Anti-infective Drugs Part 1

Anti-infective Key Points

  • Broad-spectrum vs. narrow-spectrum antibiotics
  • Antimicrobials treat bacterial, viral, and fungal infections
  • Culture and sensitivity specimens should be collected prior to initiation of therapy.
  • Adverse reactions include:
  • Hypersensitivity & anaphylaxis
  • Superinfection
  • Organ toxicity (ototoxic, nephrotoxic
  • Superinfection
  • ñ warfarin activity
  • ò efficacy of oral contraceptives



Expected Action:
β-lactam – destroys bacteria by weakening cell wall

Therapeutic Uses:

Med of choice for G+ cocci (Strep pneumoniae, S. viridans, S. pyogenes)

Med of choice for syphilis

First choice for meningitis

Prophylaxis against bacterial endocarditis

Extended spectrum against Pseudomonas, Proteus, Klebsiella

Adverse Effects:

Anaphylaxis / Renal Impairment / Hyperkalemia (w ñ doses)


Allergies to Penicillin, Cephalosporin, or Imipenem / Kidney Dysfunction


VAminoglycosides / òη Oral Contraceptives


Take orals ĉ H2O, ŝ food (some may be taken ĉ food)

Drug List

Penicillin G

Augmentin (amoxicillin-clavulanate) – Broad spectrum

Nafcillin – Antistaphylococcal

Carbenicillin – Antipseudomonas



Expected Action:

  • β-lactam – destroy bacteria by destroying cell wall

Four generations, each is:ñη against G and anaerobes –more resistant to lactamase – more able to reach CSF

Therapeutic Uses:

Broad spectrum with ñTI for postop infections, meningitis, pelvic infections


Adverse Effects:

Anaphylaxis / Bleeding / Thrombophlebitis / Pain ĉ IM / cross allergies to penicillins / AA-pseudomembranous colitis


  • Allergies to Penicillin / Kidney Dysfunction

Caution with anticoagulants, antiplatelets, and thrombolytics


EtOH intolerance (disulfiram reaction) / Probenecid ò renal excretion


Take ĉ food

Drug List

Cephalexin (Keflex)

Cefaclor (Ceclor)

Cefatriaxone (Rocephin)

Cefepime (Maxipime)

Cephapirin (Cefadyl)

Cefotetan (Cefotan)

Cefotaxime (Claforan)




Expected Action:

β-lactam – destroy bacteria by destroying cell wall

Therapeutic Uses:

Broad spectrum effective for serious infections such as pneumonia, peritonitis, and UTIs. P. aeruginosa develops resistance (use combo) – [broadest spectrum available]

Adverse Effects:

Allergy / GI symptoms / Superinfection


Caution with renal impairment

Med list –

Imipenem (Primaxin)

Meropenem (Merrem IV)




Expected Action:

β-lactam – destroy bacteria by destroying cell wall

Therapeutic Uses:

MRSA / Antibiotic-associated pseudomembranous colitis by C. difficile

Adverse Effects:

Ototoxicity / Infusion Rxn (red man syndrome) / Thrombophlebitis


  • Caution with renal impairment
  • Infuse over 60 minutes

Very low therapeutic index


Med List

Vancomycin (Vancocin)

Aztreonam (Azactam)

Fosfomycin (Monurol)

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