Lecture 5: Antibiotics for CV Infections

Question 1

What are the 4 major risk factors associated with an increased risk of developing acute rheumatic fever?

Answer 1

• Multiple previous attacks of acute RF
• Short intervals btw attacks of acute RF
• Pt’s w/ increased risk exposure to Strep infections (i.e., children, parents, healthcare and daycare workers, military recruits, and college dorms)
• Young age

Question 2

What is the emperic treatment for acute rheumatic fever?

Answer 2

Penicillin G + Gentamicin

Question 3

What is the drug of choice for treating acute RF infection?

Answer 3

Penicillin G

Question 4

If pt with acute RF has penicillin allergy or hypersensitivity to beta lactams what 4 drugs can you give instead?

Answer 4

• Erythromycin, Azithromycin, Clarithromycin = macrolides
• Clindamycin

Question 5

If there are concerns for recurrent acute RF in a patient hypersensitive to beta-lactams what are the 3 prophylactic drug options?

Answer 5

Erythromycin, Azithromycin, Clarithromycin = Macrolides

Question 6

Which AE associated with clindamycin is why you don’t use it for prophylaxis of recurrent acute RF?

Answer 6

Chance of eliciting opportunistic infection of GI tract by C. difficile

Question 7

What is the empiric treatment for infective endocarditis?

Answer 7

Vancomycin (IV) + Gentamicin (or ceftriaxone)

*MUST give vancomycin via IV for systemic effects

Question 8

Which pharmacologic agents can be used to provide symptomatic relief/manage the joint pain and fever associated with acute RF?

Answer 8

NSAIDs like aspirin or naproxen

Question 9

Through which mechanism does Vancomycin act as a cell wall synthesis inhibitor?

Answer 9

Prevents association of D-alanine-D-alanine subunits

Question 10

If IE is due to S. viridans and is highly penicillin-susceptible which 2 Abx can be used?

Answer 10

• Penicillin G

OR

• Ceftriaxone

Question 11

If IE is due to S. viridans and you want to treat w/ shorter course of abx in pt with no pre-existing renal disease what are your 2 options?

Answer 11

• Gentamcin + penicillin G

OR

• Gentamicin + ceftriaxone

Question 12

If IE is due to S. viridans and pt has a mile penicillin (beta-lactam) allergy what are your 2 options for abx?

Answer 12

• Ceftriaxone

Or

• Gentamicin + Ceftriaxone

Question 13

If IE is due to S. viridans and pt has severe penicillin (beta-lactam) allergy, what is the preferred Abx and what is an alternative?

Answer 13

• Preferred = Penicillin desensitization
• Alternative = Vancomycin

Question 14

Briefly describe how penicillin densisitization works; how many units must be given before full dose can be administered?

Answer 14

• 1 unit of drug is given via IV and pt is observed for 15-30 mins
• No reaction = dose gradually increased every 15-30 mins (tenfold or doubling)
• Once 2 million units reached, the remainder of dose can be given.

Question 15

What is the caveat about performing penicillin densensitization on a pt once they leave the hospital or are off tx?

Answer 15

• Drug MUST be physically present to maintain desensitization
• If pt is off drug they will need to be resensitized

Question 16

If IE is due to S. aureus that is MSSA what 2 abx choices are there?

Answer 16

• Nafcillin

or

• Oxacillin

Question 17

If IE is due to S. aureus that is MRSA what 2 Abx can given and which is preferred?

Answer 17

• Preferred = Vancomycin
• Alternative = Daptomycin

Question 18

If IE is due to S. aureus, and pt has a mild penicillin allergy which Abx should be used?

Answer 18

Cefazolin (1st gen. ceph)

Question 19

If IE is due to S. aureus, and pt has severe penicillin allergy which 2 abx can be used?

Answer 19

• Vancomycin

or

• Daptomycin

Question 20

Which Abx should be used in causes where there are complications of a brain abscess accompanying IE?

Answer 20

Nafcillin

Question 21

What is the MOA of Daptomycin?

Answer 21

• Binds to cell membrane via Ca²⁺-dependent insertion of its lipid tail
• Leads to depolarization, K+ efflux, and rapid cell death

Question 22

If IE is due to S. epidermidis and other coagulase-neg. staphylococci, which Abx should be used?

Answer 22

Vancomycin

Question 23

If IE is due to the HACEK group which Abx should be used?

Answer 23

Ceftriaxone

Question 24

If IE is due to Enterococci (mostyl E. faecalis) what Abx combo should be used?

What if pt has penicillin allergy?

Answer 24

• [Penicillin G or Ampicillin or Vancomycin] + gentamicin
• Use vancomycin if pt has penicillin allergy

Question 25

What is the empiric treatment of pericarditis in immunocompetent pt’s?

Need to monitor what?

Answer 25

• NSAID (i.e., Aspirin or Naproxen) + colchicine
• Important to order CRP to track treatment (measures inflammation)

Question 26

What drug is used is severe or refractory cases of pericarditis?

Comes with what risk?

Answer 26

• Corticosteroids (i.e., prednisone)
• Risk to prolong illness or increase chance of relapse

Question 27

What is the MOA of Colchicine which makes it anti-inflammatory?

Answer 27

• Binds tubulin and prevents tubulin polymerization –> microtubules
• Leads to inhibition of leukocyte migration and phagocytosis

Question 28

What are the AE’s associated with Colchicine and more likely via which route of administration?

Answer 28

• Diarrhea and ocassionaly N/V and abdominal pain
• Hair loss, bone marrow depression, periperal neuritis or myopathy
• MORE likely seen with IV vs. oral administration