Four years ago, Maine made a mistake. Now, the U.S. Congress might repeat it.

Maine legalized the importation of foreign drugs in 2013, enabling residents to buy medicines from pharmacies in Canada, the United Kingdom, Australia and New Zealand. Lawmakers thought that those countries’ safety standards matched ours.

From Maine’s experience, this was not the case. Investigators discovered that pills imported from a Canadian pharmacy contained just 7 milligrams of the active ingredient. They were supposed to contain more than seven times that dosage.

The inferior product in question was a knock-off erectile dysfunction pill. Had it been insulin or a drug to treat cancer, the consequences could have been fatal.

Unfortunately, national officials are poised to repeat this mistake. Some in Washington want to open up the nation’s pharmaceutical market to foreign imports by consumers. They claim the added competition could bring down drug costs. But in reality, they’re opening the floodgates to dangerous counterfeit medicines.

Alarmingly, counterfeit drugs are saturating the world markets now more than ever. In 2011, investigators seized 2.4 million fake or illicit drugs. In 2015, the latest data available, investigators snatched 20.7 million such drugs, an upsurge of more than 760 percent. The adulterated drugs ranged from antibiotics to HIV medications.

There is a sizable market for drug counterfeiting. The World Customs Organization estimates that it’s a $200 billion business, with online sales accounting for $75 million of that figure. Cardiovascular and anti-infection drugs are among the most common fakes.

“These falsifiers are, in fact, murderers — they are causing death,” said the executive director of the North Carolina-based Gillings Global Gateway.

India’s Central Bureau of Investigations reasons that counterfeit drugs have killed more people than terrorists during the past four decades. Even modest reports put the number of fatalities worldwide around 100,000 annually. Graver estimates say that figure is closer to a million.

The FDA acknowledges the enormous perils posed by counterfeit drugs and has consequently curtailed imports of foreign medicines for more than a decade.

As early as 2003, a top FDA official cautioned Congress that while the agency could be reasonably confident about the authenticity of American-made drugs, it “cannot ensure the safety of drugs purchased from foreign sources.” Even drugs directly imported from supposedly “safe” countries, such as Canada or the United Kingdom, are at risk because they may have actually originated elsewhere, in a nation lacking rigorous protections.

The FDA’s vigilant policy has kept the United States drug supply chain “one of the safest in the word.” It’s important that it is kept that way.

Maine’s brief experiment quickly illustrated the risks that people will face if drug importation is legalized.

Dangerous drugs are no bargain at all. Across the globe, far too many patients have paid for cheap medicine with their lives.

Felicity Homsted, PharmD, BCPS, is the chief pharmacy officer for Penobscot Community Health Care in Bangor.

Felicity Homsted