Chinese alias: aeroporin;Arodotoxin B;Arup is sticky;Polymyxin B
English name: polymyxin B
English alias: Aerosporin;Polimixina B; Polimixina B [INN-Spanish]; Polymixin B; Polymyxine B; Polymyxine B [INN-French]; Polymyxinum B; Polymyxinum B [INN-Latin]; UNII-J2VZ07J96K
Polymyxin B Sulfate (Aerosporin) is a group of polypeptide antibiotics produced by Bacillus polymyxa.Polymyxin b and e are used for medicine.The commonly used sulfate is a white crystalline powder, which is easily soluble in water and has hygroscopicity.It is stable in acid solution, neutral solution at room temperature for one week does not affect the potency, and alkaline solution is unstable.
3. Isotonic specific volume (90.2K): none available
4. Surface tension (dyne/cm): none available
5. Dielectric constant: None available
6. Polarization rate (10-24cm3): none available
7. Single isotope mass: 1300.717306 Da
8. Nominal mass: 1300 Da
9. Average mass: 1301.5552 Da
Calculate chemical data
1. Number of hydrogen bond donors: 20
2. Number of hydrogen bond receptors: 22
3. Number of rotatable chemical bonds: 25
4. Number of tautomers: 1001
5. Topological molecule polar surface area (TPSA): 565
6. Number of heavy atoms: 82
7. Surface charge: 0
8. Complexity: 2010
9. Number of isotope atoms: 0
10. Determine the number of atomic structure centers: 0
11. Number of uncertain atomic structure centers: 10
12. Determine the number of chemical bond structure centers: 0
13. Number of uncertain chemical bond structure centers: 0
14. Number of covalent bond units: 2[3]
Properties and stability
If it is used and stored according to the specifications, it will not decompose, and there is no known dangerous reactionoxide
Storage method
Sealed, stored at 2 º C - 8 º C
Drug package insert of polymyxin sulfate B
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Product specification: 500000 units
Efficacy and indications: serious infection caused by aminoglycoside resistant, third-generation cephalosporin resistant bacteria, Pseudomonas aeruginosa or other sensitive bacteria, such as bacteremia, endocarditis, pneumonia, post burn infection, etc.
Chemical composition:<Its antibacterial spectrum and clinical application are similar to polymyxin E, and for gram-negative bacilli, [1]... [Details] Its antibacterial spectrum and clinical application are similar to polymyxin E.
Clinical effect
hisAntibacterial spectrumAnd clinical application is similar to polymyxin E, which has inhibitory or bactericidal effect on gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, paracoliform, Klebsiella pneumoniae, acidophilus, Bordetella pertussis and dysentery bacillus.Clinically, it is mainly used for infection caused by sensitive bacteria and urinary system infection caused by Pseudomonas aeruginosa, as well as eye, trachea, meningitis, sepsis, burn infection, skin and mucous membrane infection, etc.
pharmacological action
It has antibacterial effect on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Haemophilus, Enterobacteriaceae, Salmonella, Shigella, Pertussis, Pasteurella, Vibrio and other gram-negative bacteria.Proteus, Neisseria, Serratia, Prudential bacteria, Gram positive bacteria and obligate anaerobes are not sensitive to this kind of drugs.Bacteria have cross resistance to this product and polymyxin E, but there is no cross resistance between this drug and other antibiotics.
Not absorbed after oral administration.After injection, it is mainly excreted by urine, but only a small amount is excreted within 12 hours, and the concentration can reach 20-100 μ g/ml.Drug excretion continued within 1-3 days after drug withdrawal.
It is mainly used for infection of wounds, urinary tract, eyes, ears, trachea and other parts caused by Pseudomonas aeruginosa and other pseudomonas bacteria, as well as septicemia and peritonitis.
Usage and dosage
Oral, 100mg~200mg/time for adults, 3-4 times/day;Children are given 10mg~20mg/kg daily, four times.Intramuscular or intravenous injection, 50mg~100mg/day for adults, divided into 2~3 times;Children are 1.5 mg~2.5 mg/kg daily, divided into 3~4 times.
(1) For adults and children with normal renal function, intravenous drip of 1.5~2.5 mg/kg (generally not more than 2.5 mg/kg) per day shall be divided into two times, once every 12 hours.Every 50mg of this product is diluted with 500ml of 5% glucose solution and then dropped.Infants with normal renal function can tolerate the dosage of 4mg/kg per day.
(2) The intramuscular injection of 2.5~3mg/kg for adults and children is given in batches every 4~6 hours.The daily dose can reach 4mg/kg for infants and 4.5mg/kg for newborns.
(3) Inject intrathecally (for pseudomonas aeruginosa meningitis) to prepare 5mg/ml solution with sodium chloride injection.For adults and children over 2 years old, 5mg per day shall be used every other day for at least 2 weeks after 3 to 4 days of application until the cerebrospinal fluid culture is negative and the sugar content is normal.For children under 2 years old, use 2mg once a day for 3 to 4 consecutive days (or 2.5mg once every other day), and then use 2.5mg once every other day until normal.
(4) The concentration of eye drops is 1-2.5mg/ml.
Notes:
(1) The damage to the kidney is more common, and the dose should be reduced in patients with renal insufficiency.
(2) Intravenous injection may cause respiratory depression, which is generally not used.
(3) The intrathecal injection amount should not exceed 5mg once to prevent the stimulation of meninges or nerve tissue.
(4) It should not be used together with other drugs with nephrotoxicity or neuromuscular blocking effect to avoid accidents
side effect
1 The adverse reaction of oral or local administration is small, and there is no irritation due to unabsorbability.Large doses can cause gastrointestinal reactions such as nausea, vomiting and diarrhea.
