SSG
Meaning of SSG: Three letters for an antimony compound whose established job is a parasitic infection, not the cancer research the abbreviation is usually filed under.
Definition of SSG
SSG is the abbreviation for sodium stibogluconate, an antimony containing drug used to treat leishmaniasis, a parasitic infection spread by sandfly bites. It is given by injection over a course of weeks. Separately, it has been studied in cancer as a blocker of enzymes that switch off immune signaling, but that second use remains investigational.
What is it actually used for?
Leishmaniasis. The parasite is carried by sandflies and produces either skin ulcers that heal slowly and scar, or a far more serious internal form that enlarges the spleen and liver and is fatal untreated. Pentavalent antimony compounds have been the mainstay against both for decades across much of the world, and sodium stibogluconate is one of the two in common use. Resistance is now widespread in parts of South Asia, where newer drugs have displaced it, while it remains standard elsewhere.
How does it work?
The pentavalent antimony in the injected drug is thought to be converted inside the body to a trivalent form, and that form is the one that kills the parasite. It disrupts the parasite's energy production and the sulfur chemistry it relies on to survive inside a host cell. Host immune cells appear to do part of the work, which is why the drug performs poorly when immunity is impaired.
Why does an oncology dictionary list it?
Because of a second, unrelated property. The compound inhibits protein tyrosine phosphatases, enzymes that act as off switches for the signals interferon uses to rouse immune cells. Blocking those switches prolongs the signal, which raised the idea of pairing it with interferon against solid tumors and lymphoma. Early trials were run and nothing established came of them. Describing SSG only as a substance under study for cancer leaves out the disease it has actually treated for generations.
What limits its use?
Antimony is a heavy metal and the course is long. Aching muscles and joints, raised pancreatic enzymes with pancreatitis, liver enzyme rises, and changes in the heart's electrical recovery are all recognized during treatment, and the last of these is why the heart rhythm is watched. The injections themselves are painful. Cost, resistance and the need for repeated supervised dosing shape where the drug is still used.
Also known as
Used in a sentence
Sodium stibogluconate, written as SSG in the notes, was given for cutaneous leishmaniasis.
Good to know
Sources describing SSG only as a substance being studied in cancer omit its established role, since pentavalent antimony has been a mainstay of leishmaniasis treatment for decades despite growing resistance.