Have you ever been happy to suddenly find money or chocolate while looking for a pen or other similar item in your bag? Such a happy and unexpected phenomenon that happens seemingly by accident and often occurs when we are looking for something else is called ‘Serendipity.’ The same case happens with researchers. No! They don’t find money or chocolate, but they find another drug instead of the one they are looking for.
Serendipitous discoveries are very interesting and meaningful. In this series of articles, we are going to share some amazing drug discoveries that happened in a serendipitous way.
The term "drug" or "medicine" refers to any substance (other than food) used to prevent, diagnose, treat, or relieve the symptoms of an unusual disease or condition. Serendipity is one of the major factors that plays an important role in drug discovery. Serendipitous discoveries are very interesting and meaningful. It reveals a very surprising, often exciting, and useful aspect of reality. The fact that is discovered is part of nature but remains hidden from us until a scientist uses proper methods to reveal it.
In this series of articles, we are going to share some amazing drug discoveries that happened in a serendipitous way. Serendipitous drug discoveries are often accidental, as the name suggests. However, nowadays, some scientists try to design their experiments in a way that increases the likelihood of serendipity. Most drug discoveries took years of research, but as these historical discoveries demonstrate, serendipity is often the key.
Sedatives ( also known as Tranquilizers or CNS depressants) are a group of drugs that slow down the brain. People use these drugs to calm down, relax, and sleep better.
A. Potassium Bromide
It has been widely used as a sedative in medicine since ancient times. It is the potassium salt of bromine, a chemical element, first isolated from the ashes of algae in 1826 by A.J. Balard, a pharmacist in Montpelier, France. In its natural form, bromine is too caustic to ingest. It is well tolerated as a potassium salt.
Thinking that bromine was a substitute for iodine, French doctors began to use potassium bromide for some diseases for which there was no specific therapeutic effect. In 1857, 31 years after bromine was isolated, Charles Lockock, a London-based intern, discovered the drug's antispasmodic and sedative effects. His discovery was one of the many strange examples of serendipity, where a completely wrong theory led to correct empirical results.
Lockock's motive was to control epilepsy, i.e., convulsions, by reducing the frequency of masturbation. The treatment was successful in terms of controlling the spasms. It also drew attention to the drug's sedative properties.
Potassium bromide and other inorganic bromide salts were widely used as anxiolytic sedatives and anticonvulsants during the second half of the 19th century. They were undoubtedly effective, although their relatively low therapeutic efficacy combined with high toxicity has practically banned their clinical use today.
Viagra, Pfizer's blockbuster erectile dysfunction drug, was launched in 1998. In 20 years, it has become so universal that, according to a Pfizer spokesperson, 62 million men worldwide have bought the drug.
Despite the drug's fame today, the scientists who discovered it weren't even looking for it. Pfizer originally developed the Sildenafil compound, or Viagra to treat hypertension (high blood pressure) and angina (chest pain due to heart disease). It was thought to widen blood vessels in the heart by blocking a certain protein called PDE-5. In the preclinical studies, it seemed to work quite well. So in the early 1990s, a phase I clinical trial was started to test whether people could tolerate this new compound.
Everything seemed to be going well, except for one strange thing that the men attending the trial did when the nurses came to check on them. They found many men lying on their stomachs. A very attentive nurse talked about this, saying that the men were so ashamed because they had an erection. It turned out that the vasodilation happened not in the heart, but in the penis (vasodilation is a part of the process leading to an erection).
Sildenafil worked, but in the wrong part of the body. Thus, the purported "virility pill" came into existence.
The US Food and Drug Administration approved Viagra for use in the treatment of erectile dysfunction in 1998. After ten years, experimenters began new clinical trials to see if it could work as a heart medicine as first intended. Indeed, in 2005, the FDA approved the same drug for a heart condition called pulmonary hypertension, which restricts blood flow to the lungs and affects both men and women.
Check out the next part of this series to learn more about other accidental drug discoveries...