What are the drugs used for weight loss.
Drugs used for weight loss are generally called anorexiants. All the drugs are potentially effective when used appropriately and with additional weight loss measures, including exercise and behavioral modification. The long-term effects of most of these medications have not been established. Most lose their effectiveness over time, thus requiring increased dosage, and they can be addictive and dangerous. None of these drugs deals with the underlying problems that may be causing obesity. Unless specifically instructed by a doctor, people should use non-drug methods for losing weight. Except under rare circumstances, pregnant or nursing women should never take diet medications of any sort, including herbal and over-the-counter remedies. Over-the-Counter Drugs and Herbal Remedies People must be cautious when using any weight-loss medications, including over-the counter diet pills and herbal or so-called natural remedies. The following are examples of some being sold for weight loss. Over-the-counter diet pills that contain phenylpropanolamine
(Acutrim, Dexatrim (no longer, learn
more)) effectively suppress appetite, but have been known to cause
severe high blood pressure and stroke if taken in doses of 75 mg or
higher in the immediate-release form. The FDA has moved to take such
products off the market. A number of over-the-counter remedies (Herbal Phen-Fen,
PhenTrim, Phen-Cal, Xenadrine) contain ephedrine, derived from the ephedra
(also known as Ma Huang) herb. Ephedrine is actually a component in
adrenaline and can cause a number of side effects, including infrequent
cases of severe effects (rapid heartbeat, high blood pressure, psychosis,
heart attacks and seizures). Pseudoephedrine, an ingredient commonly
found in many antihistamines, has similar effects and is sometimes used
by dieters. There is some evidence that cholecystokinin (CCK), a
protein derived from potatoes, may reduce appetite. A powder (Satietrol)
is available. Small studies on conjugated linoleic acid (CLA) suggest
that it may reduce body fat and insulin levels in type 2 diabetics.
Adverse side effects are frequent, however. Many so-called natural remedies are being promoted for
weight loss. Some can be dangerous and few have been tested. Chinese
remedies that contain Aristolochia, for example, have been banned by
the FDA after reports of cancer and kidney failure. Chitosan, a dietary
fiber from shellfish does prevent a little fat from being absorbed in
the intestine, but limited studies have not found that it contributes
to weight loss. Garcinia (also called mangosteen) is a tropical fruit
containing hydroxycitric acid, which is claimed to burn fat. Although
theoretically promising, to date no well-conducted study has reported
significant weight loss with the chemical. Many dietary herbal teas contain laxatives, which can
cause gastrointestinal distress, and, if overused, may lead to chronic
pain, constipation, and dependency. In rare cases, dehydration and death
have occurred. Some laxative substances found in teas include senna,
aloe, buckthorn, rhubarb root, cascara, and castor oil. Dietary remedies that list the ingredient plantain may contain digitalis, a powerful chemical that affects the heart. (This should not be confused with the harmless banana-like plant also called plantain.) Orlistat Orlistat (Xenical) can help about one third of obese patients with modest weight loss, and can assist in long term maintenance of weight loss. It reduces the body’s absorption of fat from foods, thereby reducing weight and cholesterol. Orlistat blocks the action of lipase, an enzyme in the intestine that breaks down fat. It does not increase serotonin but it makes it work effectively, and it is a stimulant. Studies have found that at the end of the first year orlistat users achieve an average of 5% to 10% drop in body weight. Studies are also reporting that the drug may delay or prevent the onset type 2 diabetes, improve cholesterol levels regardless of weight loss, and reduce blood pressure. (It should be noted that some people who take this drug experience an increase in blood pressure.) The drug can cause gastrointestinal problems and may interfere with absorption of the fat-soluble vitamins A, D, and E and other important nutrients. Sibutramine Sibutramine (Meridia) keeps two important brain chemicals -- serotonin and norepinephrine -- in balance, which helps to increase metabolism. It causes a feeling of fullness and increases energy levels. Studies indicate that sibutramine assists with