Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Exam 8: Miscellaneous Antibiotics > Flashcards

Exam 8: Miscellaneous Antibiotics Flashcards

1
Q

What drug is not in the lecture notes that we need to know?

A

Fosfomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is Vancomycin usually administered?

A

IV

Can be given orally for GI infections (it is poorly absorbed through the GI tract)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the tissue distribution of Vancomycin?

A

Widely distributed

Can penetrate BBB (good for meningitis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is Vancomycin eliminated?

A

though the kidneys

Adjust dose with renal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mechanism of action of Vancomycin? Static or cidal?

A

-cidal
Inhibits bacterial cell wall synthesis
Binds to the D-alanyl-D-alanine portion of the peptidoglycan pentapeptide (same result as drugs that bind to PBP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the general spectrum of Vancomycin?

A

Really good at killing gram positive bacteria (staph, strep, clostridium)
Worthless against gram negatives (too big to fit through gram negative porin channels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What bugs have concerning resistance to Vancomycin? Mechanism?

A 
Enterococci
Bacterial enzymes (encoded by Van genes, plasmid) replace the D-alanyl-D-alanine end of the polypeptide, which don't permit adequate binding to the target.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are 3 types of Van phenotypes?

A

Van A- inducible resistance to Vanco and teicoplanin
Van B- lower resistance, to Vanco only
Van C- Constitutive resistance to Vanco

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What causes intermediate vanco resistance in Staph. aureus?

A

Thick walls and false drug targets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What causes high level resistance to vanco in Staph. aureus?

A

Van A transposon form Enterococcus faecalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are clinical uses of Vancomycin? (5)

A
  1. Serious MRSA staph infections (also pneumonia with MRSA)
  2. Gram positive infections in patients allergic to Penicillins and Cephalosporins
  3. C. diff (orally administered)
  4. Staph. meningitis
  5. Included with 3rd gen Cephalosporin to treat Strep pneumo meningitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Adverse effects of Vancomycin

A

Ototoxicity (especially with coadministration of aminoglycosides)
Nephrotoxicity (especially with coadministration of ahminoglycosides or cephalosporins)
Red Neck Syndrome- Rapid infusion can cause flushing due to histamine release (not a true allergic reaction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where does Clindamycin penetrate well? Not well?

A

Penetrates most tissues well
Penetrates abscessed well
Does not penetrate BBB (can still treat cerebral toxoplasmosis somehow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how is clindamycin excreted?

A

metabolized by liver (adjust dose for liver failure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the mechanism of Clindamycin?

A

Binds 50S ribosomal subunit

Bacteriostatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What mechanisms underlie resistance to Clindamycin?

A
  1. Modified 50S subunit (mutations)

2. Enzymatic methylation of 50S subunit (as seen with macrolides)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What if you get a positive D test?

A

Dont use Clindamycin for a serious infection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are 3 types of bugs Clindamycin is good at treating?

A
  1. Staph
  2. Strep
  3. ANAEROBES!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are uses of Clindamycin?

A
  1. Anaerobic infections (abscesses outside the CNS)
  2. In combo with other drugs in penetrating wounds of the abdomen
  3. Prophylaxis for endocarditis in high risk patients getting dental procedures (alternative to Amoxicillin due to allergy)
  4. Alternative agent for gram positive and anaerobic infections in patients allergic to penicillins and cephalosporins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a major complication associated with Clindamycin?

A

C. diff (pseudomembranous colitis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is Nitrofurantoin excreted?

A

Super rapidly in the urine (so fast that you don’t see it systemically)
Causes brown urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a contraindication for Nitrofurantoin?

A

Renal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the mechanism of Nitrofurantoin?

A

Bacteriostatic or -cidal depending on the dose (-cidal >100micro grams/mL)
Mechanism: Reduced forms of the drug bind to and damage bacterial DNA

24
Q

What is Nitrofurantoin used to treat?

A

UTIs (acute treatment and chronic prophylaxis)

25
Q

What is the most common adverse effect of Nitrofurantoin?