High dose can cause kidney damage and nervous system dysfunction, such as numbness and edema around the mouth, and even respiratory depression in severe cases.
[Drug description]: each bottle of polymyxin sulfate B for injection is 50mg (1mg=10000 units).
matters needing attention
(1) The damage to the kidney is more common, and the dose should be reduced in patients with renal insufficiency.
(2) Intravenous injection may cause respiratory depression, which is generally not used.
(3) The intrathecal injection amount should not exceed 5mg once to prevent the stimulation of meninges or nerve tissue.
(4) It should not be used together with other drugs with nephrotoxicity or neuromuscular blocking effect to avoid accidents.
Treatment cases
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Meningitis cause
Bacterial meningitis is caused by some kind of bacterial infection.There are three types, namely Haemophilus influenzae type B, Neisseria meningitidis (diplococcus) and Streptococcus pneumoniae (pneumococcus).About 80% of the cases in the United States are bacterial meningitis.Usually a small number of healthy people carry these germs in the nose or on the body surface, which does not harm the human body. They are spread by coughing or sneezing.Some studies point out that people are most likely to be infected by germs when they have a cold, because inflammation of the nose makes it very easy for bacteria to enter the brain.Tuberculous meningitis is a non suppurative inflammation of the meninges caused by tubercle bacillus, accounting for about 6% of systemic tuberculosis.After the infection of Mycobacterium tuberculosis is spread by blood, it is planted under the pia mater to form a tuberculous nodule. After the nodule collapses, a large number of tuberculous bacteria enter the subarachnoid space.In recent years, the morbidity and mortality of tuberculous meningitis have increased.Early diagnosis and treatment can improve curative effect and reduce mortality.
Treatment of bacterial meningitis
(1) For the treatment of group B streptococcal meningitis, it is recommended to use penicillin G 500000 u/kg per day or aminocarbycline 300-400 mg/kg per day, plus gentamicin 0.75 mg/kg per day.It is difficult to treat meningitis caused by gram-negative bacilli, and the mortality rate of typical drug use of aminocarbycline plus an aminoglycoside is 20% - 30%.The third generation cephalosporins (such as cefotaxime) are the first choice for the treatment of confirmed gram-negative bacterial meningitis (or septicemia) or those confirmed septicemia.The special clinical conditions of meningitis also affect the choice of antibiotics. For example, newborns who are suspected of having sepsis within one week of birth and are given ampicillin and gentamicin treatment, and those who have sepsis and meningitis several weeks after birth should be combined with vancomycin and aminoglycosides of different types (such as amikacin)Or third-generation cephalosporins (such as cefotaxime), polymyxin B and other drugs.
(2) The age of the sick children has certain guiding significance for the students who are not selected. For example, the elderly children are less likely to suffer from influenza meningitis, and the newborns are mostly treated with drugs for intestinal gram-negative bacteria.It is generally advocated to use ordinary aminoglycoside penicillin, because gentamicin and amikacin are effective against intestinal gram-negative bacilli, while penicillin is effective against streptococcus, streptococcus pneumoniae, and meningococcus.Ampicillin, a broad-spectrum antibiotic, can also be used to replace penicillin, and the drug resistant strains can be benzylpenicillin plus cefotaxime.Neonates, especially immature children, generally avoid chloramphenicol. Because their liver and kidney are not yet mature, and their metabolism and excretion of chloramphenicol are not yet complete, they are prone to poisoning, manifested as "gray baby syndrome", or even death from shock.
(3) To ensure the effective concentration of drugs in cerebrospinal fluid: first, drugs that can easily penetrate the blood brain barrier should be selected to make the concentration of antibiotics in cerebrospinal fluid more than 10 times the inhibitory concentration.Pay attention to the method and dosage of administration.Chloramphenicol, sulfadiazine and trimethoprim (TMP) can reach the cerebrospinal fluid and maintain effective antibacterial concentration, especially chloramphenicol passes through the inflamed meninges.Meningeal permeability gradually returns to normal with the improvement of the condition, so the dose of drugs that continue to enter the cerebrospinal fluid also decreases.In order to ensure the therapeutic effect, large doses of drugs should be administered intravenously until the end of the course of treatment. The dosage should not be reduced midway or the method of administration should not be changed.
Erythromycin, carbenicillin, vancomycin, 1st to 2nd generation cephalosporins, and aminoglycosides antibiotics have poor ability to pass through the blood brain barrier. At this time, polymyxin B has a better effect.
(4) If the selected drug can pass through the blood-brain barrier well, in principle, intrathecal injection is not required to avoid adverse reactions and increase the pain of the patient. Gentamicin, amikacin and other drugs are not easy to reach the cerebrospinal fluid, so intrathecal or intraventricular injection can be used.If the diagnosis and treatment of late infantile encephalomyelia is delayed, there is pus formation on the appearance of cerebrospinal fluid, or bacteria are resistant to antibiotics, intrathecal injection of antibiotics can improve the cure rate.According to the retention time of antibiotics in the cerebrospinal fluid, the antibiotics are injected once a day or every other day, generally 3 to 5 times continuously, until the cerebrospinal fluid becomes clear, the number of cells decreases significantly, and bacteria disappear.When glucococcus or rare bacteria exist, or the cerebrospinal fluid still shows obvious inflammatory changes after 3~5 times of intrathecal injection, the intrathecal injection time can be prolonged, or even 7~10 times can be given continuously.During intrathecal injection, the drug must be diluted to a certain concentration. It can be diluted with drawn cerebrospinal fluid or normal saline. Note that the amount of injected fluid should be slightly less than the amount of discharged cerebrospinal fluid.The injection speed should be slow.
For bacterial meningitis, the use of aminoglycosides or polymyxin B in drug treatment is ideal.
