McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 6  Challenges to effective drug therapy

Because many OTC drugs interact with prescription drugs, with possibly serious adverse or toxic effects, it is important that the healthcare provider ask specifically when taking a drug history whether the person is taking any OTC drugs or other medications. Many people do not consider OTC drugs to be “real” drugs and do not mention their use when reporting a drug history to their healthcare provider. Every drug-teaching session should include information on which particular OTC drugs must be avoided or advice to check with the healthcare provider before taking any other medications or OTC products. ALTERNATIVE THERAPIES AND HERBAL MEDICINE Another aspect of the increasing self-care movement is the rapidly growing market of alternative therapies and herbal medicines. Herbal medicines, both commercial and traditional (such as Rongoa– Ma– ori or Indigenous Australian) and alternative therapies are found in ancient records and have often been the basis for the dis- covery of an active ingredient that is later developed into a regulated medication. Today, alternative therapies can also include non-drug measures, such as imaging and relaxation. There is a considered element of the placebo effect in using some of these therapies. The power of believing that something will work and that there is some control over the problem is often very beneficial in achieving relief from pain and suffering. The challenge for the healthcare provider is to balance the therapies that the person wishes to use with the medical regimen that is prescribed. This may involve altering doses or timing of various drugs. See Appendix F for an extensive listing of alternative and complementary therapies. Currently, these products are not controlled or tested by the TGA or MEDSAFE; they are considered to be dietary supplements, and therefore the advertis- ing surrounding these products is not as restricted or as accurate as with classic drugs. Consumers are urged to use the “natural” approach to medical care and to self-treat with a wide variety of products. Numerous Internet sites point out natural treatments that can be used to cure various disorders. Television ads and magazine spreads push the use of these products in place of prescribed medications. Many people who want to gain control of their medical care or who do not want to take “drugs” for their diabetes, depression or fatigue are drawn to these products. Appendix F lists common alternative therapies and their suggested uses. Several issues are of concern to the healthcare provider when a person elects to self-treat with alterna- tive therapies. The active ingredients in these products

have not been tested; when test results are available, often the tests were for only a very small number of people with no reproducible results. When a person decides to take bilberry to control diabetes, for example, the reaction that will occur is not really known. In some people, the blood glucose level might decrease; in others, it might increase. The incidental ingredients in many of these products are unknown. Many ingredients come directly from plants or from the conditions under which they grow, such as the fertiliser used for the plant, or depend on the time of the year when the plant was harvested. The other ingredients that are compounded with the product have a direct effect on its efficacy. Saw palmetto, a herb that has been used successfully to alle- viate the symptoms of benign prostatic hypertrophy, is available in a wide variety of preparations from different manufacturers. A random sampling of these products performed in 2000 revealed that the contents of the identified active ingredient varied from 20% to 400% of the recommended dose. It is difficult to guide people to the correct product with such a wide range of variability. People often do not mention the use of alternative therapies to the healthcare provider. Some people believe that the healthcare provider will disapprove of the use of these products and do not want to discuss it; others believe that these are just natural products and do not need to be mentioned. With the increasing use of these products, however, several drug interactions that can cause serious complications for people taking prescrip- tion medication have been reported. People with diabetes who decide to use juniper berries, ginseng, garlic, fenu- greek, coriander, dandelion root or celery to “maintain their blood glucose level” may run into serious problems with hypoglycaemia when they also use their prescrip- tion antidiabetic drugs. If the person does not report the use of these alternative therapies to the healthcare provider, extensive medical tests and dose adjustments might be done to no avail. St John’s wort, a highly advertised and popular alternative therapy, has been found to interact with oral contraceptives, digoxin (a heart medication), the selective serotonin reuptake inhibitors (used for depres- sion), theophylline (a drug used to treat lung disease), various antineoplastic drugs used to treat cancer and the antivirals used to treat acquired immune deficiency syndrome (AIDS). People using St John’s wort for the symptoms of depression who are also taking Prozac (fluoxetine) for depression may experience serious side effects and toxic reactions. If the healthcare provider is not told about the use of St John’s wort, treatment of the toxicity can become very complicated. Asking people specifically about the use of any herbal or alternative therapies should become a routine part of any health history. If a person presents with an unexpected reaction to a medication, ask them about any herbal or natural remedies they may be using. If a