The U.S. Food and Drug Administration has approved the first medication to treat severe frostbite in adults to reduce the risk of finger or toe amputation.
The treatment involves injections of the vasodilator iloprost, originally approved by the FDA in 2004 for the treatment of pulmonary arterial hypertension. In its new indication, the medication is being marketed under the name Aurlumyn.
“This approval provides patients with the first-ever treatment option for severe frostbite,” said Norman Stockbridge, M.D., Ph.D., director of the Division of Cardiology and Nephrology in the FDA’s Center for Drug Evaluation and Research, in a press release. “Having this new option provides physicians with a tool that will help prevent the life-changing amputation of one’s frostbitten fingers or toes.”
Frostbite can occur in several stages, ranging from mild frostbite that does not require medical intervention and does not cause permanent skin damage, to severe frostbite when both the skin and underlying tissue are frozen and blood flow is stopped, sometimes requiring amputation. In this indication, iloprost is used to increase blood flow to the affected areas and prevent blood from clotting.
Iloprost’s efficacy in treating severe frostbite was primarily established in an open-label, controlled trial (New England Journal of Medicine, Jan. 13, 2011; 364:189-190) that randomized 47 adults with severe frostbite, who all received intravenous aspirin and standard of care, into one of three treatment groups. One of these groups (Group 1) received intravenous iloprost for six hours daily for up to eight days. The two other groups received other medications that are unapproved for frostbite, given with iloprost (Group 2) or without iloprost (Group 3). The primary measure of efficacy was a bone scan obtained seven days after the initial frostbite that was used to predict the need for amputation of at least one finger or toe.
On day seven, findings from the bone scans that predicted a need for amputation were observed in 0% (0 of 16) of the patients receiving iloprost alone (Group 1) compared to 19% (3 of 16) of the patients in Group 2 and 60% (9 of 15) of the patients in Group 3. The presence of the bone scan abnormality was significantly lower in the two groups receiving iloprost. Most patients had follow-up information on whether they subsequently underwent at least one finger or toe amputation. The need for amputation was consistent with the bone scan findings.
According to the release, the most common side effects of the treatment include headache, flushing, heart palpitations, fast heart rate, nausea, vomiting, dizziness, and hypotension. The marketed product also has a warning and precautions noting that it may cause symptomatic hypotension.