How a medicine became a poison
In 1937, a U.S. drug company marketed a liquid version of sulfanilamide, an antibiotic used to treat infections. To make the medicine dissolve, the company’s chief chemist chose diethylene glycol, an industrial solvent, as its liquid carrier. A carrier is the substance that holds a drug in a form people can swallow. The solvent made the preparation taste sweet, but it was dangerously toxic when ingested.
Patients and families had no practical way to detect the danger from its taste or appearance. They took the medicine expecting treatment; instead, diethylene glycol damaged the kidneys and caused fatal poisoning, including among children. More than 100 people died.
The gap in the law
At the time, federal law generally required drug makers to show that a product was not falsely labeled before selling it. It did not require them to establish a medicine’s safety in advance. The new preparation could therefore reach patients without the kind of safety testing that might have exposed the solvent’s danger.
The deaths made that gap impossible to ignore. Congress passed the Federal Food, Drug, and Cosmetic Act of 1938, which required manufacturers to provide evidence of a drug’s safety before marketing it. The law did not guarantee that every medicine would be harmless, but it shifted the burden: companies had to assess safety before patients bore the risk.
A change in what “medicine” had to mean
The tragedy revealed that a drug’s active ingredient is only part of the product. Its solvent, flavoring, and other ingredients can also determine whether it is safe. A medicine could not be judged solely by whether its intended drug might help; the whole preparation had to be considered before it went on sale. The sweet taste that concealed the poison became a stark reminder that patients cannot be expected to taste-test their way to safety.
