Benefits of OTC availability

Factors that have led to an increase in self-medication include:

When used wisely, OTC drugs result in time and money savings, reduced workload for health professionals and, ultimately, reduced overall health-care costs. Scheduling some drugs as Pharmacy-Only (S2) or Pharmacist-Only (S3) also reduces the chance of abuse or misuse of these drugs, and leads to fewer adverse effects than might occur if these drugs were unscheduled and available without any professional oversight or counselling.

Safety and efficacy

Commonly, OTC drugs (see Table 3-1) are those considered relatively safe and effective for self-treatment by the public, assuming good manufacturing practices are followed by the manufacturer and the label directions are followed by the consumer. They are drugs with a high therapeutic index (safety margin) and/or are available in low doses or in limited supplies.

Unscheduled drugs

Drugs that are considered sufficiently safe not to require any controls, and many herbal products for which claims of therapeutic efficacy are not made, are unscheduled in the SUSDP and may be sold through many retail outlets, including supermarkets, health-food stores and general merchants, and purchased without prescription or counselling by a pharmacist, i.e. ‘over the counter’. Such drugs include most vitamins and minerals, sunscreens, medicated shampoos, and small packs of simple pain-relievers (analgesics) such as paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen. These may also be included under the umbrella of OTC drugs, depending on the definition.

Schedule 2 and 3 drugs

Schedule 2 (Pharmacy-Only) drugs are non-prescription drugs that can be bought off the shelf from a pharmacy where professional advice is available (and possibly also from some supermarkets). Schedule 3 (Pharmacist-Only) products are considered to require a pharmacist’s advice in their supply, to ensure they are used safely and effectively; indeed the pharmacist has a professional responsibility to counsel the person on safe administration of the drug. These also can be purchased without a prescription.

Drugs in multiple schedules

A drug should not be considered to be ‘set-in-concrete’ as either OTC or Prescription-Only—a drug may fall into various drug schedules depending on the dose to be administered, the strength of formulation, number/amount in the pack, the route by which it is given or the condition for which it is indicated; and even (in Australia) the state in which it is prescribed. In certain situations, costs of drugs may be subsidised when prescribed but not when bought OTC. Examples of some drugs that ‘move around’ among Schedules 2, 3 and/or 4 are shown in Table 3-2. For example, ranitidine low-dose tablets (150 mg) for heartburn in packs of 14 are unscheduled, whereas packs of 28 are S2 and higher dose or larger packs for treatment of peptic ulcers are Prescription-Only.

Table 3-2 Examples of prescription drugs also available OTC in Australia

IU = International Units of activity.

Changes between schedules

The TGA may from time to time suggest that Prescription-Only drugs be changed to OTC status. This is based on expert findings that the drug in a particular formulation is safe and effective for use by the general public, that drug information is available and that compliance is appropriate. Certain formulations of salbutamol, hydrocortisone and ranitidine, for example, have been ‘moved down’ to S2 or S3 Schedules, as shown in Table 3-2.

On the other hand, experience sometimes shows that particular drugs do need the extra safeguards of being classified S4 (Prescription-Only), which encourages doctors and pharmacists to exercise professional judgement as to the prescribing of this drug and advising the patient. For example, all insulin formulations were moved back to Schedule 4 from Schedule 3, where they had been placed for a few years.

Analgesics

Pain is one of the most common and feared symptoms. For minor pain such as headache, toothache, muscle and joint aches, swelling (inflammation) and fever, many people obtain relief inexpensively with OTC analgesics. Examples are paracetamol (Drug Monograph 3-1), aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), some of which are available OTC. Analgesic agents are discussed in detail in Chapter 16, where morphine and aspirin are considered as the prototype analgesics.

Antacids

Various medical conditions, overeating, eating certain foods or drinking excess alcohol may result in dyspepsia (stomach upset), heartburn and indigestion. Antacids— drugs that buffer, neutralise or absorb hydrochloric acid in the stomach, and thus raise gastric pH—are commonly used for these conditions. The major ingredients in antacids are alkalis such as bicarbonate, sulfate, trisilicate and hydroxide, as aluminium, magnesium or calcium salts (see Chapter 29 and Table 29-1). Simethicone may be added to these preparations as a de-foaming or anti-gas agent.