A

GI Upset

26
Q

Fosfomycin

A

Taken orally in water solution
Excreted by kidneys
Inhibits bacterial cell wall synthesis (-cidal)
Used to treat UTIs
Adverse effects: Headaches, diarrhea, vaginitis

27
Q

Polymyxins B and E Administration and Mechanism

A

E is parenteral only, B can be topical, otic, ophthalmic or parenteral
Parenteral admin is a last resort
They are Cationic Detergents that interact with phospholipids and disrupt bacterial cell walls (killing effect)

28
Q

What bugs are Polymyxins good at treating?

A

Gram negatives

29
Q

Uses of Polymyxins

A

Topical use with neomycin/bacitracin (Neosporin) in skin infections
Urinary bladder irrigation to prevent infections with indwelling catheters
Parenteral admin is last resort in some bad gram negative infections

30
Q

Adverse effects of Polymyxins

A

Nephrotoxicity

Neurotoxicity

31
Q

What are methods of Metronidazole administration?

A

Oral, IV, rectal, Vaginal gel

32
Q

Where can Metronidazole penetrate?

A

CNS (brain abscess)

33
Q

What can Metronidazole do to the urine?

A

Turn it red/brown

34
Q

Metronidazole mechanism

A

Nitro group is reduced, it then binds to bacterial DNA and inhibits synthesis

35
Q

What kinds of bugs can Metronidazole treat well?

A

Anaerobic powerhouse antibiotic

36
Q

Metronidazole Uses

A

anaerobic brain abscesses
B. fragilis
C. diff

37
Q

Adverse effects of Metronidazole

A

Carcinogenic… avoid in breast milk/pregnancy
Peripheral neuropathy
Disulfiram like reaction with alcohol

38
Q

How can Bacitracin NOT be administered? Why?

A

Parenterally

Nephrotoxic

39
Q

Bacitracin mechanism

A

Inhibits bacterial cell wall synthesis

Inhibits transpoty of peptidoglycan subunits

40
Q

Uses of Bacitracin

A

Mostly topical
Open wounds
Eye infections
Oral for C. diff (alternative therapy)

41
Q

Adverse effects of Bacitracin?

A

Nephrotoxicity- renal failure and glomerular necrosis

42
Q

Quinupristin+Dalfopristin

A

Combo used by IV

43
Q

Quinupristin+Dalfopristin (synercid) elimination?

A

Metabolized mostly by liver, biliary excretion

44
Q

Mechanism of action of Quinupristin+Dalfopristin (Synrecid)

A

Binds to 50S subunit (-cidal)

They each bind to a different part of the subunit

45
Q

What are 3 modes of resistance for Quinupristin+Dalfopristin ?

A
  1. Methylation of binding site
  2. Acetylation inactivation of dalfopristin
  3. Efflux pumps
46
Q

Uses for Quinupristin+Dalfopristin

A

Complicated skin infections by staph and strep
MDR serious infections
Bacteremia by Vanco resistant bugs

47
Q

Linezolid Mechanism

A

Binds to 50S subunit

48
Q

What bugs can Linezolid treat?

A

Gram positives (not anaerobes)

49
Q

Uses of Linezolid

A

Infections caused by Vanco resistance enterococcus
Nosocomial pneumonia from Staph aureus/MRSA*
CAP
Complicated and uncomplicated skin infections

50
Q

Use of Linezolid for enterococcus

A

Not first line because it is bacteriostatic for Enterococcus

51
Q

Adverse effects of Linezolid

A

Thrombocytopenia
GI, Headache, Peripheral Neuropathy
Inhibits MAO (don’t give it with SSRIs or Tyramine rich foods or you may cause serotonin syndrome)

52
Q

Daptomycin Mechanism

A

Binds to plasma membrane and causes depolarization leading to cell death

53
Q

Daptomycin elimination

A

mostly renal (adjust dose for renal failure)

54
Q

Used of Daptomycin

A

Complicated skin infections by Staph and Strep
Bacteremia
Endocarditis

55
Q

When don’t we use Daptomycin? Why?

A

Pulmonary infections

Surfactant antagonizes the drug

Pharmacology (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions