Suramin is a drug commonly used in the treatment of African sleeping sickness and onchocerciasis, also known as river blindness. It is an odorless, tasteless, white powder which is dissolved in saline and administered intravenously. It is an effective remedy for a number of parasitic diseases, and has been widely used for this purpose since the early 1920s. More recently, suramin has shown some promise in the treatment of certain cancers.
The drug was first isolated in the early 1900s by the German chemist Paul Ehrlich, who found that certain napthaline-based dyes could partially treat African sleeping sickness in cattle. While the dyes themselves did not have a high rate of success, and had the unfortunate side effect of permanently discoloring the meat of treated cattle, the results were promising enough to merit further investigation. A synthetic form of the active compound in the dye was created by a team of Ehrlich's former colleagues in 1916, and became the primary treatment for African sleeping sickness and river blindness for most of the 20th century. Suramin is still a popular treatment for these diseases in much of the world due to its low cost compared with more recent synthetic remedies.
Suramin treats African sleeping sickness and river blindness by inhibiting growth factors within the parasites that cause the disease. By reducing the ability of worms and nematodes to produce insulin, platelets, and dermal cells, the drug interferes with the parasites' ability to replace old cells and produce energy. As their energy levels drop, the parasites face eventual immobility and death.
Experimental trials conducted since the late 1980s have shown a link between suramin treatment and the growth inhibition of a range of neoplastic tumors. Its potential value as an anticancer agent is based on its ability to slow the growth of inoperable tumors in metastatic cancers, increasing the possible effectiveness of other cancer treatments. Trials have not moved past the clinical stage, mostly due to uncertainty surrounding the exact mechanism by which suramin inhibits tumor growth and the discovery that the drug actually accelerates the growth of certain kinds of cancer.
Suramin treatment can lead to a number of potential side effects, most commonly nausea, vomiting, and an itchy rash. More seriously, it can also cause kidney damage in some individuals, and is generally not prescribed to those with existing renal problems. The drug is capable of causing temporary or permanent impairment of the adrenal cortex in rare cases. Overdose can lead to kidney damage and possible renal failure. Serious side effects are relatively rare, and the drug is considered safe in most cases.