1. Clinical Cases Beta-Lactam Answers

2. Case 1 What antibiotic would you recommend for intravenous therapy in a 40yo BM with a Staphylococcus aureus (MSSA) bacteremia? Nafcillin or oxacillin – What if the patient had a penicillin allergy (rash)? cefazolin – What if the patient had a penicillin allergy (anaphylaxis)? vancomycin – What if the bacteria instead was MRSA? NKDA vancomycin or linezolid (others possible)

3. Case 2 A 22yo WF presents with a cellulitis. – What would you recommend for an oral antibiotic to cover MSSA and Streptococcal species? NKDA dicloxacillin or cephalexin or cefadroxil

4. Case 3 A 55yo WM develops an Enterococcus faecalis endocarditis. What IV antibiotics would you recommend? NKDA Penicillin G Potassium (or Sodium) (+ aminoglycoside) or Ampicillin (+ aminoglycoside)

5. Case 4 CC is a 65yo WM develops an intrabdominal infection s/p surgery for colon cancer. You would like broad coverage (gram +, gram -, anaerobes). What would you recommend? NKDA Carbapenem or beta-lactam/beta-lactamase inhibitor combo or cefoxitin or cefotetan

6. Case 5 A 70yo WF is admitted to the hospital for CHF. After being in the hospital for 5 days, you now suspect a superimposed hospital-acquired pneumonia. What would you recommend for gram negative coverage including Pseudomonas aeruginosa? Drugs of choice: Cefepime or ceftazidime or piperacillin/tazobactam or ticarcillin/clavulanate Others could use: Aztreonam or carbapenem (except ertapenem)

7. Case 6 A 2yo WM presents to the pediatrician with fever and bilateral ear pain for 5 days. Otitis media is diagnosed. You would like to treat for for possible resistant Streptococcus pnemoniae. What do you recommend? NKDA Amoxicillin 90mg/kg/day – What if the patient had a penicillin allergy (rash)? Cephalopsorin (generally for Steptococcus pneumoniae, a 2 nd or 3 rd generation would be used over a 1 st generation because of resistance) such as cefdinir, cefpodoxime, cefprozil, cefuroxime axetil)

8. Case 7 A 25yo BF is seen by the PA for a 5 day history of fever and sore throat. A rapid strept test is positive. What antibiotic would you recommend? NKDA Strept throat caused by Group A Streptococcus Drug of choice: Penicillin VK Others: amoxicillin or ampicillin – Should this antibiotic be taken with or without food? (penicillins except amoxicillin can be bound by food proteins and inactivated by acid) Penicillin VK and ampicillin on empty stomach (1h before or 2 h after eating) Amoxicillin—with or without food

9. Case 8 A 70yo WM with a history of COPD is admitted to the hospital for a COPD exacerbation. Sputum cultures reveal beta-lactamase positive hemophilus influenzae. What would you recommend? NKDA – Name the penicillin/beta-lactamase inhibitor combinations. Amoxicillin/clavulanic acid (Augmentin®) PO Ampicillin/sulbactam (Unasyn®) IV Ticarcillin/clavulanic acid (Timentin®) IV Piperacillin/tazobactam (Zosyn®) IV – What other bacteria produce a beta-lactamase? Beta lactamase producing organisms Haemophilus influenza, Proteus, Klebsiella, E. Coli, Moraxella catarrhalis, N. gonnorrhea Staphylococcus aureus Bacteroides