weight loss and helps maintain it. Patients who discontinue the drug, however, report significant weight gain afterward. Some studies also report improved cholesterol and other lipid levels with the use of this drug. Common side effects include dry mouth, constipation, and insomnia. Of concern are reports of increases in heart rate and blood pressure, although on the positive side, two studies reported significant improvements in cholesterol levels. Experts believe sibutramine is probably safe, but the long-term effects are still unknown. People who have a history of high blood pressure, stroke, heart disease, or arrhythmias should not take this drug. People taking decongestants, bronchodilators (such as for asthma), monoamine oxidase inhibitors, or serotonin reuptake inhibitors should also avoid sibutramine. Serotonin-Releasing Anorexiants Serotonin-releasing anorexiants increase the availability of serotonin, a chemical in the brain that prevents depression and reduces calorie consumption. Unfortunately, the most popular of these drugs have very serious side effects, including development of abnormalities in the valves of the heart and, uncommonly, a potentially life-threatening condition called pulmonary hypertension. As a result, dexfenfluramine (Redux), fenfluramine (Pondimin), and the combination drug commonly called fen-phen, fenfluramine (Pondimin) have been pulled from the market. Studies report that changes may occur in patients taking the drugs for more than three months. To date, even in these patients, there do not seem to be serious complications. Taking the drugs for a short period (two to three months) appears to do no harm at all. Patients who were treated with Redux, Pondimin, or phen-fen for more than three months should have a thorough cardiovascular exam, including an echocardiogram. Many women who had valvular abnormalities had been taking multiples of the recommended dosages. Others were also on Prozac, an antidepressant that also increases serotonin and intensifies the effects of the diet drugs. Amphetamines The amphetamines dextroamphetamine (Dexedrine), methamphetamine (Desoxyn), and phenmetrazine (Pleudin) were used most often in the past but are no longer prescribed for weight loss. These drugs elevate mood and produce some modest weight loss over the short term, but present serious risks of addiction, agitation, and insomnia. Sympathomimetics Sympathomimetics are agents that act like the neurotransmitter norepinephrine (a stress hormone). Less addictive and possibly safer than amphetamines, these drugs still raise blood pressure. They are approved for short-term use and include phentermine (Ionamin, Adipex, Fastin), diethylpropion, mazindol (Mazanor, Sanorex), benzphetamine (Didrex), and phendimetrazine (Adipost, Botril, Melfiat, Plegine, Prelu-2, Statobex). Phentermine has been withdrawn from the UK market but not the US. Experimental Therapies Naltrexone. The drug naltrexone (Trexan) blocks the euphoria of drug abusers and is being tested for people who binge. Its effects have been promising. (The drug has no effect on people who do not binge.) It is, unfortunately, available only by injection. Leptin. Preliminary results from early studies on the use of daily injections of genetically engineered leptin are reporting weight loss among some genetically obese subjects. Higher doses may be needed for higher weights. The most common side effects were pain at the injection site and headache. There appear to be no significant adverse effects on major organs, including the heart, liver, kidney, central nervous system, or gastrointestinal tract. It also does not appear to affect insulin levels, a previous concern. Neuropeptide Y. Neuropeptide Y is a powerful appetite-stimulating chemical in the brain. Agents are being investigated that block this peptic. Accomplia The hot new diet drug in the news is the French drug called Accomplia Rimonabant. It was created to help people quit smoking and lose fat by blocking circuitry in the brain that gives the body cravings. The diet drug, rimonabant accomplia, which could be available in a year or two, is an appetite suppressant, but works by an entirely new approach by blocking the same primeval circuitry in the brain that gives pot-smokers the munchies. The French firm Sanofi-Synthelabo plans to seek U.S. approval to sell it under the brand Accomplia after more studies are finished next year. The following excellent article appears at webmd.com, the best website on the Internet.
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