The 'Accidental' Discoveries of 8 of the World's Most Revolutionary Drugs and Medicines

By | July 11, 2017

Chlorambucil - Antileukemia Drug

Chlorambucil is an anti-leukemia drug first approved by the FDA in 1957. It's origin go all the way back to the use of mustard gas on World War I battlefields.

Many years after the war and under the looming threat of World War II, researchers at Yale University were looking into treatments for mustard gas poisoning when they noticed that soldiers exposed to the gas had unusually low white blood cell counts. This led to the discovery that nitrogen mustard–based compounds could be used to kill mutated and cancerous white blood cells and prevent further tumor division. More research led to the development of chlorambucil, which is still used to treat these types of cancers to this day.


The story of this drug's discovery started when scientists testing a new angina-prevention drug received reports of an unexpected effect from the volunteers. Male participants were experiencing more frequent erections. Further research indicated that it was indeed the angina medication causing this unexpected effect, and thus, the “little blue pill” was born.

Viagra was marketed as the first oral treatment for erectile dysfunction in 1998. Now, 20 years later since its discovery, it has become one of the most prescribed drugs in the world.


Botox was first used as a drug to prevent muscle spasms within the body, specifically for people suffering from eyelid or vocal cord spasms.

However, its usage around the eyes had some unexpected effects. The drug began to diminish wrinkles around the brow area of the face, which led to its use in cosmetic surgery to reduce facial wrinkles and to smooth skin. The rapid evolution of this treatment has led to Botox cosmetic surgery becoming one of the most popular medical treatments, with over seven million procedures in the US alone in 2016.

Smallpox Vaccination

In the late 18th century, Edward Jenner made remarkable contributions to the development of the smallpox vaccine.

Smallpox was one of the most feared diseases due to its high mortality rate and the extensive facial scarring inflicted on those who survived. Prior to Jenner, the only preventive measure was variolation (inoculation) using pustule material from someone who already had the disease. Variolation led to a less severe case but could still result in death.

However, in his small-town practice in rural England, Jenner noticed that milkmaids who caught the less serious cowpox would not catch smallpox. This idea of infection with a less harmful virus led to the development of the vaccination. (Vacca is Latin for “cow.”) The importance of developing the smallpox vaccine cannot be understated. In 1980, the World Health Organization declared this once-feared disease officially eradicated, making it the first disease to be wiped out on the face of the planet.


Although many people have heard of the chance discovery of penicillin by Alexander Fleming in 1928, very few know the story of Ernst Chain and Howard Florey, the men who developed penicillin into a drug. All three men shared the Nobel Prize in Medicine in 1945 for their work on penicillin.

While studying antibacterial substances at Oxford University in the 1930s, Chain, Florey, and their team began researching Fleming’s work on penicillin and devised a plan to mass-produce the penicillin mold to treat infections. The two duo's efforts did not go unnoticed by the US armed forces. During World War II, the military realized penicillin’s potential to treat battle wounds for infections and began mass-production of the drug for the D-day landings. Penicillin went on to save countless lives during the war and beyond.


More commonly marketed as Antabuse, disulfiram is used to reduce alcohol addiction. The drug reacts with the alcohol consumed to cause nausea and an increased heart rate. This is meant to be a deterrent for drinking.

Two Danish medical researchers, Jens Hald and Erik Jacobsen, originally tested this drug as an antiparasitic. Each decided to try small samples to establish the side effects. Later, at an after-work cocktail party, this turned out to be a big mistake.After the men consumed small amounts of alcohol, both rapidly became violently ill. This led them to conclude that the two events were connected and that their antiparasitic might have another use.


Cisplatin is used in the treatment of testicular cancers. In fact, it is estimated to cure up to 90 percent of cases of this type of cancer.The discovery of the drug’s anticancer properties by US chemist Barnett Rosenberg in the 1960s occurred mainly by chance. Rosenberg was testing a hypothesis based on the effect of strong electrical fields on E. coli when he noticed that it was able to prevent division of the bacteria’s cells.

Rosenberg discovered that the use of platinum electrodes caused this effect, not the electrical current. He had actually synthesized a chemical known as “Peyrone’s chloride” that was first isolated in the 1840s. But its use in the treatment of cancer had not yet been realized.Since this initial development in the 1960s, cisplatin has become one of the leading anticancer drugs worldwide.


During the 1920s, the northern US and Canada experienced an epidemic of dying cattle that were bleeding profusely. An investigation determined that the problem was caused by the cattle eating moldy silage made from sweet clover, and so the case was closed at that time.

Then, in the 1940s, Karl Link and his student Harold Campbell in Wisconsin isolated the compound responsible for the anticoagulant properties in sweet clover. This was developed into warfarin, which was licensed as a rat poison in 1948. It caused massive internal hemorrhaging in rats unfortunate enough to consume it.

Now, the most popular use of warfarin is in the prevention and treatment of diseases like stroke that are caused by blood clots. The drug was not licensed for use in humans until 1954 after a US military recruit’s failed suicide attempt showed that warfarin could be used in a nonfatal manner. Interestingly, one of the first recipients was then-President Dwight D. Eisenhower.

H/T Listverse