Antibiotic Cases Nathan P. Samsa, Pharm.D., R.Ph.

Case 1 A 59yo female presents to the ER with community acquired pneumonia. PMH: DM-2, HTN, CRF Labs: –WBC: 14,500 –CrCl: 4.6 –BUN: 71

Case 1 Question What empiric antibiotic(s) would you start this patient on? 1.Cetriaxone 2.Levofloxacin 3.Azithromycin 4.Cetfriaxone + Levofloxacin 5.Ceftriaxone + Azithromycin

Case 1 Answer 5.Ceftriaxone + Azithromycin Key concept here is the CRF. Fluoroquinolones (levofloxacin) are renally eliminated. Ceftriaxone + Azithromycin are hepatically eliminated. Both are standard of care, but it comes down to liver & kidney status.

Case 1 Discussion Shortcut for CrCl: –(140-Age)/SrCr (x0.85 for female) –<50mL/min, drugs need to be adjusted –Patient’s is 15 Azithromycin covers all bugs for pneumonia (atypicals & typicals) except for Strep pneumo, so that is why ceftriaxone is added.

Case 2 A 13 day old neonate has suspected meningitis.

Case 2 Question What empiric antibiotic(s) would you start this patient on? 1.Cetriaxone 2.Cefotaxime 3.Cefotaxime + Ceftriaxone 4.Cefotaxime + Ampicillin 5.Ceftriaxone + Ampicillin

Case 2 Answer 4.Cefotaxime + Ampicillin Ampicillin is added for Listeria monocytogenes coverage Cefotaxime covers the other bugs Why cefotaxime over ceftriaxone? –Ceftriaxone can cause kernicterus in a neonate

Case 3 A woman has a diagnosed case of Pseudomebranous Colitis.

Case 3 Question 1 What antibiotic is the most common cause? 1.Clindamycin 2.Vancomycin 3.Erythromycin 4.Gentamicin 5.Penicillin

Case 3 Answer 1 1.Clindamycin

Case 3 Question 2 Which antibiotic would you treat the above patient first line (with Pseduemembranous Colitis)? 1.Vancomycin 2.Clindamycin 3.Metronidazole 4.Pipercillin/tazobactam 5.Fluconazole

Case 3 Answer 2 3.Metronidazole Both vancomycin and metronidazole are treatments, but metronidazole is 1 st line because: –It’s cheaper –You don’t want to start out with your biggest guns

Case 4 Which agent is safe to give to a neonate? 1.Sulfamexthoxazole/trimethoprim 2.Penicillin 3.Ciprofloxacin 4.Minocycline 5.Chloramphenicol

Case 4 Answer 2.Penicillin SMX/TMP can cause kernicterus Ciprofloxacin can cause tendon rupture Minocycline can cause tooth malformation Chloramphenicol can cause Grey Baby Syndrome

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