7703. Pralidoxime Chloride

Nomenclature

CAS number: 51-15-0
2-[(Hydroxyimino)methyl]-1-methylpyridinium chloride; 2-formyl-1-methylpyridinium chloride oxime; 1-methyl-2-formylpyridinium chloride oxime; N-methylpyridinium-2-aldoxime chloride; 2-pyridine aldoxime methyl chloride; 2-PAM chloride; Protopam (Wyeth).
C7H9ClN2O; mol wt 172.61.
C 48.71%, H 5.26%, Cl 20.54%, N 16.23%, O 9.27%.

Description and references

Cholinesterase reactivator. Prepn of salts: I. B. Wilson et al., US 2816113 (1957 to U.S. Sec'y. of Army); A. A. Kondritzer et al., J. Pharm. Sci. 50, 109 (1961). Manufacturing processes: R. I. Ellin et al., US 3140289 (1964 to U.S. Dept. of the Army); McDowell, US 3155674 (1964 to Olin Mathieson). Commercial prepn: R. I. Ellin, Ind. Eng. Chem. Prod. Res. Dev. 3 (1), 20 (1964). HPLC determn in serum: P. Houzé et al., J. Chromatogr. B 814, 149 (2005). Pharmacokinetics: D. Jovanovic, Arch. Toxicol. 63, 416 (1989). Toxicology: Christensen, Richter, Arch. Environ. Health 15, 599 (1967). Toxicity data: Fleisher et al., Toxicol. Appl. Pharmacol. 16, 40 (1970); R. I. Ellin, J. H. Wills, J. Pharm. Sci. 53, 1143 (1964). Comprehensive description: U. V. Banakar, U. N. Patel, Anal. Profiles Drug Subs. 17, 533-569 (1988). Clinical trial in organophosphorus pesticide poisoning: K. S. Pawar et al., Lancet 368, 2136 (2006).

Chemical structure

Properties

Crystals from alcohol + ether, mp 235-238° (dec). Soly (g/100 ml) 25°: acetone 0, isopropanol 0.09, ethanol 0.89, methanol 8.5, water 65.5. LD50 in rats (mg/kg): 96 i.v. (Fleisher). LD50 in rabbits (mg/kg): 95 i.v.; LD50 in mice (mg/kg): 115 i.v., 205 i.p., 4100 orally (Ellin, Wills).

Derivative

Pralidoxime iodide.

Nomenclature

CAS number: 94-63-3
2-Pyridine aldoxime methiodide; 2-PAM.
C7H9IN2O; mol wt 264.06.
C 31.84%, H 3.44%, I 48.06%, N 10.61%, O 6.06%.

Properties

Yellow crystals from alcohol, mp 225-226°. Soly at 25°: 48 mg/ml. Very sol in water, fairly sol in hot alcohol, poorly sol in cold alcohol. Insol in ether, acetone. LD50 in mice (mg/kg): 140-178 i.v., 136-260 i.p., 290-340 s.c., 1500-4000 orally (Ellin, Wills).

Derivative

Pralidoxime mesylate.

Nomenclature

CAS number: 154-97-2
Contrathion (Sanofi-Aventis).
C8H12N2O4S; mol wt 232.26.
C 41.37%, H 5.21%, N 12.06%, O 27.55%, S 13.81%.

Properties

Very hygroscopic crystals from ethanol, mp 155°. pKa 8.0. Soly in water: 1 g in 2 ml. LD50 in mice (mg/kg): 118-122 i.v., 216 i.p., 3700 orally; in rats (mg/kg): 109 i.v., 262 i.p. (Ellis, Wills).

Therapeutic Category

Antidote (nerve gases and organophosphate insecticide poisoning).

Therapeutic Category (Veterinary)

Antidote (organophosphate poisoning).

Keywords

Cholinesterase Reactivator; Antidote (Organophosphate Poisoning)