Generality
Chloroform - otherwise known as trichloromethane (CHCl3) - is a molecule used in the past as an inhalation general anesthetic; this use was later abandoned due to its toxicity.
History and uses
Between 1830 and 1831, chloroform was synthesized by several researchers, including the American physician Samule Guthrie, the German chemist J. F. von Liebig and the French scientist E. Soubeiran.
These scholars were able to obtain chloroform through a reaction between chlorinated lime (or calcium hypochlorite, Ca (ClO) 2) and ethanol, or, alternatively, acetone.
However, these researchers did not know the chemical structure of the compound and speculated that they had synthesized dichloroethane.
It was only in 1834 that the chemical formula of this substance was identified, thanks to the work done by the French chemist J. B. Dumas and it was he who gave this compound the name of chloroform.
A few years later, in 1842, the English doctor Robert Glover, through laboratory studies carried out on animals, discovered the anesthetic activity of chloroform.
Later, in 1847, chloroform was first used as an anesthetic drug by the Scottish dentist Francis Brodie Imlach.
Within a short period of time, the use of chloroform as an anesthetic drug during surgical procedures spread rapidly throughout Europe and the United States.
However, the therapeutic use of chloroform has led to the death of several patients, most likely due both to the administration of too high dosages and to the intrinsic toxicity (particularly in the heart) of chloroform.
During the last years of the 19th and the beginning of the 20th century, the use of chloroform as a general anesthetic was the subject of many debates, due to the fatal consequences that often occurred during the anesthesia induced with this drug.
Later, with the discovery of new types of anesthetics, safer and less toxic, the use of chloroform was gradually abandoned.
Mechanism of action
The anesthetic action exerted by chloroform is very powerful. Furthermore, this action is also associated with significant muscle relaxant and analgesic activities.
Once inhaled, the chloroform reaches the lungs, then to the alveoli, where it reaches the bloodstream.
Through the bloodstream, chloroform reaches the central nervous system, where it exerts its depressing activity, counteracting cellular excitability and favoring the onset of anesthesia.
The side effects affecting the heart that chloroform is able to induce are probably related to its ability to interact with potassium channels.
Side effects
As mentioned, the main side effects of chloroform occur at the cardiovascular level. In fact, this molecule is capable of causing severe cardiac arrhythmias and severe hypertension which can also lead to death, but not only.
Chloroform also has a marked hepatotoxicity and an "equally significant nephrotoxicity, which occur mainly following a" prolonged exposure to the compound.
In addition to this, chloroform can also cause side effects on the skin, which can manifest themselves in the form of skin irritations. In addition, it can cause the onset of severe allergic reactions associated with hyperpyrexia in sensitive individuals.
Carcinogenic activities are also attributed to chloroform; in particular, it seems to be responsible for the onset of hepatocellular carcinomas.
Furthermore, some studies conducted on animals have shown that exposure to this molecule can cause abortion and fetal malformations; in addition to causing alterations of the sperm.
Although there are no data on its effects on fertility and human reproduction, chloroform must not be handled and used by pregnant women and by mothers who are breastfeeding.
Current uses
Currently, chloroform is used as a solvent in research laboratories and, since it is a substance classified as toxic and irritating, it should only be handled by specialized personnel with adequate personal protective equipment (coat, gloves, etc.).
In any case, whenever possible, even within the research laboratories we try to avoid the use of chloroform in favor of less toxic solvents.
Deuterated chloroform (CDCl3) - ie the chloroform obtained by replacing the hydrogen atom with a deuterium atom - is, on the other hand, used as a solvent in a particular type of spectroscopic technique: NMR or nuclear magnetic resonance spectroscopy.
