15 Drugs We Didn’t Discover Were Harmful Until It Was Too Late

5 minute read

By Christopher Brown

The scientific method is built on a foundation of trial and error. Scientists test drugs to manage hidden side effects. But sometimes we discover the danger too late. Fortunately, you can learn about dangerous medications with a search online.

The history of prescription pills is littered with a laundry list of drugs that were once considered useful. That is, until they weren’t. Let’s take a look at 15 dangerous drugs that made it to America’s medicine cabinet.


If you’ve ever popped some corn and enjoyed a period piece about drugs and debauchery in the 70 s and 80s (Wolf on Wall Street, Almost Famous, etc.), then this one may sound familiar. Quaaludes were prescribed for over two decades to help induce sleep. But it didn’t take long before news of the drug’s recreational properties began to spread. Common side effects include mania, seizures, vomiting convulsions, and even death. In the U.S., it’s considered a Schedule 1 drug alongside heroin, marijuana, and LSD.


Sometimes it takes much more than a glass of warm milk to keep the heartburn at bay. Doctors began prescribing Propulsid in 1993 for severe nighttime heartburn and did so for nearly 7 years. Over the course of those 7 years, more than 270 cases of serious cardiac arrhythmias including 70 related deaths were reported. Propulsid is officially banned for use on humans but is still manufactured for animal use as of this writing.


Cylert was a stimulant designed back in 1975 to treat Attention Deficit Disorder and ADHD. It was pulled off of the shelf in March of 2005. Why was it discontinued? Well, that answer depends entirely on who you ask. If you ask its manufacturer, they’d tell you that they pulled the plug due to declining sales. But multiple lawsuits claim that Cylert is responsible for multiple fatal cases of liver toxicity.

Darvon and Darvocet

Darvon and Darvocet used to be a medicine cabinet staple. This opioid pain reliever hit the pharmacy shelves in 1955. It was promoted to relieve mild pain and was prescribed fairly regularly. And then the dominos began to fall.

First the UK banned it. Then Europe followed suit. Lagging nearly 6 years behind the others, the U.S. finally banned it. Why you ask? You see, Darvon and Darvocet have been linked to more than 2000 heart-related deaths.


Ahhh the 1980s. The days of big dreams, big hair, and gigantic mobile phones. Back in 1982, pharma company Hoffman-La Roche rolled out Accutane as a cure-all for acne patients. It worked, too. Showing significant acne reduction in 80% of users. Sadly, the drug’s side-effect list showed a few too many blemishes. It was later discovered that Accutane increased the risk of birth defects, miscarriages, and premature births when used by pregnant women. It was also linked to inflammatory bowel disease and suicidal tendencies.


Trasylol is a surgeon’s best friend. Rather, it used to be. Up until the point it was phased out back in 2008, it helped reduce blood loss during surgery for close to 50 years. Though it may have shaved a few rolls of quarters on the hospital’s laundry bill, it cost them a load of lives. Trasylol was banned by the FDA due to side effects that included serious kidney damage, congestive heart failure, strokes, and an increased chance of death.


This one goes by two different names. You can call it what you want, but I call it bad news. Ergamisol’s run lasted 11 years (1989 to 2000), and it was used to combat worm infestation, colon and breast cancers, and rheumatoid arthritis. Eventually, it was discovered to dramatically lower the patient’s white blood cell count in a few different ways, which caused dangerous blood clots in the patient’s blood vessels.

But don’t sweat it out too much. If you’re looking to get your hands on some Ergamisol, just hit up the shadiest street corner in your neighborhood. Some drug dealers have been cutting their cocaine with it to increase its euphoric qualities.


Patients suffering from Irritable Bowel Syndrome and Chronic Idiopathic Constipation used to be prescribed Zelnorm. That is until dramatic reports of dangerous side effects began rolling in. It turns out that Zelnorm actually increased the chance of heart attack, stroke, and heart and chest pain.


Patients on the quest for six pack abs bit off more than they could chew with the appetite suppressant Pondimin. As many as 30% of patients reported abnormal echocardiograms, 33 others developed a rare valvular disease, and 66 more reported heart valve disease. Though it’s no longer relied upon as a weight loss aid, it is still used recreationally as a hallucinogenic.


All it took was one year. Pain killer Duract was banned by the FDA after it was deemed responsible for 4 deaths, 8 patients who required liver transplants, and 12 more with severe liver damage. The fallout led to severe criticisms of the FDA’s fast-track approval process for prescription drugs and for good reason. 2.5 million patients had been prescribed Duract in less than a year. It’s a small wonder that the damage wasn’t any worse.


Hismanal was ripped off U.S. store shelves back in 1990. Before that, it was used to treat allergies, sneezing, runny noses, and hives. After a while though, it was discovered to do a whole lot more. Patients began noticing and reporting irregular heartbeats. The cause? Hismanal use was shown to slow the heart’s potassium channels causing Long QT Syndrome and Torsades de Pointes.


DES, or Diethylstilbestrol, hit store shelves back in 1940. It was a synthetic estrogen tablet that was believed to prevent miscarriage, premature labor, and a whole host of other pregnancy complications. Despite multiple studies showing that it was ineffective, it stayed on the shelves until 1971.

What happened in 1971? Well, alarm bells began ringing when mothers reported cancer, birth defects, and an increase in fertility and pregnancy complications. Even in early menopause. Yikes!


This over the counter painkiller killed a lot more than pain. In fact, the anti-inflammatory Vioxx was linked to nearly 30,000 heart attacks or cardiac arrests in a span of a few years (1999 to 2003). What’s worse, the drug’s manufacturer got caught withholding information regarding the drug’s dangers from doctors and patients for 5 years.


Baycol made headlines for all of the wrong reasons back in August of 2001. Bayer A.G.’s popular cholesterol buster lasted just 3 years before it was banned by the FDA. After it was all said and done, Baycol was linked to 52 deaths worldwide and over 385 non-fatal, kidney-related illnesses.


PTZ was used alongside electro-shock therapy to battle depression, schizophrenia, and a whole host of other psychiatric conditions. It was used a very, very long time, too.48 years, in fact. Which is truly horrifying when you consider the damage that it inflicted. Uncontrollable seizures, pulled muscles, fractured bones and spine fractures in as many as 42% of patients.

Christopher Brown