to consult healthcare providers," says Jim Kinsinger, laboratory director in charge of quality assurance for Celestial Seasonings, a US-based herbal tea maker. "People are somewhat responsible for their own behaviour and choices." Research in the NEJM last year showed that just three out of 10 alternative medicine users share such information with their doctors.

So far, the popularity of herbal medicine among the public appears little affected by safety concerns. "People believe herbal supplements are safe because they are 'natural'," says Donald Marcus, an author of the NEJM report.

Marketing material for herbal supplement companies often includes the remark that such medications have been used "safely for thousands of years". Some point out that modern pharmaceuticals such as aspirin and the cancer drug Taxol were derived from plant extracts. Yet the high toxicity of Taxol is well- documented, and thousands of people die from gastrointestinal bleeding caused by aspirin each year.

The movement for more regulation is gaining momentum in the US, where the onus is on the FDA to prove supplements are harmful, rather than on herbal medicine makers to prove their drugs are safe.

Dr Kinsinger believes the industry could benefit from greater regulation, which would help identify irresponsible suppliers. "It does affect our sales when others give the products a bad name," he says.

Greater regulation is unlikely to guarantee the safety of herbal medicine. But industry proponents say a certain amount of risk is tolerable. "No herbal medication is going to be risk-free," says Edzard Ernst, professor of complementary medicine at the University of Exeter. "The fact that remedies are sold over the counter is very debatable in some cases. And we certainly need better control over quality. But it would be a shame to get rid of them."

Europe takes steps on herbal remedies to protect patient safety

Europe has taken a lead on the regulation of herbal medicines. While the US herbal medicine market may be closely tied to new-age spiritualism, Europe has a tradition of mainstream m edical herbalism stretching to the dawn of civilisation. Many of the largest European pharmaceuticals groups have activities in the herbal area.

Bayer of Germany abandoned Heroin as a cough medicine over a century ago when the side-effects became apparent. But this week it bought the marketing rights to a cannabis-based multi ple sclerosis product from GW Pharmaceuticals, a UK biopharmaceuticals company.

So it is no surprise that Europe has taken the lead in regulating the complex issues surrounding production and use of herbal medicines. New rules being prepared by the European Comm ission promise to take control of the safety and effectiveness of traditional remedies for the first time.

Herbal medicine is only a part of the complementary medicine field. But it is potentially the most dangerous, says David St George, an NHS consultant in clinical epidemiologyand chai rman of the British Acupuncture Accreditation Board, because of insufficient quality control, potentially harmful substances in some herbs and possible interactions with other drugs. "However, many conventional medicines als o have nasty side-effects and kill people, even though they are regulated," he comments. A long history of herbal prescribing by mainstream doctors, especially in Germany, means regulators are taking the same risk-benefit appro ach to regulating herbs as for conventional pharmaceuticals.

The new European rules are an extension of German laws introduced in the 1970s. Germany is the world's third largest market for pharmaceuticals, but number one for herbal remedies wi th a $3.5bn-a-year market. German doctors routinely prescribe herbal cures for depression, cardiovascular, digestive and lung problems. Several German pharmaceuticals companies have botanical subsidiaries, including Boe hringer Ingelheim, which sells a fatigue remedy through its Pharmaton subsidiary. Having a conventional healthcare system that has for a long time been open to herbs is very different to people just buying them over the cou nter, Dr St George points out.

The European legislation will see the extension of pharmaceutical rules to cover traditional herbal treatments. They will use using the same principle of balancing risk and benefit that is applied to conventional pharmaceuticals. Manufacturers will be subject to good practice rules for manufacturers akin to those expected of pharmaceuticals companies.

However, traditional herbal medicines will not face the degree of scrutiny applied to conventional medicines. Clinical trials costing millions of dollars are beyond the reach of most herbal medicine makers. Most have sales of less than $100m (62m) a year, a far cry from the $7bn that US pharmaceuticals giant Pfizer garners from just one drug, Lipitor, a cholesterol treatment. Herbal medicine makers may use an existing rule that allows pharmaceuticals companies to market drugs without conducting clinical trials if they can prove there is a track record of safe, effective use. The level of proof will be high, including a requ irement for publication in reputable scientific journals stretching back over 30 years.

The Commission's experts believe that will allow makers of effective traditional products to continue their legitimate trade while making it difficult for unscrupulous companies to l aunch new "wonder cures " without conducting full scale trials. Traditional medicines will also have to carry specific warnings about interactions with other medicines as well as a statement on whether their effectiveness has been proven in clinical trials.

"The safety issue raised in the US is valid and it is valid here," says Dr St George. "The European approach is very sensible. It is trying to make quality control for herbal product s the same as it is for other medicines. It has also taken a very pragmatic approach to the biggest stumbling block - efficacy." The regulations are not watertight, however. There is still a grey area around herbs sold as food supple ments. By not making medicinal claims the makers avoid regulation.

Those practising herbal medicine also face tighter regulation. The UK government has already brought osteopaths and chiropractors under a system of professional self-regulation. Herbal medicine and acupuncture specialists may soon face similar controls.

The Economist Intelligence Unit Limited 2003. All rights reserved.



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