Cefotaxime

Absorption

Rapidly absorbed following intramuscular injection.

Toxicity

Adverse effects following overdosage include nausea, vomiting, epigastric distress, diarrhea, and convulsions. Oral rat LD50 is over 20,000 mg/kg while intravenous rat LD50 is over 7,000 mg/kg.

Description

Like other third-generation cephalosporins, it has excellent anti-Gram-negative activity and is useful institutionally. It has a metabolically vulnerable acetoxy group attached to C-3 and loses approximately 90% of its activity when this is hydrolyzed. This metabolic feature also complicates the pharmacokinetic data, because both active forms are present and have different properties. Cefotaxime should be protected from heat and light and may color slightly without significant loss of potency. Like other third-generation cephalosporins, cefotaxime has less activity against staphylococci but has greater activity against Gram-negative organisms.

Originator

Claforan,Hoechst-Roussel,W. Germany,1980

The Uses of Cefotaxime

Cefotaxime has a broad spectrum of antibicrobial use. It acts bactericidally. It is highly active with respect to Gram-negative microorganisms (E. coli, Citrobacter, Proteus mirabilis, P. indole, Providencia, Klebsiella, Serratia), and a few strains of Pseudomonas, H. influenzae that are resistant to other antibiotics. Cefotaxime is less active with respect to streptococci, pneumococci, meningococci, gonococci, and bacteroides. It is resistant to the majority of beta-lacatamases of Gram-positive and Gram-negative microorganisms.
This drug is used for severe bacterial infections caused by microorganisms that are sensitive to the drug such as peritonitis, sepsis, abdominal infections, infections of the pelvis minor, infections of the lower respiratory tract, urinary tract, bones, joints, skin, soft tissues, and infected wounds and burns. Synonyms of this drug are claforan, zarivis, and others.

The Uses of Cefotaxime

Cephalosporin antibiotic

The Uses of Cefotaxime

Cefotaxime is an antibiotic with broad spectrum activity against Gram positive and Gram negative bacteria.

Background

Cefotaxime is a third-generation cephalosporin antibiotic. Like other third-generation cephalosporins, it has broad spectrum activity against Gram positive and Gram negative bacteria. In most cases, it is considered to be equivalent to ceftriaxone in terms of safety and efficacy. Cefotaxime sodium is marketed under various trade names including Claforan (Sanofi-Aventis).

Indications

Used to treat gonorrhoea, meningitis, and severe infections including infections of the kidney (pyelonephritis) and urinary system. Also used before an operation to prevent infection after surgery.

What are the applications of Application

Cefotaxime is an antibiotic with broad spectrum activity against Gram positive and Gram negative bacteria

Definition

ChEBI: Cefotaxime is a cephalosporin compound having acetoxymethyl and [2-(2-amino-1,3-thiazol-4-yl)-2-(methoxyimino)acetyl]amino side groups. It has a role as a drug allergen and an antibacterial drug. It is a member of 1,3-thiazoles, an oxime O-ether and a cephalosporin. It is a conjugate acid of a cefotaxime(1-).

Manufacturing Process

A solution of 8 g of sodium bicarbonate in about 20 ml of ethanol was progressively added to 45.55 g of pure 3-acetoxymethyl-7-[2-(2-amino-4- thiazolyl)-2-methoxyiminoacetamido]-ceph-3-eme-4-carboxylic acid in 100 ml of distilled water and another 80 ml of ethanol and 4.5 g of activated carbon were added thereto. The mixture was stirred for 5 minutes and was filtered. The filter was rinsed with ethanol and the filtrate was evaporated to dryness under reduced pressure. The residue was taken up in 100 ml of ethanol and evaporated to dryness again. The residue was dissolved in 100 ml of methanol and the solution was poured into 2 l of acetone. The mixture was vigorously stirred and was vacuum filtered. The recovered product was rinsed with acetone and then ether and dried under reduced pressure to obtain 43.7 g of a white product which rehydrated in air to obtain a final weight of 45.2 g of sodium 3-acetoxymethyl-7-[2-(2-amino-4-thiazolyl)-2- methoxyiminoacetamido]-ceph-3-eme-4-carboxylate.

brand name

Claforan (Sanofi Aventis).

Therapeutic Function

Antibiotic

Antimicrobial activity

The aminothiazoyl and methoximino groups at the 7-amino position confer, respectively, potent activity against many Gram-negative rods and cocci and stability to most β-lactamases. Ps. aeruginosa, Sten. maltophilia and other pseudomonads are often resistant. Brucella melitensis and some strains of Nocardia asteroides are susceptible. Activity against L. monocytogenes and B. fragilis is poor.

Acquired resistance

Many enterobacteria resistant to other b-lactam agents are susceptible, but selection of resistant strains with derepressed chromosomal molecular class C cephalosporinases may occur. Gram-negative bacilli producing variants of the TEM enzymes (pp. 230–231) are resistant.

Pharmacokinetics

Cefotaxime is a third generation intravenous cephalosporin antibiotic. It has broad spectrum activity against Gram positive and Gram negative bacteria. It does not have activity against Pseudomonas aeruginosa. Cefotaxime works by inhibiting bacterial cell wall biosynthesis. A positive feature of cefotaxime is that it display a resistance to penicillinases and is useful to treat infections that are resistant to penicillin derivatives.

