Herbal Drugs: Therapeutic use, Treatment. Herbal Drugs rehab.

Last modified: Sunday, 31. May 2009 - 3:56 pm

Official names: Botanicals, nutraceuticals, phytophar-maceuticals, dietary supplements, natural supplements
Street names: Ginseng (Panaxginseng), echinacea (Echinacea purpurea), ginkgo (Ginkgo bibba), garlic (Allium sativum), saw palmetto (Serenoa repens), St. John’s wort (Hypericum perforatum). St. John’s wort is also known as hard-hay, amber, goatweed, Klamath weed, and Tipton weed. Garlic supplements are Garlix, Gar-Pure, and Cardiomax
Drug classifications: Not scheduled, dietary supplements

 

Key terms

ACTIVE INGREDIENT: The chemical or substance in a compound known or believed to have a therapeutic effect.
CLINICAL TRIAL: A scientific experiment that tests the effect of a drug in humans.
DECOCTION: A tea or soup made from boiling herbs in water.
FLAVONOIDS: Chemical compounds found in many herbal drugs. Flavonoids may help fight off infections and clear the body of harmful free radical molecules.
PATENT MEDICINES: Medical remedies of doubtful value commonly sold in the 1800s and 1900s. Many patent medicines were herb-based, although they were often laced with alcohol, narcotics, and other drugs.
PLACEBO EFFECT: A psychological phenomenon noted by researchers in which patients who receive a phony medication feel better and report improvements in subjective symptoms such as pain or depression.
TINCTURE: An extract of an herb made by soaking it in glycerine, alcohol, or vinegar for several weeks, then straining the liquid.

 

