Sibutramine hydrochloride monohydrate, brand name Meridia, is an FDA approved oral prescription medication used for the management of obesity and maintenance of weight loss and is known to work best when used in conjunction with a reduced-calorie diet and increased physical activity. Meridia works by affecting natural chemicals in the brain involved in regulating the appetite and allows them to act longer. The appetite control center in the brain is what is believed to regulate the amount of food eaten through feelings of hunger and fullness. Unlike many other appetite suppressant drugs, Meridia is not a releasing agent. It does not get inside the cells to boost the release of neurotransmitters, such as serotonin. Instead, as an uptake inhibitor, Meridia works outside the cells to stop these neurotransmitters from being reabsorbed and thereby allowing appetite control to last longer. In clinical trials of 6,000 individuals, Meridia produced clinically and statistically siginificant weight loss results. Meridia was studied among men and women, ages 18 to 65, and on average, patients achieved 5-10% reduction of baseline weight. If appetite control is necessary while on a ketogenic diet this drug might be a good addition. Most side effects associated with Meridia are mild and momentary in nature, including dry mouth, headache, constipation and insomnia. In some patients, Meridia substantially increases blood pressure. MERIDIA should be taken once a day without regard to meals. It will also be available in multiple doses (5, 10, and 15 mg), enabling physicians to individualize therapy for their patients. The recommended starting dose of MERIDIA is one 10 mg capsule per day. Patients with inadequate weight loss should be titrated to a 15 mg dose.

Orlistat (Xenical)

On May 24, 1999, a new diet drug that reduces fat absorption finally won approval from the Federal Drug Administration. It was only the second diet drug (after sibutramine) to receive FDA approval since 1997, when the administration banned the popular fen-phen combination after it was linked to several heart-related deaths. Orlistat, the first of a new class of drugs called lipase inhibitors, can decrease absorption of dietary fat in the gastrointestinal tract by about 30 percent, according to drug manufacturer Roche Laboratories. This would indicate it would not be an optimal choice for a ketogenic diet. The FDA approved it by prescription for the seriously obese only and not casual dieters who want to shed five or 10 pounds. The drug, trade-named Xenical, was tested over seven years on more than 4,000 patients and on average, 57 percent of patients treated with Xenical and 31 percent of placebo-treated patients lost at least 5 percent of their body weight. All patients in the studies received nutritional counseling as well. In January, the results of a two-year study on the effectiveness of Xenical were released in the Journal of the American Medical Association. The study, funded by the drug's manufacturer, found Xenical helped patients lose weight, but only about seven pounds more after two years than the patients who took a dummy pill. The JAMA study also showed Xenical was associated with a slight reduction in cholesterol, blood pressure and glucose. For those taking the drug, health authorities recommend a nutritionally balanced diet with no more than 30 percent of calories from fat. Xenical reduces absorption of some fat-soluble vitamins such as A, D, E, K and beta carotene, so users of the drug are advised to take dietary supplements. Side effects of Xenical include gas, diarrhea and intestinal cramping. Typically the more fat patients eat, the more effects they experience.