Laxatives

Laxatives—drugs given to induce defecation—may be classified according to their site of action, degree of action or mechanism of action (see Chapter 30). Many older people are overly concerned about their bowel habits, and laxatives are often misused or abused, leading to a cycle of alternating constipation and diarrhoea.

Antidiarrhoeal agents

The term diarrhoea describes the abnormal passage of stools with increased frequency, fluidity or weight, and an increase in stool water excretion. Acute diarrhoea is usually self-limiting and resolves without sequelae. Excess fluid and electrolytes can be lost and severe morbidity and even death can occur in malnourished populations, the elderly, infants and debilitated people. Antidiarrhoeal drugs available OTC include formulations of opioids (codeine, loperamide, diphenoxylate), antimuscarinics (atropine, hyoscyamine, hyoscine), adsorbents (kaolin), demulcents (pectin), antiflatulents (simethicone) and probiotics such as bovine colostrum and Lactobacillus fermentum.

Cough/cold preparations

Every year, especially in winter, millions of dollars are spent (probably wasted) on cough, cold and influenza preparations such as antitussives, antihistamines, expectorants and decongestants (see Chapter 28). Many cough/cold products contain a combination of ingredients, some of which are in sub-therapeutic doses or are unnecessary for the particular symptoms they purport to treat. Such preparations are not considered rational and may not be safe or effective.

Antihistamines

Antihistamines are drugs that compete with histamine for its H₁-receptor sites. They are commonly used to treat allergic symptoms, itching, motion sickness and as sedatives. Part of their usefulness in ‘cough and cold cures’ is due to their antimuscarinic actions, which help dry up nasal and airways secretions, and part is due to their sedative effects.

Vitamins

Vitamins are organic compounds essential in small amounts for the body to maintain normal function and development. They were so named as a contraction of the term ‘vital amine’, as the first such essential compounds identified were amines. Many of the vitamins are considered in detail in later chapters, especially:

Vitamins are often formulated in ‘multi-vitamin’ preparations, and also in combination products particularly for children, teenagers, pregnant women or elderly people, intended to appeal to people thinking they need extra supplements.

There is a widespread fallacious view in the community that natural products (such as vitamins) are safe, whereas synthetic products have side effects (see footnote later in this chapter). However, overdoses of vitamins, especially of the fat-soluble vitamins that can accumulate in the body, can be toxic—see Clinical Interest Box 48-4 for a famous fatal case of vitamin A overdose. Similarly, taking high-dose antioxidants (vitamins A, C, E) does not prevent cancer, common colds, eye disease or old age, and can be toxic.

Minerals

Minerals are inorganic substances (not containing carbon); some are required in the diet to maintain health. Deficiency is comparatively rare, except for calcium and iron. Essential minerals are:

Other dietary supplements

Other dietary supplements are of a wide range and number, and are more the focus of nutrition—or Complementary and Alternative Medicine, see later this chapter—than of pharmacology. Many have been used in sport in attempts to enhance performance, e.g. pyruvate or creatine (see Clinical Interest Box 49-4); however, the fact that they are allowed by bodies such as the International Olympic Committee shows that they have never been proven to enhance performance. Others are used in attempts to enhance formation of neurotransmitters, as prophylaxis against heart disease (vitamin E, folic acid) or cancer (selenium, vitamin E) or to assist in other physiological functions deemed inadequate (coenzyme Q10 as an antioxidant; melatonin in sleep management—see Clinical Interest Box 3-3).

The terms ‘nutraceuticals’ and ‘functional foods’ have been coined to cover a wide range of (usually) natural supplements that may confer health benefits. Examples are: soy protein and phyto-oestrogens (sources of oestrogens, for menopausal symptoms and bone health), citrus flavonoids (antioxidants, anticancer and cholesterollowering), red wine and tea tannins (cardiovascular disease), dietary fibre (coronary heart disease and gastrointestinal tract regularity), probiotics, active microorganisms in yoghurt (balance gut microflora) and omega-3 fish oils (cardiac arrhythmias, insulin resistance and arthritis); see Table 3-3.

Table 3-3 Common kitchen or folk remedies

Note that ‘kitchen remedies’ also include various herbs and spices (see Table 3-4).

