Antimicrobials Flashcards
What is Minimum Inhibitory Concentration (MIC):
Lowest concentration of antibiotic required to prevent growth.
What is minimum Bactericidal Concentration (MBC)
Lowest concentration required to kill bacteria
List bactericidal medications:
- Penicillins
- Cephalosporins
- Aminoglycosides
- Vancomycin
- Quinolones
- Aztreonam
- Imipenem
- Bacitracin
- Polymyxins
List Bacteriostatic medication:
- Tetracyclines
- Erythromycin
- Sulfonamides
- Trimethoprin
- Clindamycin
- Chloramphenicol
List some narrow spectrum antimicrobials:
- Penicillin G
- Erythromycin
- Clindamycin
List some broad spectrum antimicrobials:
- Ampicillin
- Aminoglycosides
- Cephalosporins
- Chloramphenicol
- Tetracyclines
- Quinolones
List some medications that have a concentration dependent killing
- Aminoglycoside
- Fluoroquinolones
List some medications that have a time dependent killing:
- Beta Lactams
- Monobactam (Aztreonam)
- Macrolides (Erythromycin, Clindamycin)
T/F: Continous infusion has shown to be more effective than intermittent boluses for time dependent killing of microbes.
FALSE (Continuous infusion has NOT shown…)
What is post antibiotic effect (PAE):
antibiotics continue to suppress the growth of bacteria even after the antibiotic is no longer detectable
List some common facts about post antibiotic effects:
- Demonstrated for virtually all antimicrobials
- Can be decreased in acidic (infected) media
- During the PAE phase, bacteria are more susceptible to killing by leukocytes
List the mechanisms for acquired resistance to antibiotics:
- decreased permeability
- Increased efflux pumps
- Inactivation
- Modification of the antimicrobial target
- Development of pathways that bypass the target
What is decreased permeability:
-Antibiotics enter the outer membrane of gram - bacteria through specialized channels or porins
Increased efflux is less common, but can be important for what antibiotics:
- Macrolides
- Fluoroquinolones
- beta lactams
What inactivates beta lactams:
beta-lactamases
Target modification in penicillin binding proteins account for methicillin resistance in staphylococcus and penicillin resistance in :
- pneumococci
- enterococci
List the responses of using combo drugs such as antagonism, indifferent, inbetween, additive, synergistic:
- antagonism is 1 + 1 = 0.5
- indifferent is 1 + 1 = 1
- Inbetween is 1 + 1 = 1.5
- Additive is 1 + 1 = 2
- Synergistic is 1 + 1 = 3
What are the general principal of therapeutic antimicrobial use:
- Delivery
- Concentration
- Time period
List the five clinical situations bactericidal therapy is essential for clinical use:
- Cardiovascular
- meningitis and cerebral abscess
- Invasive bacterial infection in severely neutopenic patient
- Osteomyelitis
- Treatment of infected prosthesis without removing the device
Effective antibiotic therapy involves integrating information regarding the:
- Patient
- Invading microbe
- Antimicrobial agents
What antibiotics are safe for use with a pregnant patient:
- penicillins
- cephalosporins
- erythromycin
What antibiotics are okay for use if necessary:
- Aminoglycosides
- Isoniazid
Which medication should be avoided in pregnancy:
- Metranidazole
- ticarcillin
- rifampin
- trimethoprim
- fluoroquinolones
- tetracyclines
What will tetracycline do in pregnancy:
-cause acute fatty necrosis of the liver, pancrease, and possible renal injury
What is the 80 percent of nosocomial infection with respiratory, blood, and urinary tract and name the organism.
-Respiratory is 24%
Staph and gram -
-Blood is 17%
S. epidermidis, S. aureus, and enterococcus
-Urinary is 36%
S. aureus, psuedomonas, E.coli, candida
List from greatest to least the infection associated with central lines from femoral, I.J., and subclavian:
- Femoral
- I.J.
- Subclavian
How long is the treatment for catheters infected with S. Aureus:
2 - 4 weeks
Need for surgical prophylaxis depends on:
- Risk for infection
- Patient related factors
- Bacterial milieu
- Hospital infection rate for varius procedures
- Factors relating to the wound itself
Median sternotomies usually have ___ and are covered by cefazolin.
Gram +
What type of antibiotic would be used for infected tissues or prosthetic cardiac valves for cellulitis and osteomyelitis:
-antistaphylococcal antibiotics
What antibiotics would be used for urinary tract infection with gram - bacilli:
- Fluoroquinolones
- aminoglycosides
- 3rd generation cepholosporins
What is an emerging fluconazole resistant fungal:
-C. albicans
Clindamycin is similar to erythromycin, but is more active against many _____.
Anaerobes
What is a leading cause of gastrointestinal infection:
-Clostridium Difficile
What is the treatment for C. Difficile:
- Metronidazole 1st line
- Vancomycin 2nd line
- Dificid (fidaxomicin)
List the antimicrobials by class:
- Beta Lactams
- Cephalosporins
- Monobactams, Carbapenems
- Macrolides
- Fluoroquinolones
- Tetracyclines
- Aminoglycosides
- Miscellaneous Agents
What antimicrobial affects the cell wall integrity:
B-Lactams
What anitmicrobial affects the DNA synthesis:
Metronidazole
What anitmicrobial affects the DNA gyrase:
-Quinolones
What anitmicrobial affects the RNA polymerase:
-Rifampicin
What anitmicrobial affects the Phospholipid membranes:
-polymyxins
What anitmicrobial affects the Protein synthesis of 30s inhibitors:
- Tetracylines
- Streptomycin
- Spectinomycin
- Kanamycin
What anitmicrobial affects the protein synthesis of 50s inhibitors:
- Erythromycin
- Choramphenicol
- Clindamycin
- Lincomycin
What anitmicrobial affects the Cell wall synthesis:
- D-cycoserine
- Vancomycin
- Bacitracin
- Penicilins
- Cephalosporins
- Cephamycins
What do beta lactams work:
-bind to the penicillin binding protein due to similar structure to D-alanyl-D-alanine
What are some beta lactamse inhibitors:
- Sulbactam
- Tazobactam
- Clavulanic Acid
Facts about penicillins:
ADMINISTRATION:
- PVK is PO
- PCN G is IV/IM
HALF LIFE
0.5 hours
EFFECTIVE AGAINST:
-Strep a and b, some pneumococci, enterococci, H. influenzae, N. meningitis, Treponema pallidum
ADVERSE EFFECTS:
Hypersensitivity, GI upset, diarrhea, JARISCH-HERXHEIMER rxn
-ELIMINATION
renal
T/F: Ampicillin has a wide tissue distribution including the CNS when inflammed.
TRUE
