A product called "Neptune's Fix," which is sold at convenience stores, contains a potentially dangerous substance nicknamed "gas station heroin." It's been tied to a cluster of severe side effects — including seizure and cardiac arrest — in New Jersey, according to a report from the Centers for Disease Control and Prevention (CDC).
Gas station heroin, formally known as tianeptine, isn't approved by the U.S. Food and Drug Administration (FDA) for any medical uses, but in some countries, it's been cleared as a treatment for depression or anxiety. It's considered an "atypical" antidepressant, in that it alters the activity of a variety of chemical messengers in the brain and, notably, activates opioid receptors.
Although the drug is not approved in the U.S., illegal products containing tianeptine can be found online and at gas stations and convenience stores in the country. These are often marketed as being able to improve brain function and treat anxiety, depression, pain and opioid use disorder, among other conditions, the FDA notes.
The products are dangerous because they contain unknown doses of the drug that can be higher than those that would be prescribed in countries where tianeptine is legal. These products can also contain additional drugs not listed on their labels.
The FDA issued a warning about the so-called elixir shot Neptune's Fix in January, following an initial warning in November. Investigators described the cluster of severe illnesses tied to the product on Thursday (Feb. 1) in the CDC's Morbidity and Mortality Weekly Report.
The unusual spike in tianeptine exposures occurred in the state between June and November 2023. It affected 17 people, 14 of whom reported using Neptune's Fix.
The people affected developed a variety of severe symptoms, including cardiac arrest, seizures and rapid heart rate. Many showed abnormal electrical activity in the heart that indicated an increased risk of dangerous heart rhythms that could lead to cardiac arrest. Thirteen of the 17 people were admitted to an intensive care unit, and seven required breathing support, but no one died.
In general, misusing tianeptine by itself or with other drugs can lead to confusion, rapid heart rate, high blood pressure, nausea, vomiting, slowed or stopped breathing, coma and death, the FDA noted.
Scientists obtained samples of Neptune's Fix connected to the cases and found that all of their bottles were labeled as containing tianeptine and kavain, a substance made from kava root (Piper methysticum) and reported to promote relaxation.
However, an analysis of the elixirs revealed that some contained drugs that were not listed on their labels. These included THC and CBD, the high-inducing and nonpsychoactive ingredients in cannabis, respectively, and the synthetic cannabinoids MDMB-4en-PINACA and ADB-4en-PINACA.
The first of these so-called designer cannabinoids is thought to potentially pose health risks, including poisoning, but its safety profile is poorly understood, the CDC report notes. However, test-tube studies suggest MDMB-4en-PINACA is very potent, and it's also possible that chemicals used to manufacture the drug pose a risk.
"It is important for members of the public and health care professionals to be aware that tianeptine is an unregulated drug sold under several product names (e.g., Neptune's Fix, Pegasus, and Zaza) that can produce adverse effects and dependence," the report closes. "Readily purchased tianeptine products might be adulterated with SCRAs [synthetic cannabinoids] or other drugs and can produce severe clinical effects."
The manufacturer of Neptune's Fix products, Neptune Resources LLC, has agreed to voluntarily recall all of its lots of Neptune's Fix Elixir, Neptune's Fix Extra Strength Elixir and Neptune's Fix Tablets, the FDA said. The agency's warning doesn't note what other consequences the company may face.
Consumers, distributors and retailers with the recalled products should throw them away or return them to the place of purchase.
This article is for informational purposes only and is not meant to offer medical advice.
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Nicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work.