Exam 4-2 Antibiotics Part 2 Flashcards Preview

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Flashcards in Exam 4-2 Antibiotics Part 2 Deck (23):
1

Antibiotic Therapy: Concepts

*Multidrug resistance
*Therapeutic drug monitoring
*Minimum inhibitory concentration (MIC)
*Time-dependent killing

2

Antibiotic Therapy: concepts-Concentration-dependent killing

*Once-daily vs. multi-daily dosing
*Peak and nadir (trough) blood levels
*Synergistic effects
*Post-antibiotic effect (PAE)

3

Antibiotic Therapy: Toxicities- Ototoxicity

*Temporary or permanent hearing loss, balance problems

4

Nephrotoxicity

*Varying degrees of reduced renal function
*Rising serum creatinine clearance

5

Antibiotic Therapy: Monitor for:

*nadir levels every 5 to 7 days while on therapy as ordered
*serum creatinine levels at least every 3 days as an index of renal function

6

Aminoglycosides:

*gentamicin (Garamycin)
*neomycin (Neo-fradin)
*tobramycin (Nebcin)
*amikacin (Amikin)
*kanamycin
*stretomycin

7

Aminoglycosides: Characteristics

*Natural and semisynthetic
*Produced from Streptomyces
*Poor oral absorption; no PO forms
*Very potent antibiotics with serious toxicities
*Bactericidal; prevent protein synthesis
*Kill mostly gram-negative; some gram-positive

8

Aminoglycosides: Indications

*Used to kill gram-negative bacteria such as Pseudomonas spp., E. coli, Proteus spp., Klebsiella spp., Serratia spp.
*Often used in combination with other antibiotics for synergistic effects
*Certain gram-positive infections that are resistant to other antibiotics

9

Aminoglycosides are poorly-

absorbed through the GI tract and administered parenterally
*Exception: neomycin
-Given orally to decontaminate the GI tract before surgical procedures
-Also used as an enema for this purpose

10

Aminoglycosides cause serious

toxicities
-nephrotoxicity (renal damage)
-ototoxicity (auditory impairment and bestibular eighth cranial nerve)
*Must monitor drug levels to prevent toxicities

11

Fluoroquinolones

*ciprofloxacin (Cipro)
*norfloxacin (Noroxin)
*levofloxacin (Levaquin)
*moxifloxacin (Avelox)

12

Fluoroquinolones: Characteristics

*Excellent oral absorption
*Absorption reduced by antacids
*Effective against gram-negative organisms and some gram-positive organisms

13

Fluoroquinolones: Mechanism of Action

*Bactericidal
*Alter DNA of bacteria, causing death
*Do not affect human DNA

14

Fluoroquinolones: Indications

*Gram negative bacteria such as pseudomonas
*Respiratory infections
*Bone and joint infections
*GI infections
*Skin infections
*Sexually transmitted diseases
*Anthrax

15

Other Antibiotics

*clindamycin (Cleocin)
*linezolid (Zyvox)
*metronidazole (Flagyl)
*nitrofurantoin (Macrodantin)
*quinupristin and dalfoprisitin (Synercid)
*daptomycin (Cubicin)
*vancomycin (Vancocin)

16

clindamycin (Cleocin)

*Used for chronic bone infections, GU infections, intraabdominal infections
*May cause pseudomembranous colitis

17

linezolid (Zyvox)

*New class; oxazolidinones
-Used to treat vancomycin resistant Enterococcus faecium (VREF, VRE), hospital-acquired skin and skin structure infections, including those with MRSA

18

metronidazole (Flagyl)

*Used for anaerobic organisms
*Intraabdominal and gynecologic infections
*Protozoal infections
*EtOH intolerance

19

nitrofurantoin (Macrodantin)

*Primarily used for UTI's (E. coli, S. aureus, Klebsiella spp., Enterobacter spp.)
*Use carefully if renal function is impaired
*Drug concentrates in the urine
*Keep patient well hydrated
*May cause fatal hepatotoxicity

20

quinupristin and dalfopristin (Synercid)

*30:70 combination, work synergistically
*Used for bacteremia and infections caused by vancomycin-resistant Enterococcus (VRE) and other complicated skin infections

21

daptomycin (Cubicin)

*New class: lipopeptide
-Used to treat complicated skin and soft-tissue infections

22

vancomycin

*Natural, bactericidal antibiotic
*Interferes with cell wall synthesis
*Treatment of choice for MRSA and other gram-positive infections
*Must monitor blood levels to ensure therapeutic levels and prevent toxicity
*May cause ototoxicity and nephrotoxicity
*Should be infused over 60 minutes
*Rapid infusions may cause hypotension

23

vancomycin may cause

Red man syndrome
-flushing/itching of the head, neck, face, upper trunk
-Antihistamine may be ordered to reduce these effects
Ensure adequate hydration (2 L fluids/24 hr) if not contraindicated to prevent nephrotoxicity