Name | 2-Pyridinealdoxime methochloride |
Synonyms | 2-PAM chloride Pralidoxime chloride 2-Pyridinealdoxime methochloride Pyridine-2-aldoxime methochloride Pyridine-2-carbaldoxime methochloride N-Methylpyridinium-2-carboxaldoxime chloride 2-hydroxyiminomethyl-1-methylpyridinium chloride 2-[(E)-(hydroxyimino)methyl]-1-methylpyridinium chloride (E)-(1-methylpyridin-2(1H)-ylidene)-N-oxomethanaminium chloride |
CAS | 51-15-0 |
EINECS | 200-080-9 |
InChI | InChI=1/C7H8N2O.ClH/c1-9-5-3-2-4-7(9)6-8-10;/h2-6H,1H3;1H |
Molecular Formula | C7H9ClN2O |
Molar Mass | 172.61 |
Density | 1.3265 (rough estimate) |
Melting Point | 215-225℃ |
Water Solubility | 65.5 g/100 mL (25℃) |
Storage Condition | -20℃ |
MDL | MFCD00011981 |
Physical and Chemical Properties | Chemical properties yellow white crystalline powder. Melting point 235-238 ℃ (decomposition). The solubility in water at 25°C is 640mg/ml. |
Use | Used as an antidote |
Hazard Symbols | Xn - Harmful |
Risk Codes | R20/22 - Harmful by inhalation and if swallowed. R36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S37/39 - Wear suitable gloves and eye/face protection |
Raw Materials | 2-Picoline Ethyl nitrite Dimethyl sulfate METHYL CHLORIDE Sodium hydroxide Nitrosyl chloride PYRIDINE-2-ALDOXIME |
Downstream Products | PYRIDINE-2-CARBOXALDOXIME METHIODIDE |
storage conditions | Inert atmosphere,Room Temperature |
acidity coefficient (pKa) | pKa 7.8-8 (Uncertain) |
water solubility | 65.5 g/100 mL (25 °C) |
Merck | 14,7703 |
BRN | 4163981 |
EPA chemical information | Pralidoxime chloride (51-15-0) |
WGK Germany | 3 |
RTECS number | UU4200000 |
customs code | 29333999 |
Toxicity | 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) |
overview
Phosphorus chloride (Pralidoxime Chloride), alias Pam chloride, phosphorus chloride, etc., this drug is an organophosphate antidote and other rescue drugs, is a cholinesterase resurrection agent, and is an injection type The drug is mainly used for the rescue of moderate and severe organophosphorus poisoning. Parathion, phosphorus absorption, phorate, methamidophos, tep, etc. have good curative effects. Its nucleophilic group can be directly combined with the phosphorylation group of cholinesterase and then jointly separated from cholinesterase, so that cholinesterase can be restored to its original state and reappear vitality, so as to relieve the symptoms of poisoning. For mild organophosphorus poisoning, the product can be used alone to control symptoms; for moderate and severe poisoning, atropine must be combined. After intravenous administration, the effective concentration in the blood is quickly reached. In large doses, it can enter the brain tissue through the blood-brain barrier, and it is quickly discharged from the kidney without accumulation of poisoning. It has been widely used at present, and there are many drug companies in China.
mechanism of action
this product is a hip compound. its quaternary ammonium group can tend to the cationic site of phosphorylated cholinesterase that has lost its vitality combined with organophosphorus insecticides. its nucleophilic group can directly combine with the phosphorylation group of cholinesterase and then jointly separate from cholinesterase, so that cholinesterase can return to its original state and reappear its vitality. the effect of being "aged" cholinester. This product has obvious effect on nicotine-like symptoms caused by organophosphorus insecticides, but has weak effect on toxinoid-like symptoms, and has no obvious effect on central nervous system symptoms.
applicable symptoms
It can replace iodide, and has different degrees of resurrection effect on the cholinesterase activity inhibited by acute organophosphorus insecticides, and rescues the poisoning of a variety of organophosphate insecticides, but it has no resurrection effect on the cholinesterase inhibited by carbamate insecticides. It has poor rescue effect on malathion, trichlorfon, dichlorvos, dimethoate, mef.
