Melarsoprol

A medication used to treat African trypanosomiasis

Melarsoprol 2D Structure

Melarsoprol is a medication used for the treatment of African trypanosomiasis, also known as sleeping sickness. It is specifically used for the late stage of the disease, where the infection has reached the central nervous system. Melarsoprol is an organoarsenic compound and is known for its high toxicity, which limits its use.

Medical uses

Melarsoprol is primarily used to treat the second stage of Trypanosoma brucei infections, which are caused by the protozoan parasites Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. These parasites are transmitted to humans through the bite of an infected tsetse fly. The second stage of the disease is characterized by the involvement of the central nervous system, leading to neurological symptoms such as confusion, poor coordination, and disturbances in sleep patterns.

Mechanism of action

Melarsoprol works by inhibiting the enzyme trypanothione reductase, which is essential for the survival of the trypanosome parasites. This enzyme is involved in the redox metabolism of the parasites, and its inhibition leads to the accumulation of toxic substances within the parasite, ultimately causing its death.

Side effects

The use of melarsoprol is associated with significant side effects due to its arsenic content. Common adverse effects include fever, vomiting, abdominal pain, and encephalopathy. The latter, known as reactive encephalopathy, can be fatal and occurs in approximately 5-10% of patients. Due to these severe side effects, melarsoprol is often considered a treatment of last resort.

History

Melarsoprol was developed in the 1940s and has been used extensively in the treatment of sleeping sickness. Despite its toxicity, it remains an important drug in regions where the disease is endemic, particularly in sub-Saharan Africa, due to the lack of alternative treatments for the late stage of the disease.

Alternatives

In recent years, alternative treatments such as eflornithine and nifurtimox have been developed and are used in combination therapies to reduce the reliance on melarsoprol. These alternatives are generally less toxic and have been shown to be effective in treating the second stage of sleeping sickness.

Melarsoprol 3D Spacefill Model

Related pages

• African trypanosomiasis
• Trypanosoma brucei
• Tsetse fly
• Eflornithine
• Nifurtimox