Melarsoprol (MLS)

Melarsoprol is a medicinal drug used in human African trypanosomiasis. Melarsoprol is also used in the treatment of trypanosomiasis, such as Chagas disease and West African sleeping sickness, the former caused by Trypanosoma cruzi and the latter by Trypanosoma brucei gambiense. Being a toxic organic compound of arsenic, melarsoprol is a highly dangerous treatment which is only administered by injection under the supervision of a physician, as it can produce similar effects as arsenic poisoning. Among clinicians, it is colloquially referred to as "Arsenic in antifreeze". It is known to cause a range of side effects including convulsions, fever, loss of consciousness, rashes, bloody stools, nausea, and vomiting. Eflornithine is a more modern and far less dangerous treatment for sleeping sickness, but it is expensive, it is not widely available on the market, and most of its supply comes from donations from its manufacturer.