#2-1. History of anti-obesity drugs II

In the previous article, we covered the brief history of anti-obesity drugs up to the 1950s. Here, we will glance over the 50 years of anti-obesity drugs up to the 2000s. This is to provide a sweeping view of how some popular drugs came into being and how some other ones were withdrawn. Each drug will be covered in greater detail in later articles.

In the last article, we talked about thyroid hormones used since the early 1900s and 2,3 DNP with fatal side effects. We also talked about amphetamine being used to treat obesity in the 1950s, when its toxic effects as a narcotic were yet to be recognized.

Amphetamine’s danger and addictive nature became known and it was soon withdrawn from the market. Amphetamine-like chemical derivatives were later developed for use as anti-obesity medication.

1. Phentermine, Phendimetrazine, Diethylpropion

These three drugs appeared around 1959 and are still the most commonly used appetite suppressants. We will take a look at each of them in greater depth later as they have similar time of introduction and pharmacological mechanisms. This article will provide a brief introduction.

Image 1. Chemical formula of amphetamine.

As shown in the chemical formulae of <Image 1>, these three drugs are amphetamine-derivatives. The habit forming nature of amphetamine is due to the strong dopaminergic effect. These three drugs have powerful action on norepinephrine, a neurotransmitter, to curb appetite. They have a mild dopaminergic action and are categorized as antipsychotics.

The reason behind their long-term popularity of over 50 years is the potent appetite suppression. However, the effect does not last and wanes after a certain period of exposure. Controversy continues over these drugs in various countries around the world. They are widely used in the US, Japan, China, and Korea, however, the recent trends in Europe are moving toward banning them since the early 2000s.

2. Rainbow Pills

In the 1950s and 60s when the FDA regulations were relatively less strict, several effective drugs were combined in a single formulation of anti-obesity medication. Digitalis, laxatives, thyroid hormones, diuretics, amphetamines and barbiturate, etc. were combined for this purpose. As you can imagine from just seeing the list of the drugs, this method was soon banned due to various serious side effects.