Dietary supplements, which include substances known as botanical and herbal medications, are available without prescription and, unlike over-the-counter medications, are considered to be nutritional supplements rather than drugs. These substances are marketed in the United States without FDA or other governmental premarketing review of efficacy or safety, and with little government oversight of purity, variations in potency, or adverse effects. Purified nonherbal nutritional supplements such as dehydroepiandrosterone (DHEA) and melatonin are also used widely by the general public in pursuit of "alternative medicine." In the case of many herbal products and nutritional supplements, evidence from controlled clinical studies for their medical effectiveness is incomplete or nonexistent. A summary of the intended uses of some herbal products and nutritional supplements is presented in Table 60–1.
Table 60–1 Common Intended Uses of Some Botanical or Nutritional Supplements. ||Download (.pdf)
Table 60–1 Common Intended Uses of Some Botanical or Nutritional Supplements.
|Botanical or Nutritional Supplement||Common Intended Use|
|Echinacea||Decrease duration and intensity of cold symptoms|
|Ephedra (ma huang)||Treatment of respiratory ailments such as bronchitis and asthma, and as a CNS stimulant|
|Garlic||For cholesterol lowering and atherosclerosis|
|Ginkgo||Treatment of intermittent claudication, and cerebral insufficiency and dementia|
|Ginseng||Improvement of physical and mental performance|
|Milk thistle||Limitation of hepatic injury and as an antidote to Amanita mushroom poisoning|
|Saw palmetto||Improvement in symptoms of benign prostatic hyperplasia|
|St. John's wort||Treatment of mild to moderate depression|
|Coenzyme Q10||Improvement of ischemic heart disease and for Parkinson's disease|
|Glucosamine||Reduction of pain associated with osteoarthritis|
|Melatonin||Decrease jet lag symptoms and as a sleep aid|
|Alternative medicine||Treatments that are not generally recognized by the medical community as standard or conventional medical approaches|
|Controlled clinical trial||A clinical trial that compares a group of subjects who are receiving a treatment with a closely matched group of individuals who are not receiving a treatment. Chapter 5 describes clinical trials in more detail|
|Herbal medication||Plants or plant extracts that people use to improve their health|
|Nutritional supplement||A substance that is added to the diet to improve health and which usually contains dietary ingredients such as vitamins, minerals, amino acids, and enzymes|
|Placebo||An inactive medication made to resemble the investigational formulation as much as possible|
Leaves and roots of echinacea species (eg, Echinacea purpurea) contain flavonoids, polyacetylenes, and caffeoyl conjugates.
In vitro studies have shown that echinacea has cytokine activation and anti-inflammatory properties. There is some evidence for the efficacy of aerial (above-ground) parts of E purpurea plants in the early treatment of colds.
Toxicity and Drug Interactions
Unpleasant taste and gastrointestinal effects may occur, sometimes with dizziness or headache. Some preparations ...