Cephalosporins Pharmacology: 1st to 5th Generations, Mnemonics, Indications and Adverse effects

Cephalosporins are antimicrobials grouped into five generations based on their spectrum of coverage against gram-positive and gram-negative bacteria as well as their temporal discovery. First-generation cephalosporins have coverage against most gram-positive cocci as well as gram-negative bacteria, e.g., Escherichia coli (E. coli), Proteus mirabilis, and Klebsiella pneumoniae. Second-generation cephalosporins have coverage against Haemophilus influenza (H. influenza), Moraxella catarrhalis, and Bacteroides spp. Third-generation cephalosporins have less coverage against most gram-positive organisms but have increase coverage against Enterobacteriaceae, Neisseria spp., and H. influenza. Fourth-generation cephalosporins have similar coverage as third-generation cephalosporins but with additional coverage against gram-negative bacteria with antimicrobial resistance, e.g., beta-lactamase. Fifth-generation cephalosporins have coverage against methicillin-resistant staphylococci and penicillin-resistant pneumococci. First-generation cephalosporins include cefazolin, cephalothin, cephapirin, cephradine, cefadroxil, and cephalexin. First-generation cephalosporins have active coverage against most gram-positive cocci such as staphylococci spp.and streptococci spp.while having minimal coverage against gram-negative bacteria. Gram-negative bacteria that are more susceptible to first-generation cephalosporins are Proteus mirabilis, E. coli, and Klebsiella pneumoniae. Oral first-generation cephalosporins are commonly prescribed to use against uncomplicated skin and soft tissue infections such as cellulitis and abscesses commonly due to a staphylococci spp. or streptococci spp. infection. Additionally, clinicians can also use them for bone, respiratory tract, genitourinary tract, biliary tract, bloodstream infection, otitis media, and surgical prophylaxis. In fact, cefazolin is the cephalosporin of choice for surgical prophylaxis. Check our website for more medical lecture notes at https://medcrine.com Follow us on twitter @medcrine Facebook at www.fb.me/medcrine Pinterest at pinterest.com/medcrine Telegram at t.me/medcrine email us on info@medcrine.com