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
Penicillin
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)
Contraindications:
Allergies to Penicillin, Cephalosporin, or Imipenem / Kidney Dysfunction
Interactions:
VAminoglycosides / òη Oral Contraceptives
Education:
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
Cephalosporins
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
Contraindications:
- Allergies to Penicillin / Kidney Dysfunction
Caution with anticoagulants, antiplatelets, and thrombolytics
Interactions:
EtOH intolerance (disulfiram reaction) / Probenecid ò renal excretion
Education:
Take ĉ food
Drug List
Cephalexin (Keflex)
Cefaclor (Ceclor)
Cefatriaxone (Rocephin)
Cefepime (Maxipime)
Cephapirin (Cefadyl)
Cefotetan (Cefotan)
Cefotaxime (Claforan)
Carbapenems
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
Contraindications:
Caution with renal impairment
Med list –
Imipenem (Primaxin)
Meropenem (Merrem IV)
Monobactams
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
Contraindications/Precautions:
- Caution with renal impairment
- Infuse over 60 minutes
Very low therapeutic index
Med List
Vancomycin (Vancocin)
Aztreonam (Azactam)
Fosfomycin (Monurol)
