Weight loss medications
Orlistat
Orlistat, brand named Xenical, is a medicine that has been shown in randomised, clinical trials to be effective in assisting and maintaining weight loss. It is now available from pharmacists without a prescription. It should only be used by people who are obese, or who are overweight and at risk of a heart attack because of high cholesterol or a co-existing disease such as diabetes or heart disease. It should not be used during pregnancy.
Orlistat works locally in the stomach and is not absorbed into the bloodstream. It limits fat breakdown in the gut so that one-third less fat is absorbed. The undigested fat passes through the gut and is excreted in the faeces.
If too much fat is eaten, the side effects of orlistat are an oily rectal leakage and oily, fatty bowel motions, often accompanied by increased urgency to empty the bowels. These adverse effects usually provide an incentive for people to keep the fat content of their diet low, which helps change eating habits.
Sibutramine
Sibutramine, brand named Reductil, is a serotonin and noradrenaline reuptake inhibitor, which means that it works by affecting brain chemistry.
The once-daily tablet works in 2 ways: it increases your feeling of satiety, so that your brain thinks you're full after eating only a small amount of food; and it helps prevent the normal slowing of your metabolism when you lose weight.
Studies have shown that Reductil plus diet and exercise can help overweight and obese people achieve and maintain weight loss. Potential side effects of Reductil include raised blood pressure and an increased heart rate in some people.
Phentermine
Phentermine, brand named Duromine, is a centrally acting appetite suppressant. These medicines require very close monitoring so your doctor should reassess your condition every 3 months or less.
Duromine should not be used in people with high blood pressure, an overactive thyroid gland, epilepsy, a history of a psychiatric disorder, or a history of drug or alcohol abuse or dependency. This medication is also not suitable for pregnant women.
Adverse effects include dry mouth, headaches, insomnia, restlessness, nervousness, agitation, irregular heartbeat and, rarely, psychosis and hallucinations.
Fenfluramine (no longer available)
Fenfluramine was previously used as a weight loss medication, both on its own and in combination with phentermine. The combination medication, known as fen-phen, was especially popular in the United States. Medications containing fenfluramine were withdrawn from the market in 1997 because of concerns that they caused heart valve damage.
Diethylpropion hydrochloride (no longer available)
Diethylpropion hydrochloride, brand named Tenuate or Tenuate Dospan, is another prescription medication that was previously used in conjunction with calorie restriction, on a short-term basis only, in obese people. It has been withdrawn from the market.
Side effects included an irregular heartbeat, high blood pressure, dry mouth, nausea, abdominal discomfort, seizures and nervousness, and there were some reports of people becoming psychologically dependent on this drug.
Future possibilities: leptin supplements and tesofensine
Leptin is a naturally-occurring hormone that is involved in regulating weight gain. There are ongoing clinical trials investigating whether medicines containing leptin (or similar substances) may be useful as weight loss medications.
Tesofensine — a noradrenaline, dopamine and serotonin reuptake inhibitor — is another medicine that works by affecting brain chemistry to reduce your appetite. It is currently undergoing trials overseas and showing promise as an effective weight loss medicine.
Herbal and alternative treatments
There are many non-prescription medicines and herbal remedies available that reportedly help with weight loss. Ask your doctor before trying these treatments, because most have not been tested in the same way as prescription medications, and their safety and effectiveness are often unproven.
Remember, weight loss medications only work when they are used in combination with lifestyle modifications, such as increased exercise and decreased food intake.
Last Reviewed: 09 December 2008
Sponsored links