Overview

Herbal drugs are made from the roots, stems, leaves, bark, fruit, seeds, or flowers of various plants known or believed to have medicinal properties. Many conventional drugs are also derived from plants. In fact, the word “drug” comes from the French word drogue, meaning “dried herb.”
Herbal and conventional drugs differ significantly, however. When a conventional drug is derived from a plant, this drug is a purified form of the specific substance in the plant that is proven to have a beneficial medical effect. This substance, called the active ingredient, is delivered to the patient in a precise amount, or dose. Herbal drugs, in contrast, are made up of all the other substances and chemicals in the plant, in addition to any active ingredient they might contain. Sometimes, manufacturers of an herbal drug aren’t sure which substance in the plant is the active ingredient, or how much active ingredient their herbal product delivers. Even when the active ingredient is known, the amount of it can vary widely — as much as 10,000-fold — between products made by different manufacturers.
Because herbal drugs are not regulated as drugs by the FDA, they don’t have to undergo the rigorous testing that conventional drugs must undergo before they are marketed. The manufacturers of conventional drugs must prove the safety and efficacy of their products to the FDA before the FDA approves their use. This proof comes in the form of extensive scientific studies of the drug in animals and in people. With herbal drugs, the situation is reversed: Because herbals are classified as foods, the FDA bears the burden of having to prove an herbal product is unsafe before the agency can take it off the market or restrict its use.
The controversy over herbals
The increasing use of herbal drugs in the United States and Europe during the last decades of the twentieth century has generated considerable controversy. Opponents of herbal drugs point to the lack of conclusive scientific evidence that these substances are safe and effective. They warn about the lack of standards in manufacturing that have led to toxic and sometimes fatal side effects and adverse reactions, and they call for more strict regulation of their sale and use. Proponents argue that herbal remedies have been around for thousands of years and so have stood the test of time, and they point to the growing number of scientific studies that seem to indicate that some herbal medicines work. Both sides call for more research to determine which herbal are actually effective and which may be ineffective or even dangerous.
A brief history of herbal medicines
People have long recognized the healing properties of certain plants. Herbal drugs have likely been around as long as humans have. Medicinal herbs were found on the body of an “ice man” frozen in the Swiss Alps for more than 5,000 years. Scientists think the man used these herbs to treat an intestinal disorder.
Many herbal medicines have an ancient history. The ginkgo tree has long been cultivated for medical use in China and Japan, where some of these hardy trees are over 1,000 years old. Chinese herbalists made tea from ginkgo seeds and prescribed the drink for many problems, including memory loss and asthma. In the 1700s, the tree was brought to Europe from China. In the 1950s, the Dr. Willmar Schwabe Company of Germany investigated the properties of the ginkgo leaf for possible medical use, and by 1970, ginkgo became one of the most widely prescribed herbals for dementia and for a type of weakness and pain in the limbs called intermittent claudication. In 1997, the Journal of the American Medical Association (JAMA) published a study indicating ginkgo might be useful in treating Alzheimer’s disease, sparking interest in the United States.
Before Europeans arrived in America, echinacea was a popular herbal drug among Native Americans, who used it to treat respiratory infections, inflammation of the eyes, toothache, and snakebite. European colonists quickly adopted the herb. In the nineteenth century, European Americans used echinacea as a “blood purifier,” believing that it cleared the blood of disease-causing toxins. Europeans used echinacea to treat diseases such as eczema, veneral diseases, lymphangitis (swelling of the lymph vessels), and sepsis (infection of the blood with microorganisms).
Many of the herbal drugs used in the United Sates and Europe are derived from traditional Chinese medicine and Ayurvedic medicine in India. These traditions are thousands of years old, and they rely heavily on plant-based prescriptions to treat various illnesses. Many other herbal drugs are folk remedies from other cultures. Historians of medicine note that every culture has its own tradition of folk medicine: treatments or cures widely believed to be effective, based on information gathered from trial and error on the curative properties of plants and passed down through generations.
Before the advent of modern and synthetic drugs in the nineteenth century, the United States had its own folk medicine tradition. In colonial times, people often relied on homemade botanical remedies based on the folk traditions of their original countries. People also learned about the healing properties of local plants from Native Americans.
As more Europeans came to the Americas and settlements grew into cities, some herbal remedies transformed into “patent medicines,” which people could buy at the local store or from traveling salesmen. Packaged in fancy bottles and laced with generous amounts of alcohol, these medicines were of doubtful value, although their labels claimed they could cure everything from the common cold to cancer. One manufacturer of such medicines was H. C. F. Meyer, who in the late 1800s sold combinations of echinacea and other herbs. His outlandish, exaggerated, and poorly written labels helped define the “snake oil salesman” as an American icon.
From herbs to conventional drugs
In the 1800s, doctors, pharmacists, and scientists began to examine herbal remedies more closely. They began to identify the active ingredients in medicinal plants and to isolate and purify those substances. For example, the French pharmacist H. Leroux purified the drug salicin, the precursor of aspirin, from the bark of the willow tree in 1829.
The 1800s saw the transformation of many herbal remedies into conventional drugs. The story about how one herb, foxglove {Digitalis purpurea), was transformed into the modern-day cardiac drug digoxin, provides a good example.
In the 1700s, the condition known as dropsy was a common cause of death. (In the twenty-first century, doctors call dropsy congestive heart failure.) Dropsy occurs when the heart is too weak to keep all of the blood moving through the body. The blood accumulates in blood vessels and eventually seeps into surrounding tissues. Dropsy sufferers begin to swell with the excess fluid, and their arms and legs puff up so that they cannot move. Oftentimes, fluid fills the lung cavities and makes it impossible to breathe. Dropsy victims actually drown in their own bodily fluid.
In England, the folk remedy for dropsy was an herbal decoction, or “soup,” made from boiling about 20 different plants, including the herb foxglove. In the late 1700s, the English doctor and botanist William Withering, practicing in Stafford, examined this herbal remedy more closely. He recognized that the folk remedy worked, and he systematically tested each plant ingredient on his dropsy patients until he found the one that improved heart function — the leaf of the foxglove plant, also known as digitalis leaf.
Although he had discovered the medicinal properties of foxglove, Withering ran into a big problem: dosage. As he began to treat patients with a decoction of foxglove, he found that the boundary between an effective dose and a fatally poisonous one was dangerously slim. One of Withering’s first patients recovered after just a few doses. But another of Withering’s patients almost died from the effects of foxglove overdose — continuous vomiting and diarrhea. The dosage problem was complicated by the fact that the foxglove plant varied in potency from plant to plant and in different seasons. Withering would have to use three times as many leaves for his decoction in winter than in summer, when the plant bloomed.
In 1775, Withering began 10 years of experiments with foxglove. He gave dropsy patients small doses of the herb to start with, then gradually increased the dosage until the vomiting and diarrhea started. When that happened, he decreased the dose a little until the side effects disappeared but the beneficial effect on the heart remained. In this way, he was able to roughly determine the correct dosage. In 1785, he published a famous book on the properties of the foxglove plant, An Account of the Foxglove and Some of Its Medical Uses. The medical community recognized foxglove as a remedy for congestive heart failure until well into the twentieth century.
However, in the 1800s efforts were under way to purify the active ingredients from herbs and do away with the plant altogether. In 1804, the German pharmacist F.W. Serturner discovered how to isolate the chemical morphine from the poppy plant (Papaver somniferum). In 1870, the French researcher C.A. Natvelle used a similar process to purify a substance he called digitalin from the foxglove leaf. This purified substance became the conventional cardiac drugs digoxin and digitoxin.
In the late 1800s and early 1900s, advances in chemistry allowed scientists to further modify the drugs derived from plants to reduce their side effects. Chemists were also able to synthesize in the laboratory entirely new drugs with new beneficial properties. Eventually, it became cheaper and easier to synthesize the substances once derived from plants, rather than extract them from herbs themselves.
As modern, scientific medicine offered a growing number of effective drugs, interest in herbal remedies declined. The first edition of the United States Pharmacopoeia, a drug compendium published in 1820, listed about 200 plants recognized as drugs. These included hops (Humulus lupulus), licorice (Glycyrrhiza glabra), peppermint (Mentha piperita), senna (Cassia senna), and valerian root (Valeriana offtcinalis). But by 1936, the Pharmacopoeia listed on only 79 herbal drugs.
In the 1960s, however, a popular interest in alternative and complementary medicine sprang up in the United States and Europe. This growing interest in alternative medicine, which includes use of herbal drugs, has continued into the twenty-first century. Historians, public health experts, and cultural commentators are not sure why alternative medicine has become so popular, but they point to several factors that likely influenced this cultural shift.
First, the cost of health care has been rising, and people have grown dissatisfied with managed care, which has resulted in people spending less time with their doctors. Second, people have been concerned about the safety of synthetic drugs, especially after the tragedy, beginning in Europe, of birth defects caused by the drug thalidomide. Third, many people have conditions for which conventional medicine has produced no satisfactory cure, such as certain cancers, back pain, and arthritis. Disillusioned with scientific medicine and desperate for relief, these people have turned to alternative therapies such as herbal drugs. Finally, the cultural emphasis on health and wellness, self-reliance, and a renewed focus on all things “natural,” has probably led to the increased use of herbal drugs. Kenneth Shine, president of the U.S. Institute of Medicine, has commented that the easy availability of information about herbal drugs on the Internet probably has contributed their increased use.

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