dimercaptopropaanesulfonihappo

Dimercaptopropanol, commonly known as dimercaprol or BAL (British anti-Lewisite), is a chelating agent used in the treatment of certain heavy metal poisonings. It contains two thiol groups that bind metal ions to form stable chelate complexes, enhancing their solubility and elimination from the body. BAL is capable of crossing cell membranes, including the blood–brain barrier, which allows it to address neurotoxic metal exposures in some cases.

The primary clinical uses of BAL are in acute poisonings by arsenic and inorganic mercury, where it can rapidly reduce toxic metal levels. It has historically been used as an antidote to lewisite, an arsenical chemical warfare agent, which gave BAL its name. In modern practice, its role has become more limited due to toxicity concerns and the availability of safer alternatives such as dimercaptosuccinic acid (DMSA) and dimercaptopropane sulfonate (DMPS). BAL is sometimes used in combination with other chelators in severe cases or when other treatments are not suitable, under close medical supervision.

Administration is by intramuscular injection, typically in a hospital setting, with dosing and duration guided by the severity of poisoning and patient response. BAL can cause significant adverse effects, including hypertension, tachycardia, nausea, vomiting, diaphoresis, fever, and renal toxicity, as well as local injection-site reactions. Because of these risks and the development of less toxic agents, BAL is now used selectively rather than as a first-line antidote in most heavy metal poisonings.