Penicillin - Combinations

• Ampicillin/Sulbactam (Unasyn)
  • IV 3.0 gram q6h
• Ticarcillin/Clavulanic Acid (Timentin)
  • IV 3.1 gram q6h
• Piperacillin/Tazobactam (Zosyn)
  • IV 3.375 gram q6h
  • Good for Pseudomonas auruginosa and Proteus mirabilis
    • 4.5 grams for P. auruginosa
• Amoxicillin/Clavulanic Acid (Augmentin)
  • PO 875 mg bid

 

Tetracyclines

• CA MRSA
• Adverse Effects:
  • Photosensitivity
  • Doxycycline – photo-onycholysis
• CI:
  • Pregnancy/Children – Permanent tooth discoloration
  • Antacids, milk, food, &/or iron limits absorption
  • May cause acute pancreatitis
• Drugs
  • Tetracycline HCL (Short)
  • Methacycline (Intermediate)
  • Doxycycline (long)
    • Erosive esophagitis risk when taken before bedtime
    • May reduce progression of OA as a MMP inhibitor (anti-inflammatory property)
  • Minocycline
  • Tigacycline (Tygacil)
    • HA MRSA & VRE
    • Permanent discoloration of teeth during developmet
    • IV only; 100 mg initial dose, 50 mg q12h

 

Lincosamide – Clindamycin (Cleocin)

• CA MRSA
• Fulminant Strep A (necrotizing fasciitis)
• Staphylococcus aureus resistant to erythromycin on C&S can develop inducible resistance to clindamycin
• Adverse effects:
  • Diarrhea
  • Pseudomembranous colitis
• Preoperatve prophylaxis: 600-900mg 1 hr before surgery
• Good bone penetration/poor CNS penetration

 

Cephalosporins

• 1st generation – “PEcK”
  • Cephalexin, Cephadroxil, Cefazolin (Ancef)
• 2nd generation – “HEN PEcKS”
  • Cefuroxime, cefoxitin
• 3rd generation
  • Cefixime, Cefpodoxime, Ceftriaxone (Rocephin), Ceftazidime, Cefdinir (Omnicef), Fortaz
  • Fortaz: Pseudomonas
  • Omnicef: Staph and Strep
• 4th generation: Cefipime (Maxipime)
• Extendend Spectrum: Ceftobiprole – HA MRSA
• Cefdinir and Cefuroxime – no PCN allergy

 

Carbepenams

• Contra-indicated: PCN allergy

• Primaxin (Imipenem/cilastin) – CI: Seizure
• Merrem (Meropenem) – less likely to cause seizures
• Invanz (Ertapenem) – 1 g q24h (CrCl <30 ml/min: 500 mg q24h; ≥6 hrs prior to hemodialysis) – CI: Seizure – DI: Probenecid
• Doripenem – phase II trials; P aeruginosa

 

Monobactams: Aztreonam (azactam)

• May be given to PCN allergy; no renal toxicity (can be given to may patients on dialysis)

 

Aminoglycosides: Tobramycin, Amikacin, Gentamycin (“TAG”)

• CA MRSA; Peak and Trough recommended; AE: ototoxicity (irreversible), Nephrotoxicity (reversible), Hypokalemia, Hypomagnesia
• Do Not use with diabetics or Myasthenia gravis

 

Vancomycin (glycopeptide):

• 1gram q12 IV (>70 kg) NRDA

• HA MRSA; Oral – Clostridium difficile associated psedomembranous colitis
• Endocartditis prophylaxis for pts allergic to B-Lactams and for “going into infected tissue”
• AE: ototoxicity (reversible), Nephrotoxicity (reversibile), thrombophlebitis, Red man syndrome (histamine release)

 

Macrolides: Azithromycin, Clarithromycin, Erythromycin (“ACE”)

• Major DI: digoxin (↑), HMG CoA reductase inhibitors (↑), Coumadin (↑)
• Erythromycin – Torsades de pointes – inhibitor of CYP3A4
• Azithromycin (zithromax) – 500 mg 1st day, 250 mg qd x 4 days

 

Sulfonamides: Sulfamethoxazole-trimethoprim sulfate (Bactrim or Septra)

• CA MRSA
• Caution: age >50; Extreme: oral sulfonylureas (risk hypoglycemia)
• Enhance marrow suppression in pts on Methotrexate
• Acute pancreatitis

 

Metronidazole (flagyl):

• Pseudomembranous colitis
• AE: peripheral neuropathy, dark brown urine
• 15 mg/kg then 7.5 mg/kg q6h IV; 500 mg tid PO

 

Fluoroquinolones: -floxacin

• false positive opiate test
• Torsades de pointes & ventricular fibrillation
• DI: Antacids, Phenytoin
• Ciprofloxacin
  • CI: pregnancy/children – damage joint cartilage
  • Tendonitis and tendon rupture
  • DI: caffeine, NSAIDs
  • 750 mg po q12h (IV=PO for bone penetration – treat OM)
• Levofloxacin (levaquin)
  • CI: pregnancy/children – damage joint cartilage
  • Post-antibiotic effect
  • Excellent tissue penetration
  • Uncomplicated skin and soft tissue infection
  • 500 mg q24h po or IV
• Moxifloxacin (avelox)
  • Complicated and Uncomplicated skin and Soft tissue infections
  • B. fragilis, Tuberculosis
  • Good soft tissue penetration –good for diabetics w/atherosclerosis

 

Chloramphenicol:

• May be last resort for VRE
• AE: gray baby syndrome, severe bone marrow toxicity, aplastic anemia
• 50-100 mg/kg/day IV div q6h RDA

 

Rifamycin – Rifampin

• CA MRSA – with Bactrim or cipro (300 mg po bid)
• Orange body fluids – discolors contact lenses

 

Streptogramins – Synercid

• VRE, HA MRSA
• Cytochrome P450 3A4

 

Oxazolidinones – Zyvox (linezolid)

• VRE, MRSA, VRSE
• Good oral absorption and bone penetration
• Monitor CBCs weekly – myelosupression, peripheral/optic neruopathy
• Coadminister SSRIs and other antidepressants with caution

 

Cyclic Lipopeptide – Cubicin (Daptomycin)

• Monitor CPK weekly – especially pts on statins (potentiate myopathy)
• 4mg/kg q24h – QD for MRSA and VRSA

 

Glycylcyclines – Tygacil (tigecycline)

• HA MRSA & VRE
• Permanent discoloration of teeth development
• IV only; 100 mg initial dose, 50 mg q12h