Source: Braun & Cohen 2007, inter alia.

Self-diagnosis

Self-medication usually follows self-diagnosis of the signs and symptoms of a clinical condition. Generally, the public may consider most illnesses to be minor; however, self-treating a potentially serious condition with OTC medications may mask the condition and delay the seeking of professional help for appropriate treatment.

Adverse effects and drug interactions

OTC medicines may contain potent drugs, many of which were previously prescription-only. There has been a trend recently for the TGA to transfer more drugs to OTC status. Health-care professionals should be aware that many OTC products (new and old) are capable of producing both desired and undesirable effects, drug interactions and drug toxicity.

Labelling

The TGA regulates the appearance and content of OTC package labelling so that important information is provided in terms that are likely to be read and understood by the average consumer. Many consumers may nevertheless find that some labels are confusing and often the print is too small to read, especially by elderly people. OTC labelling that is difficult to understand and implement may result in unsafe and possibly improper use of the medication. Restrictions on labelling, packaging and storing of OTC drugs are useful but also have the potential for adding to costs and reducing competition in the marketplace.

Drug marketing

In Australia, all therapeutic goods must be registered by the TGA before they can be supplied. Therapeutic goods include anything represented to be or likely to be taken or used for a therapeutic purpose, including for disease prevention or treatment; modifying a physiological process; testing, controlling or preventing conception; or replacing or modifying body parts. (There are a few specific exclusions of well-known ingredients with a long history of safe use, such as vitamins, sunscreens and medicated soaps.) Therapeutic goods must be assessed and monitored to ensure safety, efficacy and quality. Manufacturers must be licensed and manufacturing processes must comply with the principles of ‘Good Manufacturing Practice’. Advertising is also regulated by the TGA. This compares favourably with the situation in the USA, where many goods are allowed onto the market as OTC products with little regulation, provided that they are identified as ‘Generally recognized as safe and effective’.

While such regulations are essential to protect the public, it can be argued that the scheduling of substances reduces individual freedoms by placing restrictions on who may supply or administer substances to whom and in what circumstances. This could be seen as an impediment to competition and a limit on consumer access to and choice of drugs.

Potency and efficacy

Another important concept to understand is the difference between drug potency and drug efficacy (effectiveness). Drug potency relates inversely to the amount of drug required to produce a desired effect: the more potent the drug, the lower the dose required. Potency determines dose but is rarely an important aspect to consider when selecting a drug—actions, adverse effects and pharmacokinetic aspects are more relevant clinically. When drug manufacturers claim that their product is more potent than another product, this usually means that less of the drug is necessary to produce the same effect, but does not mean that the more potent drug is also the more effective drug.

Combination products

Combination products may contain substances that are not necessary for the person’s symptoms. If the individual has an adverse reaction to the combination drug, it will be difficult to determine the ingredient responsible. Change in dosage will alter the dose of all active ingredients, which may not be appropriate. Raising the dose may cause accumulation of the drug with the longest half-life, leading to toxicity.

OTC medicines are drugs

OTC products are drugs (chemicals administered for useful effects on the body) and should be reported to any health-care provider when a drug history is being taken. A question phrased in neutral terms such as ‘Do you ever take any medicines?’ is likely to elicit a more positive and instructive response than ‘What drugs are you on?’ Instructions and warnings on the label need to be followed carefully. If the instructions seem unclear, it may be helpful to ask the pharmacist for clarification. If the symptoms for which the OTC drug is being taken are not relieved in an appropriate time as indicated on the label, a health-care provider should be consulted; many patients while self-medicating have delayed attending for professional health-care for so long that their condition has become untreatable.

‘Take as directed’

The old Latin abbreviation ‘mdu’, meaning ‘take as directed’, is now considered unhelpful. Patients attending a consultation are often anxious and inattentive when prescribers or pharmacists give advice about conditions and drugs, and later forget what directions were given. It is much more effective for the instructions to be written on the package label in specific terms such as ‘Take one tablet with a full glass of water three times a day after meals’.

