Known as Anascorp, it was found to cause few allergic reactions and was approved after a series of clinical trials by the University of Arizona.
"This product provides a new treatment for children and adults and is designed specifically for scorpion stings," Karen Midthun, M.D., director of the FDA's Center for Biologics Evaluation and Research, said in a statement.
"Scorpion stings can be life-threatening, especially in infants and children," she said.
The drug was approved because there was no specific treatment in the United States for these types of stings, which can cause loss of muscle control and shortness of breath and, in the worst-case scenario, require hospitalization, Midthun said.
Developed using the plasma of horses immunized with scorpion venom and vaccinated against human viruses, Anascorp may cause early or delayed allergic reactions in people sensitive to horse proteins, the FDA said.
"This is a historic event," said Dr. Leslie Boyer, director of UA's VIPER Institute, who oversaw the clinical trials.
"This is the first-ever drug approved for this use by the FDA; the first-ever drug that we are aware of being developed fully in Latin America and subsequently approved by the FDA," the scientist said.
Around 11,000 people are stung each year in the southwestern U.S. state of Arizona by scorpions, while there were 17,000 cases nationwide in 2009. Anascorp is a treatment for stings by the most common type of scorpion found in the U.S. - the Centruroides, or bark, scorpion.
The effectiveness of Anascorp, manufactured by the Mexican firm Instituto Bioclon, S.A. de C.V., was determined through a study involving 15 children with neurological symptoms stemming from scorpion stings.
The symptoms resolved in just four hours in all eight children who received Anascorp, but only in one of the children who were administered a placebo, the FDA said.
The most common side-effects of Anascorp were found to be vomiting, fever, rash, nausea, itchiness, runny nose, headache and muscle pain.