What are the Risks of Diet Pills?

People often turn to their physician to help them lose weight because it is so difficult. Americans spend billions of dollars every year attempting to lose weight, but their efforts are largely unsuccessful. Some doctors recommend the most natural and difficult path to weight loss, which is to reduce the number of calories consumed and ramp up exercise – and I talk about this method later on in the chapter. However, many patients have tried diets, and want something a bit more powerful to curb their appetite so they eat less, or something that will help them curb cravings and a psychological obsession with food. And these people will keep going to doctors until they find one willing to write a prescription for a diet drug – normally people do not have to search for such a doctor for very long. Alternatively, they will pick up some Ma Huang or another dietary supplement at the drug store, lured by the promise of near magical weight loss.

However, diet drugs generally have not been shown to help people reach or sustain their weight loss goal. Long-term use of diet drugs is associated with some dangers, most importantly the risk of heart attack or other cardiovascular event (even in young people). Another worrisome consequence of diet pills is primary pulmonary hypertension (PPH), a disorder that is typically of unknown cause that is associated with an increase in the pressure of the arteries in the lungs. The primary manifestation of PPH is breathing problems with exercise. The end result of PPH in the absence of a lung transplant is usually death. There is a 6-fold increase in risk of PPH with diet pills, including dexfenfluramine, fenfluramine, diethylpropion, clobenzorek, fenproporek, and phemetrazine. Patient taking diet pills for more than 3 months face a 23-fold increased risk. Although PPH is rare, so that the absolute risk of developing this disorder remains small, the certain lethality of it when it occurs should be cause for concern. At this point we can say that any diet pill that actually affects appetite (i.e. those affecting sympathetic function) should be considered risky.best phentermine otc alternatives

There are other life threatening side effects with diet pills, notably the dangerous effects of “fen-phen” (fenfluramine-phentermine) on the heart. Although the combination of these pills was never approved by the FDA, by 1996 over 18 million prescriptions a year were being written for this combination of pills as a weight loss treatment. Ultrasound examinations of the heart showed abnormalities of the heart valves in 24 women, five of whom required cardiac surgery for valve repair. This discovery led to the withdrawal of fen-phen from the market.

One of the most commonly prescribed medications for obesity, sibutramine (Meridia), acts on receptors in the brain that take up the neurotransmitters dopamine, norepinephrine, and serotonin back into the neuron. These neurotransmitters are involved in mood as well as appetite regulation. By blocking the reuptake of these neurotransmitters into the neuron, they increase the amount of neurotransmitter that is available in the space between the neurons (the synapse) and therefore increase the effects of these neurotransmitters. It is by this effect that Meridia is felt to have its weight loss properties, although the exact mechanism is not completely understood.

Meridia leads to a 4.45 kg (9 lb.) weight loss after 12 months of treatment (Li et al 2005). Some studies showed up to a 10 kg (22 lb) weight loss with Meridia (Godoy-Matos et al 2005). Unfortunately, weight returns to pre-treatment levels once Meridia is discontinued. Also, multiple studies have not shown evidence that Meridia (or any other weight loss drug for that matter) reduces obesity related death or disease, like heart disease, stroke, and hypertension.

The most common side effect of the drug is palpitations but it also causes increased blood pressure and stroke. Forty-nine cardiac deaths related to Meridia have been reported to the FDA. Administration to pregnant women can lead to fetal abnormalities. This has led to calls for Meridia to be removed from the market.Best Phentermine

Orlistat (Xenical) is another drug approved for the treatment of obesity. Orlistat inhibits the lipase enzyme, preventing digestion and absorption of some fats. Orlistat treatment results in 6 pound weight loss that persists for as long as treatment continues (Torgerson et al 2004). 91% of patients get gastrointestinal side effects, versus 65% on placebo. Diarrhea is very common, with less commonly flatulence, bloating, and dyspepsia. Orlistat inhibits absorption of fat-soluble vitamins (A, D, E, K), and may lead to vitamin deficiency, so you should take a vitamin if you are on this drug. Recently a low dose version of orlistat called Alli (pronounced like “ally”) has been approved for over the counter use in conjunction with a diet and exercise program.

The bottom line is that diet pills have not been shown to result in sustainable weight loss, and they have significant risks which could be fatal. Therefore I do not recommend their use. The best plan is a sustained change in diet and exercise.