Diet pill

Diet pills/Debra Henn and Deborah DeEugenio. p. cm.—(Drugs, the straight facts)... 

With the high prevalence and steady increase in overweight and obesity in the United States comes a steady increase in the use of various diet supplements, including both nonprescription and prescription diet pills. 

The question of when and how diet pills should be used will be examined in later chapters. Overall, in carefully selected... 

The National Institutes of Health (NIH) has established guidelines on the use of diet pills. These guidelines are used by health-care practitioners both within and outside the United States. The information contained in these guidelines helps to determine who should and should not use weight loss medications. This is important because people who use diet pills inappropriately risk potentially devastating effects on their health. 

Diet pills work by affecting the body processes that cause weight gain. Diet pills work to cause weight loss in one of three main ways ... 

Side effects associated with this type of diet pill often occur because, in causing the body to burn more calories, the pills speed up many body processes—possibly to a level that becomes dangerous. Examples are increased blood pressure and heart rate, which can lead to heart problems over time. Other side effects include nervousness and insomnia. 

Many diet pills that work by increasing the number of calories burned have been developed. Most of these contain one or more of the three ingredients caffeine, phenylpropanolamine (PPA), and ephedrine. In the United States, PPA and ephedrine have been withdrawn from the market because they produce serious side effects, including heart attack and stroke. Caffeine, which is still found in many diet pills, will be further discussed in Chapter 6. 

Figure 3.1 Appetite is controlled by many body processes, as shown here. The arrows indicate things that increase and decrease hunger. All of these processes work by sending signals to the brain to indicate a feeling of hunger or satiety (fullness). Certain diet pills called appetite suppressants may work in the same way as some of these body processes, by sending signals to the brain that indicate satiety and say stop eating ...

Figure 3.2 Normally, when the stomach is full it sends a signal to the brain telling the body to stop eating. This message is carried by neurotransmitters (chemical messengers in the brain) to the hunger center in the hypothalamus (a part of the brain). Examples of neurotransmitters that carry this message are norepinephrine, serotonin, and dopamine. Many diet pills increase these same neurotransmitters that signal the brain that the stomach is full. These diet pills, called appetite suppressants, trick the brain into thinking the stomach is full and therefore decrease hunger.

Natural and herbal diet pills available in the United States today are considered dietary supplements and are not subject to FDA review prior to being sold. Although these agents may have drug-like activity in the body, they do not need to be proven safe or effective like conventional drugs do. Unlike conventional drugs, natural and herbal diet pills can only be withdrawn from the market when they are proven to be dangerous. As a result, many herbal products reach the market without any scientific evidence that they are safe or effective. These products are discussed in more detail in Chapter 6. 

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