Cephalosporins are a very important group of antibiotics in the beta-lactam class. The cephalosporins are semisynthetic antibiotics derived from products of the fungus Cephalo-sporium. Cephalosporins are classified as first, second, third, fourth, and advanced generation, based largely on their ...
Cephalosporins are classified into five "generations" (Table 1) based on their spectrum of antimicrobial activity. Each newer generation of cephalosporins has significantly broader gram-negative antimicrobial spectrum than the preceding generation, and in most cases decreased activity against gram-positive ...
as a part of their chemical structure. Drugs in this class include penicillin G and V, penicillinase-sensitive and penicillinase-resistant penicillins, cephalosporins, carbapenems, and aztreonam.Penicillins, and are more effective againstEnterobacteriaceae; some drugs are active againstPseudomonas...
Reactions belong to the 4 major mechanisms described by Coombs and Gell, whereby type IV reactions have recently been further subclassified. The most frequent reactions are type I, which are IgE mediated, and type IV, which are nonimmediate and T-cell dependent. IgE-specific antibodies may ...
Cephalosporins are very important group of antibiotics in the 尾-lactam class. The cephalosporins are semisynthetic antibiotics derived from products of the fungus Cephalosporium. Cephalosporins have been classified as first, second, third, fourth, and advanced generation, based largely on their ...
Penicillins and cephalosporins belong to the class of drugs known as 尾-lactams. Naturally produced penicillins by Penicillium chrysogenum are classified as 1st generation. The 2nd, 3rd, and 4th generations are all semi-synthetic obtained from chemical synthesis starting from 6-APA. The ...
These agents have been arbitrarily classified into first, second or third 'generations' on the basis of differences in their spectra of antimicrobial activity (usually versus Gram-negative organisms) rather than the time of their introduction. The first generation cephalosporins are indicated in the ...
The ester may be a diphenylmethyl, stannyl or silyl ester. The dipolarophiles are substances which react with groups having a dipole and may be classified as (a) acetylenic, i.e. of structure R1C#CR2, where R1 and R2 may be the same or differe group or atom, e.g. H, cyano, ...