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.