Temocillin Chemische Eigenschaften,Einsatz,Produktion Methoden
Verwenden
Antibacterial.
Antimicrobial activity
The introduction of the 6-α-methoxy
group has resulted in loss of activity against Gram-positive
cocci and anaerobic Gram-negative bacilli, but it is active
against enterobacteria (MIC 1–8 mg/L), H. influenzae and
Mor. catarrhalis, with somewhat elevated MICs against
carbapenemase-
producing isolates of K. pneumoniae (MIC 16–64 mg/L) and Esch. coli (modal MICs 8–16 mg/L). In most
cases, β-lactamase-positive and negative strains are equally
susceptible. In contrast to the structurally related ticarcillin,
it is inactive against Ps. aeruginosa, but Burkholderia cepacia,
Ps. acidovorans and Aeromonas spp. are susceptible (MIC
4 mg/L). Most Acinetobacter spp. are resistant, and Ser. marcescens
exhibits variable susceptibility.
It is bactericidal at concentrations 2–4 times the MIC; filaments
formed at lower concentrations slowly lyse at higher drug
levels. Temocillin consists of diastereoisomers. The naturally
predominant R epimer is more rapidly bactericidal than the
S epimer. It is highly resistant to most bacterial β-lactamases,
including those that confer resistance to extended-spectrum
cephalosporins. It is hydrolyzed by β-lactamases produced by
Flavobacterium spp. and by those of Bacteroides spp.
Pharmakokinetik
Oral absorption: Negligible
C
max 1 g intramuscular injection: 70 mg/L
1 g rapid intravenous infusion:
172 mg/L after 5 min
Plasma half-life: 4.3–5.4 h
Plasma protein binding: 85%
Absorption and distribution
It is not absorbed when given orally and must be administered
parenterally. Relatively high protein binding, together
with its distribution in a volume less than the extracellular
fluid, accounts for its relatively low renal clearance and subsequent
high urinary concentrations that may be effective
against some Enterobacteriaceae resistant to other β-lactam
antibiotics. In artificial blister fluid and peritoneal fluid, concentrations
reach 50% of the peak plasma level; in lymph,
concentrations reach 25–60% of the simultaneous plasma
level, with a similar half-life. The R epimer differs from the S
epimer in lower protein binding, a 25% greater volume of distribution
and a 60% shorter half-life.
Metabolism and excretion
Elimination is principally in the glomerular filtrate, with 80% of
the dose appearing in the urine in the first 24 h. A small amount
is disposed of in the bile and by degradation. Elimination
declines in parallel with renal function, the half-life reaching 30 h
in patients with creatinine clearance below 5%.
Clinical Use
Severe infection with susceptible bacteria, including urinary and
respiratory tract infections, peritonitis and septicemia.
Nebenwirkungen
As with all penicillins, hypersensitivity reactions, including
serious anaphylactic responses, may occur. It is generally well
tolerated and administration of 4 g intravenously every 12 h
produced no significant effect on template bleeding time,
prothrombin
time or ADP-induced platelet aggregation.
Temocillin Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