All solid-dose oral medications (tablets and capsules) should be taken with a full glass of water, and the person advised to remain sitting or standing up for about 15–30 minutes afterwards, to reduce the potential for oesophageal irritation or injury. If the person has a problem with dry mouth or minor problems in swallowing, drinking a small amount of water before taking a tablet or capsule is helpful. If the drug is a sustained-release or enteric-coated form, it should be swallowed whole. If the medication is in a liquid form, a specially marked measuring spoon or glass should be used to measure each dose accurately.

Multiple dosing with similar drugs

Many products may have the same or very similar active drugs, which may differ in strength, dosage form (liquid, tablet, capsule) or in other ingredients, contributing to the problem of polypharmacy (considered in Chapter 2, see Clinical Interest Box 2-3). If the ingredients are not carefully checked, accidental overdosing is possible by taking the same or similar drugs in many different products. This is particularly a risk with NSAIDs: for example a woman may be prescribed an NSAID for an inflammatory condition, then take another NSAID for period pain and then aspirin for a headache, without realising the risk of compounding adverse drug reactions from three similar drugs.

Another aspect of different products having the same ingredients is that it may allow for product substitution. For example, dozens of antacid products are available that primarily contain only four or five recognised active ingredients. Many OTC antacids are thus virtually duplicate preparations. The generic or ‘home-brand’ product is often as effective as the ‘upmarket’ brand name product, so there is usually little, if any, advantage in consumers buying the more expensive item.

Tampering with packages

Consumers should check the selected package for tampering. There have been recent instances of commercial sabotage, in which, for example, disgruntled former employees tampered with products to insert dangerous ingredients. Most products are now contained in tamperresistant packaging, which allows the consumer to detect signs of tampering. If the package is suspect, it should be taken to the pharmacist or store manager. The expiry date should also be checked.

Sensitivity to ingredients

Consumers should read labels very carefully if they have ever had an allergic or unusual response to any medication, food or other substance, such as food dyes or preservatives, to ensure that such an ingredient is not included. Caution should be used if the individual is on a special diet, such as low-sugar, low-sodium or phenylalanine-free, because many OTC drugs contain more than just their active ingredients, and oral liquid preparations may contain high concentrations of sugar or alcohol. Women who are pregnant or breastfeeding should not take OTC medications without first consulting their health-care provider. People with underlying medical conditions, such as hypertension or diabetes, should read labels carefully to assess whether the medication may be contraindicated in their condition.

Storage

Unless instructions state otherwise, both prescription and OTC medicines should be stored in closed containers in a cool dry place, out of the reach of children; not stored in the bathroom, near windows or in damp places because heat, moisture and strong light may cause deterioration or loss of drug potency. ‘Use-by’ dates should be carefully observed.

Herbal products in Australia

The principal outlets for sale of herbal products in Australia are health-food stores, dispensaries of complementary and alternative practitioners, traditional herbal dispensaries operated by particular ethnic groups, and the Internet; pharmacies and supermarkets may also carry these products. Relevant information on ginseng is summarised in Drug Monograph 3-3, in the same format used for all other drugs, as an example of a herbal remedy; however, it will be noted that information is often unavailable for herbal products. The definitive textbook in this field is Herbs and Natural Supplements: An Evidence-Based Guide, 2nd edn (Braun & Cohen 2007).

Herbal products in the United Kingdom

The British have a long history of interest in and clinical use of herbal remedies. There is an official British Herbal Pharmacopoeia 1996, produced by the British Herbal Medicine Association. This gives detailed monographs for about 170 standard herbal remedies, with information on their characteristics, identification, quantitative standards and claimed actions. Appendices give methods of analysis to determine the strength and purity of the preparations.

Non-herbal supplements

Essential oils and aromatherapy

Other pharmacological natural products include essential oils and the extracts used in aromatherapy, Bach flower products and scented candles, in which the volatile oils, esters, alcohols and many other chemicals from the plants may contribute to the aromas and their effects on the senses and body functions. Aromatherapy with wildflower essences is used in some hospitals for stress and pain management. Tea-tree oil has become one of the most commonly used natural remedies in Australia, and its popularity has spread internationally. The essential oil from Melaleuca alternifolia (see Figure 3-1B), tea-tree oil contains many active constituents, including terpenes such as cineole. Its main proven actions are antifungal, antibacterial and antiviral (against herpes simplex); it is used particularly in skin infections and in podiatry, and as a cosmetic.

