Snakebites are uncommon in the United States, but when they occur can be devastating and even lead to the death of the victim. The World Health Organization estimates that about 100,000 people throughout the world die each year due to snakebites. Treatment usually involves applying a pressure bandage to prevent the spread of the snake venom which usually moves by lymphatic drainage to the bloodstream. In addition, the use of antivenom is needed in order to provide antibodies that neutralized the toxic effects of the snake venom. In many parts of the world that have cobras, mambas, and other neurotoxin producing snakes, there may be a new treatment modality that will help in the fight to prevent the spread of the venom. Researchers from the University of Newcastle in Australia, lead by Dr. Dirk van Helden, have described a method that slows the spread of the neurotoxin containing venom through the lymphatic system. Their method involves applying nitroglycerin ointment upon the limb that has been snake bitten. Their research was published online in the journal Nature Medicine. Most commonly, nitroglycerin is used in patients with coronary artery disease to alleviate the chest pain caused by angina. In the case of a patient that has been bitten by a snake, the researchers found that nitroglycerin can also slow down the spread of the venom. In their studies, the researchers injected volunteers in the leg with a tracer compound and found that application of nitroglycerin ointment slowed the spread of the tracer compound to the groin. When the nitroglycerin ointment was applied, the transit time of the tracer compound was 54 minutes as compared to 13 minutes without the ointment. To test whether this method would increase survival, the researchers injected the feet of rats with snake venom and showed that application of the nitroglycerin ointment allowed the rats to live 50% longer. This newly discovered role for the use of nitroglycerin ointment may give snake bite victims more time to reach medical care. Time is a critical factor in the survival of snake bite victims because survival depends upon rapid administration of antivenom. Providing more time to reach medical care should impact the survival of these patients and hopefully lead to a decreased mortality from this illness.
Megan E. Saul et al. “A pharmacological approach to first aid treatment for snakebite” Nature Medicine published online 26 June 2011