Clinical trials are set up to test the ability of a drug to make a change in a certain variable (e.g. can the drug lower blood pressure or lower pain?). Clinical trials undergo various phases of testing to understand the structure and function of a drug and how it interacts with other drugs. In most cases, drugs are researched and developed for a specific purpose. Sometimes, however, drugs are found by accident, or are used for different purposes than once intended. We take a look at some of these drug success stories below.
Benzodiazepines (BZDs) are core components of sedatives like Valium which have anti-anxiety, anti-convulsing and muscle-relaxing properties. BZDs were discovered by accident during testing for a chemical dye. Today BZDs are widely used to treat anxiety, seizures and alcohol dependence.
Warfarin was initially developed to terminate rodents. The compound has anticoagulant properties (i.e. it prevents blood from lumping together or clotting) which caused the animals to perish from internal bleeding. It was soon realized that if an appropriate dose was given to humans, it could be beneficial. Warfarin is now prescribed to prevent both the formation of clots in the blood as well as the potential for clots to break free from vessels and circulate in the blood. As a result, Warafin reduces the risk of a heart attack or stroke by preventing clots from lodging in vessels in the heart or brain. Warfarin gained popularity in the U.S after it was prescribed to President Eisenhower after his heart surgery in 1959.
Penicillin was discovered in 1928 by Dr. Alexander Fleming. The doctor accidentally left the lid off his petri dish (a shallow container scientists use to grow bacteria), allowing for the growth of mold. He discovered that bacteria near the blue mold (penicillium) were killed by an antibiotic produced by the mold. He named this antibiotic Penicillin. Penicillin went on to treat previously untreatable bacterial conditions such as syphilis.
This little blue pill that made Pfizer famous was initially developed for the treatment of pulmonary hypertension (high blood pressure in vessels near the lung). The drug would work by relaxing the muscles of the heart to decrease blood pressure. However, the drug also relaxed other muscles, resulting in an increased blood flow in certain areas of the male body. The rest, as they say, is history! Although sildenafil can be prescribed for the treatment of pulmonary hypertension, it is most widely used for its famous ‘side effect’.