meningitis/ventriculitis secondary to N. meningitidis, H. influenzae, S. pneumoniaeAlthough cefotaxime has demonstrated efficacy in these infections, it is not necessarily considered to be the first-line agent. In meningitis, cefotaxime crosses the blood–brain barrier better than cefuroxime. Spectrum of activity
As a β-lactam antibiotic in the third-generation class of cephalosporins, cefotaxime is active against numerous Gram-positive and Gram-negative bacteria, including several with resistance to classic β-lactams such as penicillin. These bacteria often manifest as infections of the lower respiratory tract, skin, central nervous system, bone, and intra-abdominal cavity. While regional susceptibilities must always be considered, cefotaxime typically is effective against these organisms (in addition to many others):
Staphylococcus aureus (not including MRSA) and S. epidermidis
Streptococcus pneumoniae and S. pyogenes
Escherichia coli
Haemophilus influenzae
Neisseria gonorrhoeae and N. meningitidis
Klebsiella spp. Burkholderia cepacia
Proteus mirabilis and P. vulgaris
Enterobacter spp. Bacteroides spp. Fusobacterium spp.Notable organisms against which cefotaxime is not active include Pseudomonas and Enterococcus. As listed, it has modest activity against the anaerobic Bacteroides fragilis. The following represents MIC susceptibility data for a few medically significant microorganisms:

H. influenzae: ≤0.007 – 0.5 µg/mL
S. aureus: 0.781 – 172 µg/mL
S. pneumoniae: ≤0.007 – 8 µg/mLHistorically, cefotaxime has been considered to be comparable to ceftriaxone (another third-generation cephalosporin) in safety and efficacy for the treatment of bacterial meningitis, lower respiratory tract infections, skin and soft tissue infections, genitourinary tract infections, and bloodstream infections, as well as prophylaxis for abdominal surgery. The majority of these infections are caused by organisms traditionally sensitive to both cephalosporins.
However, ceftriaxone has the advantage of once-daily dosing, whereas the shorter half-life of cefotaxime necessitates two or three daily doses for efficacy. Changing patterns in microbial resistance suggest cefotaxime may be suffering greater resistance than ceftriaxone, whereas the two were previously considered comparable. Considering regional microbial sensitivities is also important when choosing any antimicrobial agent for the treatment of infection. Adverse reactions
Cefotaxime is contraindicated in patients with a known hypersensitivity to cefotaxime or other cephalosporins. Caution should be used and risks weighed against potential benefits in patients with an allergy to penicillin, due to cross-reactivity between the classes. The most common adverse reactions experienced are:

Pain and inflammation at the site of injection/infusion (4.3%)
Rash, pruritus, or fever (2.4%)
Colitis, diarrhea, nausea, vomiting (1.4%)

Mechanism of action
Cefotaxime is a β-lactam antibiotic (which refers to the structural components of the drug molecule itself). As a class, β-lactams inhibit bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs). This inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) in the absence of cell wall assembly.