1st frostbite drug approved by FDA after successful clinical trial

The U.S. Food and Drug Administration (FDA) has approved the first drug to treat severe frostbite, the agency announced Feb. 14.

The drug, called iloprost, opens up blood vessels and prevents blood clotting in frostbitten patients. Following positive results in a small clinical trial, the drug has now been approved for use, under the brand name Aurlumyn, to treat severe frostbite in adults and reduce the need for finger or toe amputation.  

Severe frostbite occurs when parts of the body — usually the extremities, such as the nose, ears, fingers and toes — freeze after exposure to temperatures below 32 degrees Fahrenheit (0 degrees Celsius). When the tissue freezes, it reduces blood flow to the area, depriving tissues of oxygen and causing them to die. Blood clots can also form, further slowing down the flow of blood. Often, the only option is to amputate the region. 

The condition is rare in the U.S. — only 1 in 100,000 people are estimated to have experienced a severe frostbite injury between 2016 and 2018. However, it can have life-long consequences. 

Related: How does a person freeze to death?

"This approval provides patients with the first-ever treatment option for severe frostbite," Dr. Norman Stockbridge, director of the Division of Cardiology and Nephrology in the FDA's Center for Drug Evaluation and Research, said in the announcement Feb. 14.   

"Having this new option provides physicians with a tool that will help prevent the life changing amputation of one's frostbitten fingers or toes," he said. 

An early sign of frostbite is a loss of feeling and color in the skin, which may turn white or grayish-yellow or feel "unusually firm or waxy," according to the Centers for Disease Control and Prevention (CDC.) The mildest form of frostbite, known as "frostnip," only causes temporary skin damage and occurs when someone experiences pins and needles or throbbing in the affected area. It can be treated by gradually rewarming the skin indoors or by soaking it in warm water at around 105 to 110 F (40 to 43 C). 

However, people with more severe types of frostbite, when the skin feels hard and frozen, must seek medical attention, according to the Mayo Clinic.

In the past, doctors have used other clot-reducing drugs to try to save people's toes and fingers that have succumbed to frostbite, however these come with a high risk of bleeding or are only effective within 24 hours of the injury developing, Dr. Peter Hackett, a professor of medicine at the University of Colorado Anschutz Medical Campus, who was not involved in the trial, told CNN. 

However, iloprost, which was originally approved by the FDA in 2004 to treat pulmonary arterial hypertension, or high blood pressure in the lungs, doesn't carry this bleeding risk and can be used up to three days after injury, Hackett said. The drug has been used to treat severe frostbite for years in other countries, including in Canada and Europe, he told the news agency. 

The recent FDA decision comes after the conclusion of a clinical trial, in which 47 adults with severe frostbite were given either six hours of daily intravenous injections of iloprost and no other medications, a mix of iloprost and other medications, or only other medications. 

The trial found that no patients who received only iloprost required an amputation after a week, while 19% who received iloprost and other unapproved frostbite medications needed amputation, and 69% of patients who only received other medications needed amputation. 

This article is for informational purposes only and is not meant to offer medical advice.

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