Dimercaprol, also called British anti-Lewisite (BAL), is a

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

used to treat acute poisoning by

arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

, mercury,

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

, and

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

. It may also be used for

antimony Antimony is a chemical element; it has chemical symbol, symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (). Antimony compounds have been known since ancient t ...

thallium Thallium is a chemical element; it has Symbol (chemistry), symbol Tl and atomic number 81. It is a silvery-white post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Che ...

, or bismuth poisoning, although the evidence for those uses is not very strong. It is given by injection into a muscle. Common side effects include

high blood pressure Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...

, pain at the site of the injection, vomiting, and

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

. It is not recommended for people with peanut allergies as it is typically formulated as a suspension in peanut oil. It is unclear if use in

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

is safe for the baby. Dimercaprol is a chelator and works by binding with heavy metals. It has a very pungent odor. Dimercaprol was first made during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. It is on the World Health Organization's List of Essential Medicines.

Medical uses

Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, and it is an essential drug. It is also used as an antidote to the chemical weapon

Lewisite Lewisite (L) (A-243) is an organoarsenic compound. It was once manufactured in the United States, Japan, Germany and the Soviet Union for use as a Chemical warfare, chemical weapon, acting as a vesicant (blister agent) and lung irritant. Although ...

. Nonetheless, because it can have serious

adverse effect An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term compli ...

s, researchers have also pursued development of less toxic analogues, such as succimer. Wilson's disease is a

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders ...

in which

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

builds up inside the

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

and other tissues. Dimercaprol is a copper chelating agent that has been approved by the FDA to treat Wilson's disease. Dimercaprol also shows effectiveness against snakebite by potently antagonizing the activity of Zn²⁺-dependent

snake venom Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is usually injected by unique fangs during a Snakebite, bite, though ...

metalloproteinases ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

''.

Mechanism of action

Arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

and some other heavy metals act by chelating with adjacent thiol residues on metabolic enzymes, creating a chelate complex that inhibits the affected enzyme's activity. Dimercaprol competes with the thiol groups for binding the metal ion, which is then excreted in the urine. Dimercaprol is itself toxic, with a narrow therapeutic range and a tendency to concentrate arsenic in some organs. Other drawbacks include the need to administer it by painful

intramuscular injection Intramuscular injection, often abbreviated IM, is the medical injection, injection of a substance into a muscle. In medicine, it is one of several methods for parenteral, parenteral administration of medications. Intramuscular injection may be ...

Serious side effects include nephrotoxicity and

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

. Dimercaprol has been found to form stable chelates ''in vivo'' with many other metals including inorganic mercury,

, bismuth, cadmium, chromium,

cobalt Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. ...

, and nickel. However, it is not necessarily the treatment of choice for toxicity to these metals. Dimercaprol has been used as an adjunct in the treatment of the acute encephalopathy of lead toxicity. It is a potentially toxic drug, and its use may be accompanied by multiple side effects. Although treatment with dimercaprol will increase the excretion of cadmium, there is a concomitant increase in renal cadmium concentration, so that its use in case of cadmium toxicity is to be avoided. It does, however, remove inorganic mercury from the kidneys; but is not useful in the treatment of alkylmercury or phenylmercury toxicity. Dimercaprol also enhances the toxicity of

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

and tellurium, so it is not to be used to remove these elements from the body.

History

The original name of dimercaprol reflects its origins as a compound secretly developed by British biochemists at Oxford University in the beginning of the

, with the first synthesis in July 1940 as an antidote for

lewisite Lewisite (L) (A-243) is an organoarsenic compound. It was once manufactured in the United States, Japan, Germany and the Soviet Union for use as a Chemical warfare, chemical weapon, acting as a vesicant (blister agent) and lung irritant. Although ...

, a now-obsolete

-based chemical warfare agent.

References

External links

* {{Authority control Primary alcohols Antidotes Chelating agents Thiols World Health Organization essential medicines Wikipedia medicine articles ready to translate

Medical uses

Mechanism of action

History

See also

References

External links