Pharmacokinetics

C_max 500 mg intramuscular: 10–15 mg/L after 0.5–1 h
1 g intravenous (15-min infusion): 90 mg/L end infusion
Plasma half-life: c.1 h
Volume of distribution: 32–37 L
Plasma protein binding: c. 40%
Distribution
It is widely distributed, achieving therapeutic concentrations in sputum, lung tissue, pleural fluid, peritoneal fluid, prostatic tissue and cortical bone. In patients receiving 2 g every 8 h, mean CSF concentrations in aseptic meningitis were 0.8 mg/L. Levels of 2–15 mg/L can be found in the CSF in the presence of inflammation after doses of 50 mg/kg by intravenous infusion over 30 min. A single intraventricular dose of 40 mg/kg produced levels at 2, 4 and 6 h of 6.4, 5.7 and 4.5 mg/L, respectively.
Metabolism
About 15–25% of a dose is metabolized by hepatic esterases to the desacetyl form, which may have some clinical importance because of its concentration in bile and accumulation in renal failure. Desacetylcefotaxime has about 10% of the activity of the parent against enterobacteria, less against Staph. aureus. Its half-life in normal subjects is around 1.5 h.
Excretion
Elimination is predominantly by the renal route, more than half the dose being recovered in the urine over the first 24 h, about 25% as the desacetyl derivative. Excretion is depressed by probenecid and declines in renal failure with accumulation of the metabolite. In patients with creatinine clearances in the range 3–10 mL/min, the plasma half-life rose to 2.6 h while that of the metabolite rose to 10 h.

Clinical Use

Cefotaxime is widely used in neutropenic patients, respiratory infection, meningitis, intra-abdominal sepsis, osteomyelitis, typhoid fever, urinary tract infection, neonatal sepsis and gonorrhea.

Side Effects

Minor hematological and dermatological side effects common to group 4 cephalosporins have been described. Superinfection with Ps. aeruginosa in the course of treatment has occurred. Occasional cases of pseudomembranous colitis have been reported.

Synthesis

Cefotaxime, |á-O-methyloxime acetate (6R, 7R)-7-[2-(2-amino-4-thiazolyl)- glyoxylamido]-3-(hydroxymethyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-2-carboxylic acid (32.1.2.56), is synthesized by acylating of 7-aminocephalosporanic acid with 2-(2-amino- 4-thiazolyl)-2-methoxyiminoacetic acid, which is protected at the amino group by a trityl protection (32.1.2.54). After removing the trityl protection from the resulting product (32.1.2.55) with dilute formic acid, the desired cefotaxime (32.1.2.56) is formed. The ethyl ester of 2-(2- amino-4-thiazolyl)-2-methoxyminoacetic acid necessary for this synthesis, as well as for the synthesis of a number of other antibiotics of the cephalosporin series, is synthesized from acetoacetic ester. Nitrosation of acetoacetic ester with nitrous acid gives isonitrosoacetoacetic ester (32.1.2.49). O-Methylation of the hydroxyl group of obtained product with dimethylsulfate in the presence of potassium carbonate gives ethyl 2-(methoxyimino)acetoacetate (32.1.2.50).
Brominating the resulting product with bromine in methylene chloride in the presence of p-toluenesulfonic acid gives 4-bromo-2-methoxyiminoacetoacetic ester (32.1.2.51). Reacting this with thiourea according to the classic scheme of preparing of thiazoles from |á- bromocarbonyl compounds and thioamides gives the ethyl ester of 2-(2-amino-4-thiazolyl)-2- methoxyiminoacetic acid (32.1.2.52). Reacting this with triphenylchloromethane in the presence of triethylamine results in a trityl protection of the amino group, forming the ethyl ester of 2-(2-tritylamino-4-thiazolyl)-2-methoxyminoacetic acid (32.1.2.52), which is hydrolyzed to the acid (32.1.2.54) using sodium hydroxide. The resulting acid (32.1.2.54), as was already stated, is used for acylating of 7-aminocephalosporanide acid in the presence of dicyclohexylcarbodiimide, giving tritylated cefotaxime, |á-O-methyloxime acetate 7-[2-(2- tritylamino)-4-thiazolyl-glycoxylamido]-3-(hydroxymethyl)-8-oxo-5-thia-1-azabicyclo [4.2.0]oct-2-en-2-carboxylic acid (32.1.2.55). Finally, removing the trityl protection from the synthesized product (32.1.2.55) using dilute formic acid gives cefotaxime (32.1.2.56).

Drug interactions

Potentially hazardous interactions with other drugs
Anticoagulants: effects of coumarins may be enhanced.

Metabolism

Approximately 20-36% of an intravenously administered dose of 14C-cefotaxime is excreted by the kidney as unchanged cefotaxime and 15-25% as the desacetyl derivative, the major metabolite. The desacetyl metabolite has been shown to contribute to the bactericidal activity. Two other urinary metabolites (M2 and M3) account for about 20-25%. They lack bactericidal activity.

Metabolism

After partial metabolism in the liver to desacetylcefotaxime and inactive metabolites, elimination is mainly by the kidneys and about 40-60% of a dose has been recovered unchanged in the urine within 24 hours; a further 20% is excreted as the desacetyl metabolite. Relatively high concentrations of cefotaxime and desacetylcefotaxime occur in bile and about 20% of a dose has been recovered in the faeces. Probenecid competes for renal tubular secretion with cefotaxime resulting in higher and prolonged plasma concentrations of cefotaxime and its desacetyl metabolite