バンコマイシン 化学特性,用途語,生産方法
解説
バンコマイシン，Streptomyces orientalisの産生するグリコペプチド系抗生物質．バンコマイシン塩酸塩は白色の粉末．分解点120 ℃．UV(水)λmax 282 nm(ε 5800)．水に易溶，エタノールに難溶．グラム陽性菌，とくに多剤耐性黄色ぶどう球菌(MRSA)に有効な薬剤として有用である．ペプチドグリカン生合成段階で，D-Ala-D-Ala基に結合して細胞壁の合成を阻害するが，現在は，バンコマイシン耐性の腸球菌が出現している．塩酸塩が静注で使用される．
森北出版「化学辞典（第2版）
効能
抗生物質, 細胞壁合成阻害薬
毒性
LD50 489 mg/kg(マウス，静注)．
説明
Vancomycin is produced by fermentation of Amycol atopsis orientalis (formerly Nocardi a orientalis). It has
been available for approximately 40 years, but its popularity has increased significantly with the emergence
of MRSA in the early 1980s. Chemically, vancomycin has a glycosy lated hexapeptide chain that is rich in
unusual amino acids, many of which contain aromatic rings cross-linked by aryl ether bonds into a rigid
molecular framework.
使用
Vancomycin is used for serious bacterial infections caused by microorganisms sensitive
to this drug when penicillins and cephalosporins are ineffective for diseases such as sepsis,
endocarditis, pneumonia, pulmonary abscess, osteomyelitis, meningitis, and enterocolitis,
or when penicillins and cephalosporins cannot be tolerated by patients. Vancomycin is the
drug of choice for infections caused by methicillin-resistant forms of S. aureus, S. epidermidus, and other coagulase-negative staphylococci, as well as for endocarditis, diphtherioid
infections, and for patients very sick with colitis caused by C. difficile. A synonym of this
drug is vancocin.
定義
ChEBI: A complex glycopeptide from Streptomyces orientalis. It inhibits a specific step in the synthesis of the peptidoglycan layer in the Gram-positive bacteria Staphylococcus aureus and Clostridium difficile.
獲得抵抗性
Only very recently, despite decades of intensive use, have some vancomycin-resistant bacteria emerged
(vancomycin-resistant enterococcus [VRE] and vancomycin-resistant Staphylococcus aureus) [VRSA]. It is
alleged that these resistant strains emerged as a consequence of the agricultural use of avoparcin, a
structurally related antibiotic that has not found use for human infections in the United States but was used
in Europe before its recent ban. The mechanism of resistance appears to be alteration of the target
D-alanyl-D-alanine units on the peptidoglycan cell wall precursors to D-alanyl-D-lactate. This results in
lowered affinity for vancomycin due to lack of a key hydrogen bonding interaction. It is greatly feared that
this form of resistance will become common in the bacteria for which vancomycin is presently the last sure
hope for successful chemotherapy. If so, such infection
would become untreatable. These resistant strains are not yet common in clinically relevant strains, but most
authorities believe that this is only a question of time. Vancomycin-intermediate S.aureus, also called
glycoprotein-intermediate S.aureus (VISA), also has been reported. It appears to be resistant because of a
thickened peptidoglycan layer.
作用機序
Vancomycin is a bacterial cell wall biosynthesis inhibitor. Evidence suggests that the active species is a
homodimer of two vancomycin units. The binding site for its target is a peptide-lined cleft having high affinity
for acetyl-D-alanyl-D-alanine and related peptides through five hydrogen bonds. It inhibits both
transglycosylases (inhibiting the linking between muramic acid and acetyl glucosamine units) and
transpeptidase (inhibiting peptide cross-linking) activities in cell wall biosynthesis. Thus,
vancomycin functions like a peptide receptor and interrupts bacterial cell wall biosynthesis at the same step
as the β-lactams do, but by a different mechanism. By covering the substrate for cell wall transamidase, it
prevents cross-linking resulting in osmotically defective cell walls.
臨床応用
Although a number of adverse effects can result from IV infusion, vancomycin has negligible oral
activity. It can be used orally for action in the GI tract, especially in cases of Cl ostri di um difficile overgrowth. The useful spectrum is restricted to Gram-positive pathogens, with particular utility against
multiply-resistant, coagulase-negative staphylococci and MRSA, which causes septicemias, endocarditis,
skin and soft-tissue infections, and infections associated with venous catheters.
副作用
Vancomycin is highly associated with adverse infusion-related events. These are especially prevalent with
higher doses and a rapid infusion rate. A rapid infusion rate has been shown to cause anaphylactoid
reactions, including hypotension, wheezing, dyspnea, urticaria, and pruritus. A significant drug rash (the
so-called red man syndrome) also can occur. These events are much less frequent with a slower infusion
rate.
In addition to the danger of infusion-related events, higher doses of vancomycin can cause nephrotoxicity
and auditory nerve damage. The risk of these effects is increased with elevated, prolonged concentrations,
so vancomycin use should be monitored, especially in patients with decreased renal function. The ototoxicity
may be transient or permanent and more commonly occurs in patients receiving high doses, patients with
underlying hearing loss, and patients being treated concomitantly with other ototoxic agents (i.e.,
aminoglycosides).
バンコマイシン 上流と下流の製品情報
原材料
準備製品