Pharmacokinetics
this drug is an injection drug. after intramuscular injection or intravenous injection of this drug, its concentration peak in the blood is maintained for 2~3 hours, and then gradually decreases. Intramuscular injection of this product is 7.5 mg/kg or 10 mg/kg, which can reach the effective therapeutic concentration of plasma 4 μg/ml. The half-life (t1/2) is 77min. The drug is rapidly metabolized in the tissues of the body, and it is quickly excreted in the urine through the kidney in its original shape and its metabolites.
usage and dosage
this product is intramuscular injection. for adults with mild poisoning, 0.5~0.75g is injected intramuscularly once, and repeated once after 1 hour if necessary. For moderate poisoning patients, intramuscular injection or slow intravenous injection after dilution is used, 0.75~1.5g for the first time, and 0.5~1.0g can be repeated every 1 hour thereafter. When muscle fibrillation disappears or blood cholinesterase activity returns to normal 60% or above, the drug can be reduced or stopped as appropriate. For severely poisoned patients, 1.5~2.5g is injected intramuscularly or diluted in two places for the first time and then injected intravenously slowly. After that, 1.0~1.5g is repeatedly administered every 0.5~1 hour, and the dosage is slowly reduced according to the situation.
for children: the usage of this product is the same as that of adults, but the dosage is reduced. Mild poisoning patients are 15~20mg/kg according to their body weight once; For moderate poisoning patients, 20~30mg/kg according to their body weight once; For severe poisoning: 30mg/kg according to their body weight once.
drug interactions
this product can enhance the biological effect of atropine, so the dose of atropine should be reduced when the two drugs are applied at the same time. In general, the first dose of atropine is 2~4mg every 10min, and the severe poisoning is 4~6mg, intramuscular or intravenous injection every 5~10min until atropinization occurs. Atropinization should be maintained for 48 hours, and then the dose of atropine should be gradually reduced or the interval between injections should be prolonged.
adverse reactions
can cause nausea, vomiting, increased heart rate, temporary S-T segment depression on electrocardiogram and prolonged Q-T time. Injection speed too fast can cause vertigo, blurred vision, diplopia, uncoordinated movement. An excessive dose can inhibit breathing and cause seizures. In severe cases, headache, dizziness, blurred vision, diplopia, and uncoordinated movements occurred.
Overview, mechanism of action, pharmacokinetics, adverse reactions, precautions, etc.
precautions
When this product is used in the elderly, the dosage should be appropriately reduced and the speed of intravenous injection should be slowed down. Organophosphorus insecticide poisoning patients with the application of this product as early as possible, the skin absorption caused by poisoning patients, the application of this product at the same time to take off the contaminated clothes, and wash hair and skin with soap. Oral poisoning patients were thoroughly lavaged with 2.5% sodium bicarbonate solution. Since organophosphorus insecticides can be absorbed in the lower digestive tract, oral patients should maintain this product for at least 48~72 hours to prevent delayed absorption from aggravating poisoning or even death. Coma patients to keep the respiratory tract unobstructed, respiratory depression should be immediately artificial respiration. During the medication process, blood cholinesterase should be measured at any time as a medication monitoring index, requiring blood cholinesterase to be maintained above 50% ~ 60%. The level of blood cholinesterase in patients with acute poisoning is related to clinical symptoms, and clinical manifestations must be closely observed. At the same time, when using this drug, the dosage should be strictly controlled. When the drug is overdose, it can also inhibit cholinesterase and aggravate poisoning.
production method
2-methylpyridine reacts with methyl chloride to obtain 2-methylpyridine chloromethane salt, nitrosates the base and ethyl nitrite to obtain phosphorolytic sodium chloride, and then neutralizes with concentrated hydrochloric acid in ethanol solution to pH = 3-4, filters out sodium chloride, concentrates the filtrate under reduced pressure to recover ethanol, obtains crude chlorolytic phosphonium, dissolves in distilled water, decolorizes with activated carbon, and recryst.