2-Pyridinealdoxime methochloride
[CAS# 51-15-0]

Identification

• Classification: API >> Special medicine >> Antidote
• Name: 2-Pyridinealdoxime methochloride
• Synonyms: 2-PAM chloride; Pralidoxime chloride
• Molecular Formula: C₇H₉ClN₂O
• Molecular Weight: 172.61
• CAS Registry Number: 51-15-0
• EC Number: 200-080-9
• SMILES: C[N+]1=CC=CC=C1/C=N/O.[Cl-]

Properties

• Solubility: 10 mM (DMSO) (Expl.)
• Melting Point: 223 ºC (decomp.)(Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H312-H315-H319-H332
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P317-P321-P330-P332+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

2-Pyridinealdoxime methochloride is a chemical compound that is primarily used as an antidote in the treatment of poisoning caused by organophosphate and carbamate pesticides. It belongs to the class of oximes, which are compounds that can reverse the toxic effects of organophosphates by reactivating acetylcholinesterase, an enzyme that is inhibited by these poisons.

The discovery and development of 2-pyridinealdoxime methochloride stem from the need for effective antidotes against nerve agents and certain pesticides that inhibit acetylcholinesterase. Acetylcholinesterase is an essential enzyme in the nervous system that breaks down the neurotransmitter acetylcholine. When organophosphates and carbamates inhibit this enzyme, it leads to the accumulation of acetylcholine, resulting in overstimulation of muscles, glands, and the central nervous system. This can lead to severe symptoms, including muscle twitching, paralysis, respiratory failure, and even death.

2-Pyridinealdoxime methochloride works by binding to the phosphorus atom in the organophosphate molecule, displacing it from the acetylcholinesterase enzyme. This process reactivates the enzyme, allowing it to resume its normal function of breaking down acetylcholine. This helps to alleviate the toxic effects of the poison and restore normal neurological function.

In addition to its use in treating poisoning from pesticides and nerve agents, 2-pyridinealdoxime methochloride has been studied in relation to its potential therapeutic applications in other areas, such as in the treatment of diseases associated with acetylcholinesterase dysfunction. However, its primary clinical application remains as an antidote for organophosphate poisoning.

The compound is typically administered intravenously or intramuscularly in a clinical setting. It is often used in combination with atropine, another medication that helps to block the effects of excessive acetylcholine by inhibiting its receptors. This combination therapy helps to treat the symptoms of poisoning more effectively.

While 2-pyridinealdoxime methochloride is a valuable antidote, it is not without limitations. It is most effective when administered soon after exposure to organophosphate or carbamate poisoning, as the enzyme-inhibitor bond becomes increasingly difficult to break over time. The efficacy of 2-pyridinealdoxime methochloride may also vary depending on the specific type of organophosphate involved.

In conclusion, 2-pyridinealdoxime methochloride is a compound primarily used as an antidote for organophosphate and carbamate poisoning. It works by reactivating acetylcholinesterase, which is inhibited by these toxins, and is an important treatment option in cases of pesticide or nerve agent exposure. It is typically administered in combination with other treatments, such as atropine, to enhance its effectiveness.

References

2024. A Pralidoxime Nanocomplex Formulation Targeting Transferrin Receptors for Reactivation of Brain Acetylcholinesterase After Exposure of Mice to an Anticholinesterase Organophosphate. International Journal of Nanomedicine, 19.
DOI: 10.2147/ijn.s443498

1957. Pyridine-2-Aldoxime Methiodide and Poisoning by Anticholinesterases. Science (New York, N.Y.), 125(3251).
DOI: 10.1126/science.125.3251.743

1957. PYRIDINE-2-ALDOXIME METHIODIDE IN THE TREATMENT OF SARIN AND TABUN POISONING, WITH NOTES ON ITS PHARMACOLOGY. The Journal of Pharmacology and Experimental Therapeutics, 120(3).
DOI: 10.1016/s0022-3565(25)23276-1