Figure 3-1 Some Australian plants from which herbal medicines are extracted:

A. Eucalyptus;

B. Melaleuca leptospermum grandiflorum;

C. Barringtonia asiatica;

D. Euphorbia peplus.

Homeopathy

Homeopathy is a form of treatment in which substances (minerals, plant extracts, chemicals or microorganisms) that in sufficient amounts would produce a set of symptoms in healthy persons, are given in minute amounts to produce a ‘cure’ of similar symptoms. It is based on the teachings of a German physician–pharmacist Samuel Hahnemann (1755–1843). Homeopathic ‘remedies’ based on extracts of plant drugs, such as atropine, quinine and arnica, and copper, zinc, calcium and mercury are used.

The homeopath is said to encourage the body’s own healing by stimulating a ‘vital force’ by administration of an extract of fresh natural product, a process known as ‘proving’ the drug. The mother tincture is then diluted thousands of times,² with vigorous shaking and tapping (succussion), which is said to release the power to heal. Each serial dilution is said to increase the ‘power’ of the medicine. Care must be taken not to contaminate the preparation with anything that could affect its ‘potency’. Formulations include tablets, drops, tinctures and powders.

The lack of scientific rationale for homeopathic principles, in particular the total negation of accepted dose–response relationships, and lack of scientifically acceptable and repeatable evidence for clinical efficacy in randomised controlled double-blind trials, make this modality anathema to pharmacologists trained in pharmacodynamic principles. It is nonetheless widely practised in Europe and followed by many influential people, including royalty. (In 2010 the UK government announced its intention to stop subsidies for homeopathic treatments, due to lack of any evidence of efficacy.) In Australia, homeopathic preparations are exempt from regulation by the TGA unless they contain ingredients of human or animal origin, but labels must state that they are not approved by the TGA, and cannot claim to cure serious illnesses.

A recent meta-analysis (Ernst 2010) systematically reviewed all relevant papers for and against homeopathy, using the Cochrane Database as the source of reviews. The author, himself the Director of Complementary Medicine at the Medical School of the University of Exeter, UK, concluded that ‘the most reliable evidence… fails to demonstrate that homeopathic medicines have effects beyond placebo’.

Traditional Chinese medicine

In traditional Chinese medicine (TCM), maintaining an energy balance in the body is considered most important; a balance between yin (negative) and yang (positive) forces is necessary to maintain good health. The Chinese physician may thus prescribe a variety of interventions such as herbal therapy, acupuncture, moxibustion, diet changes, exercise, meditation or the services of a spiritual healer. Herbal remedies have been studied for thousands of years, so this knowledge is used with other therapies to achieve a balance within the body to help regain and maintain good health.

In Chinese herbal medicine, herbs are either taken orally or applied externally to correct the physical disorder. Herbs are described by their properties, e.g. heat-clearing herbs, Qi-regulating herbs or Yin-tonifying herbs. Texts such as the Chinese Materia Medica (Zhu 1998) describe the philosophy and techniques of TCM materia medica (pharmacology), with guidelines for the harvesting, production and application of the materials. Monographs on products may describe the chemistry, pharmacology, adverse effects and toxicity, the traditional description, indications for use and applications of the remedy, and the dose and how it is administered.

In TCM it is believed that herbal preparations are much more effective when used in a balanced formula (see case history in Clinical Interest Box 3-6), and that ingredients have synergistic effects, i.e. actions are magnified when taken as mixtures (however, there is little scientific evidence for this). Ginseng (Drug Monograph 3-3), for example, may energise the body (especially the lungs, spleen and pancreas) but it can also cause strong adverse effects if used alone. The ginsenosides in ginseng can constrict arteries but if ginseng is combined with other herbs such as kudzu or astragalus, the adverse effects are believed to be balanced. Another example is the combination of bitter orange, ginseng and ginger; the bitter orange is the key herbal that stimulates the body’s vital energy (Qi), ginseng energises the body by providing a warmer energy and ginger is included as an assisting herbal (i.e. it helps to relax muscle tissue). This combination is chosen for the individual effects plus the effects in combination. This combination may be used to treat muscle aches (muscle relaxant) and digestive tract problems, and in people who need to strengthen their Qi energy.

