Dwindling global supplies of anti-venom will leave tens of thousands of people at risk of dying from snakebites, medical charity Médecins Sans Frontières (Doctors Without Borders, MSF) has said.
MSF said that supplies of Fav-Afrique, the only anti-venom shown to be effective at treating a variety of snakebites across Africa, are due to go out of date in June 2016, with no indications so far that there will be an adequate replacement.
There are alternative drugs, but they are seen as less effective.
"We are now facing a real crisis so why do governments, pharmaceutical companies and global health bodies slither away when we need them most?" said Dr Gabriel Alcoba, a medical advisor on snakebites with MSF.
Fav-Afrique is produced by French pharmaceutical company Sanofi, which stopped manufacturing the drug in 2014 in the face of cheaper competition.
A spokesman for Sanofi told the Associated Press that the company had signaled it had become uneconomical for the company to produce the anti-venom as long ago as 2010.
"It's very strange that the relevant stakeholders are only realising this problem five years later," Alain Bernal was quoted as saying.
He said that the company had offered to transfer anti-venom technology to other companies but there had yet to be any uptake.
About five million people worldwide are bitten by snakes each year, according to MSF, out of whom 100,000 die and 400,000 are permanently disabled or disfigured.