Antibiotic classes

Betalactams: PCN, cephalosporins, carbapenem, aztreonam

Cephalosporins:

First Generation: GPC (except enterococci, MRSA, and coagulase-negative staphylococci), E. coli, Klebsiella pneumoniae, and Proteus mirabilis.

  • Cefadroxil (Duricef, Ultracef)

  • Cephalothin (Keflin)

  • Cephapirin (Cefadyl)

  • Cephalexin (Keflex)

  • Cephradine (Velocef, Anspor)

  • Cefazolin (Ancef, Kefzol)

Second Generation: Less active against GPC than first-generation cephalosporins; more active against some gram-negative organisms such as H. influenzae, Enterobacter spp. and some Proteus spp.

  • Cefamandole (Mandol)

  • Cefoxitin (Mefoxin)

  • Cefotetan

  • Cefprozil

  • Cefuroxime (Zinacef)

  • Ceforanide (Precef)

  • Cefonicid (Monocid)

  • Cefaclor (Ceclor)

  • Loracarbef (Lorabid)

Third Generation: Expanded activity against Gram-negative rods. Cefotaxime and Ceftriaxone have slightly less activity against GPC than first-generation cephalosporins. Ceftazidime and cefoperazone have even less activity against GPC, but are excellent antipseudomonal agents.

  • Cefotaxime (Claforan)

  • Moxalactam (Moxam)

  • Cefixime (Suprax)

  • Cefoperazone (Cefobid)

  • Ceftizoxime (Ceftizox)

  • Ceftazidime (Fortaz)

  • Tazidine

  • Ceftriaxone (Rocephin)

  • Cefipodoxime

  • Claforan

  • Cefdinir (Omnicef)

Fourth Generation:

  • Cefepime (Maxipime): active against gram positives (including MRSA) and gram negatives (including Pseudomonas); not effective against enterococcus.

Listeria, MRSA, and enterococcus are resistant to all forms of cephalosporins.

PID: cefotetan, cefoxitin + doxycyline. Cefotetan can increase the risk of bleeding by depleting prothrombin. Also has disulfiram like reaction with EtOH.

PCNs

First generation:

  • Benzathine PCN

  • PCN G Benzathine and PCN G procaine (Bicillin C-R)

  • PCN G

  • PCN V

  • Procaine PCN

Second-generation: Penicillin resistant penicillins (PRPs). Not effective against MRSA or enterococcus. MRSA = resistant to oxacillin.

  • Dicloxacillin

  • Naficillin

  • Oxacillin

Third generation:

  • Amoxicillin

    • Hemophilus inf, E. coli, Listeria, Proteus, Salmonella

  • Augmentin

  • Ampicillin

  • Unasyn

Fourth generation:

  • Piperacillin, ticarcillin, azlocillin, mezlocillin: Covers GNB (E. coli, proteus), from enterobacteriacea group and pseudomonas. Not very effective against anaerobes. Always used with beta-lactamase inhibitor (clavulanate or tazobactam).

    • Best initial Tx fro cholecystitis, ascending cholangitis, pyelonephritis, bacteremia, HAP, VAP, neutropenic fever

  • Piperacillin/tazobactam (Zosyn)

  • Timentin

Quinolones (ciprofloxacin, gemifloxaxin, levofloxacin, moxifloxacin). Best CAP, GNB-pseudomonas.

Cipro for cystitis and pyelo.

Moxi does not enter the urine in high conc

Diverticulitis and GI inf: cipro, gemi - but also needs metronidazole for anaerobic coverage. Moxifloxacin covers anaerobes; can be use as a single agent to treat diverticulitis.

SE: bone growth, tendon rupture

First generation

  • Naldixic acid (NegGram)

Second generation

  • Ciprofloxacin

  • Enoxacin

  • Lomefloxacin

  • Norfloxacin

  • Ofloxacin

Third generation

  • Levofloxacin (Levaquin)

Fourth generation

  • Gemifloxacin

  • Moxifloxacin (Avelox)

Aminoglycosides synergistic with beta-lactam ABx for stap. enterococci. No effect on anaerobes (needs O2 to work). Nephrotoxicity/ototoxicity

    • Amikacin

    • Gentamicin

    • Streptomycin

    • Tobramycin

Carbapenems

    • Ertapenem (Invanz)

    • Imipenem/cilastatin (Primaxin)

    • Meropenem

Macrolides

    • Azithromycin

    • Clarithromycin

    • Dirithromycin

    • Erythromycin

Tetracyclines

    • Doxycycline

    • Minocycline

    • Tetracycline

Glycopeptide

    • Vancomycin

Ketolide

    • Telithromycin (Ketek)

Monobactam

  • Aztreonam is a synthetic monocyclic beta-lactam antibiotic (a monobactam). Aztreonam has strong activity against susceptible gram-negative bacteria, including Pseudomonas aeruginosa. It has no useful activity against gram-positive bacteria or anaerobes. It is known to be effective against a wide range of bacteria including Citrobacter, Enterobacter, E. coli, Haemophilus, Klebsiella,Proteus, and Serratia species

    • Nitrofurantoin has one indication: cystitis in pregnancy

    • MRSA: vanco, linezolid (reversible BM toxicity), dapto (↑CPK); tigecycline

    • Minor MRSA skin inf: TMP-SMX, clindamycin, doxycycline

    • Anaerobes:

      • Oral PCN VK, ampicillin, amoxicillin, clindamycin - coverage above diaphragm.

      • GI/Abd: metronidazole

    • GNB: (citrobacter, enterococcus, E.coli, Klebsiella, pseudomonas, proteus).