African traditional medicine

Traditional medicine practitioners in many African countries include herbalists, midwives, bone setters, faith healers and spiritualists. Disease is considered to arise not only from physical and psychological causes but also from astral, spiritual and other esoteric causes. African traditional medicine provides holistic treatment, and may include herbal, mineral and animal remedies, administered orally as liquids, topically as powders, ointments or balsams, or by inhalation. Parenteral routes are rarely used. Other types of African traditional medicine include diets and fasting, hydrotherapy or dry heat therapy, surgical operations, bloodletting, spinal manipulation, faith healing and occultism.

Several important drugs have come into Western medicine from traditional African remedies, including physostigmine (an anticholinesterase), yohimbine (an α-receptor antagonist resembling the ergot alkaloids), reserpine (an alkaloid from Rauwolfia and a former antihypertensive and neuroleptic agent that caused severe depression) and ouabain (from Strophanthus species, a cardiac glycoside).

Currently, in South Africa it is estimated that there are over 350,000 traditional healers, offering medicinal plants to 60%–80% of the population. Plants are used as herbal extracts and also as muthi, plant material processed to be used to achieve healing, cleansing and protection from evil spirits or witchcraft. Biomedically valuable indigenous plants, including Pelargonium species, Harpagophytum and ‘devil’s claw’, are being assessed for pharmacological activity, as part of nation-rebuilding in the ‘African Renaissance’; however, there are concerns about the ethics of ‘bio-prospecting’ to exploit traditional knowledge for profit (see Reihling [2008]).

Ayurvedic medicine

Ayurveda, the indigenous healing system of India, has been practised there for more than 5000 years, focussing on prevention and self-care to restore health balance. It has been called ‘the science of long life’, as it takes a holistic approach to health and lifestyle management, incorporating exercise, diet, life activities, psychotherapeutic methods, massage and botanical medicine. Common spices are utilised, as well as herbs, herbal mixtures and preparations known as Rasayanas. Research and clinical trials are being carried out on the use of Ayurvedic medicine in treatment of anxiety, depression, hypertension, diabetes mellitus, tuberculosis and Parkinson’s and Alzheimer’s diseases.

Traditional Indian spices are utilised in Ayurvedic medicine, and good results have been achieved with turmeric in wound healing, rheumatic disorders, rhinitis, gastrointestinal disorders and worm infestations; with curcumin in decreasing DNA damage and reducing mutations and tumour formation; and fenugreek seeds in reducing blood glucose and lipid levels. Garlic, onions and ginger have all been shown to impair the process of carcinogenesis.

Traditional medicine in the Pacific region

In the southwest Pacific region—from Palau and the Federated States of Micronesia in the west, through East Timor, the Solomon Islands, Vanuata, Tuvalu, Fiji, Samoa, Tonga, to the Cook Islands and Kiribati in the east—waves of settlements with Pacific peoples and then colonists from Europe brought with them plants that became adapted to coastal areas, grasslands, tropical rainforests and gardens. Many plants were found to be useful for medicinal purposes, and all the immigrant groups brought with them traditional remedies, leading to a rich mixture of medicine practices.

In Fiji, diseases were traditionally considered to be mate vayano—illnesses of the body, resulting from accidental circumstances, e.g. coughs, colds, headache and injuries, or mate ni vanua—diseases of the land, caused by spirits, magic, behaviour or sorcerers. The dauvakatevoro (people who could control evil spirits) might use herbs, secretions of the victim or yagona (kava preparations); potions from plants were believed to have magical powers to change emotions or morals. For example, leaves of kalabuci damu were chewed to ensure safety on unfamiliar tracks; those who dug graves must eat a kura leaf afterwards; and moli karokaro (lemon trees) were grown near houses for fruit and for protection. Prior to white settlement, there were few acute diseases in Pacific island countries, but European contact brought new epidemics: measles, ’flu, whooping cough, chickenpox, smallpox, cholera and venereal diseases, which devastated the vulnerable populations. As living standards have changed towards Western lifestyles, it is now the non-communicable diseases that are the major public health problems, such as obesity, diabetes and cardiovascular disease.

Traditional remedies from plants were used as ‘tonics’, emetics, inhalations, ointments, poultices, liniments and to treat infections, wounds, infertility, menstrual problems, respiratory disorders etc. Many of these have been researched (see Cambie and Ash [1994]) and their chemical properties and pharmacological activities verified. The best-known Pacific herbal product is of course kava (yagona, or grog), an extract of powdered root and stem of Piper methysticum—discussed in Chapter 21 in the context of social pharmacology and drug dependence. Apart from its use in social and religious ceremonies, kava is used medicinally as a diuretic, to treat kidney and bladder problems, as a panacea for various complaints (cough and cold, sore throat, convulsions), as a contraceptive for mothers with infants, and the leaves are crushed and applied to wounds.

Some other examples of traditional Fijian remedies are:

Adverse drug reactions

Just as prescribed and synthetic drugs can cause adverse reactions, so many natural products can cause harm,³ depending on the herb itself, the quantity consumed, whether the correct plant or part of the plant is present in the product, the presence of contaminants and other factors. Although not many herbal toxicities are reported in the consumer literature, some very serious problems have been reported in the medical literature (see Table 3-5). Chaparral, for example, was promoted in the USA as a blood purifier and cancer cure (not on the label, which would then involve the FDA, as this is a medicinal use promotion), but its use has caused serious liver damage in some patients. In at least one case the need for a liver transplant was reported after 10 months of chaparral use.

Table 3-5 Some herbal preparations with a potential for toxicity

The Australian TGA issues alerts about complementary medicines on its website; alerts have included warnings of interactions between St John’s wort and many prescription medicines, and that Chinese herbal medicines in Australia have been found to contain samples of Aristolochia, a herb considered so toxic that it is banned. Animal products can also be toxic: cases have been reported of acute renal failure following ingestion of fish gallbladder as a folk remedy; carp gallbladder contains 5-α-cyprinol sulfate, which is toxic to the liver and kidneys.

Drug interactions

Just as prescribed and OTC drugs can interact by various mechanisms—pharmaceutical, pharmacokinetic and pharmacodynamic (see Chapter 9)—so CAM drugs can interact with each other, with food and with other drugs the person is taking.

The mushroom Kombucha has been associated with illnesses and death. A tea made from Kombucha is said to be a tonic, but several people have been hospitalised and at least one woman died after taking this product. The cause could not be directly attributed to the Kombucha, but several theories were offered, e.g. the tea might have reacted with other medications that the woman was taking, or bacteria might grow in the Kombucha liquid and, in patients with suppressed immunity, might prove to be fatal.

The toxicity of Kombucha indicates potential problems that may not have been considered before taking the product; that is, what effect would the active ingredients in the herb have on other medications that the individual may be consuming? Natural or herbal products may contain active ingredients that have not been identified and that, in combination with other medications or other herbal products, may cause serious drug interactions or may interfere with the results of laboratory tests.

The risk of interactions rises exponentially with the number of medicines a person takes. Many clinically significant interactions with herbal remedies are being documented and published as lists in journals and as posters and brochures for health professionals to consult (Braun & Cohen 2007; Fugh-Berman 2000; Faulding Healthcare 2000). Virtually all commonly used herbal remedies have some serious drug interactions related to their use, so such lists should be consulted before advising their use and particularly if adverse effects or interactions are suspected.

Contaminated products

Contaminants (adulterants) are frequently found in natural products. They may be natural, such as the heavy metals lead, arsenic, mercury and thallium found in some imported preparations. In other cases, synthetic drugs have been found in supposed natural products, including NSAIDs in supposed ‘herbal’ preparations for the treatment of inflammation, and synthetic oral hypoglycaemic agents in herbs used to treat diabetes. Such contamination is potentially very dangerous if the patient is taking the ‘natural’ products in addition to prescribed drugs or is allergic to any of the unexpected ingredients.

CAM therapies other than herbal remedies have also caused serious adverse effects. Examples are:

Regulation in Australia by the TGA requires that products be manufactured, prepared and standardised according to the standards of Good Manufacturing Practice; however, adulterated, contaminated or poor quality products may be sold by unscrupulous practitioners, as the Pan Pharmaceuticals episode showed (see below).