ABX Overview Flashcards
Gram Positives
Staphylococcus
Streptococcus
Enterococcus
Piddly Category – Gram Negative
Haemophilus (H.flu)
Morexella (M.cat)
Morganella/Salmonella/Shigella
Neisseria/Provedentia
Fence Category (PEK)– Gram Negative
Proteus
E.coli
Klebsiella
SPACE BUGS – Gram Negative
Serratia Pseudomonas Acinetobacter Citrobacter Enterobacter
Atypicals
Chlamydia
Mycoplasma
Legionella
Anaerobes
Peptostreptococcus
Bacteroides
Clostridium
What kind of antibiotics are Lethal to susceptible microorganisms?
Bactericidal Agent
What kind of antibiotics are Inhibitory to growth of susceptible microorganisms?
Bacteriostatic Agent
Trimethoprim/Sulfamethoxazole combo is an example of what?
How?
Synergism
Sequential inhibition of folic acid synthesis
Penicillin/Aminoglycoside combo is an example of what?
How?
Synergism
Increased penetration of aminoglycoside as penicillin breaks down cell wall.
Why don’t you ususally use Bacteriostatic/Bactericidal combos?
Antagonism
Most cidal agents require active cell division or protein synthesis for expression of their bactericidal activity, and many of the static agents inhibit these processes.
What is Postantibiotic Effect (PAE)?
Which classes of ABX exhibit it?
- Persistent effect of an antimicrobial on bacterial growth following brief exposure of organisms to a drug.
- Aminoglycosides and fluoroquinolones have been shown to have a high degree of postantibiotic effect.
What type of bacterial killing:
Bacterial killing is dependent on peak concentration
- Postantibiotic effect assists in this concept.
- Aminoglycosides and fluoroquinolones
Concentration Dependent Killing
What type of bacterial killing:
Bacterial killing is dependent on the amount of time the concentrations stay above the MIC during the dosing interval.
- B-lactam antibiotics (Penicillins, cephalosporins)
Time Dependent Killing
What route of administration of ABX do you use for:
Mild to moderate infections?
ORAL
What route of administration of ABX do you use for:
Moderate to severe infections
Patient unable to take oral agents?
INTRAVENOUS
What route of administration of ABX do you use for:
IV access is not obtainable?
INTRAMUSCULAR
How long should a patient be afebrile before considering changing them to oral ABX?
2 days
What’s the catch22 with taking oral erythromycin or ampicillin?
stomach upset if don’t take with food but decreased absorption if you take with food
Which ABX have Urine concentrations GOOD but systemic concentrations NOT good?
Nitrofurantoin
Carbenicillin
What are some examples of when Renal excretion is desired as opposed to hepatic?
Urinary Tract Infection
Hepatitis
What is the Cockroft-Gault Equation?
What does it measure?
[(140-Age) X Weight (kg)]
[(SrCr X 72)]
*Multiply by 0.85 if female
Measures Creatinine Clearance (mL/min)
How would you treat a “SPACE bug” (what is the name of the method and how does it work)?
Box and One Coverage (B-lactam with AG or FQN)
- Cell Wall Inhib = PCN, Ceph, Carbapenem, Monobactam
- DNA gyrase = Fluoroquinolones
- 30 S = Aminoglycosides
- Ace in the Hole = Aztreonam (Anaphylaxis)
- Last Resort = Colistin (last resort)
What penicillins would you consider for use in “Box and One Coverage” method?
PCNS
Piperacillin Pip/Tazobactam
Ticarcillin Ticar/Clauvulanate
What Cephalosporins would you consider for use in “Box and One Coverage” method?
Cephalosporins
Ceftazidime
Cefepime
What Carbapenems would you consider for use in “Box and One Coverage” method?
Carbapenems
Imipenem
Meropenem
Doripenem
What Monobactam would you consider for use in “Box and One Coverage” method?
Monobactam
Aztreonam (when PCN allergy)
What Aminoglycosides would you consider for use in “Box and One Coverage” method?
AminoGlycosides
Gentamycin
Tobramycin
Amikacin
What Fluoroquinolones would you consider for use in “Box and One Coverage” method?
FluoroQuinoloNe
Ciprofloxacin
Levofloxacin
Which ABX:
Prevents cross-linking of peptidoglycan strands by
inhibiting transpeptidases
Penicillins
Cephalosporins
Carbapenems
Aztreonam
Which ABX:
Inhibits peptidoglycan synthetase and polymerization of linear peptide
Vancomycin
Which ABX:
Inhibits 30 S ribosome; Causes misreading of mRNA
Aminoglycosides
Which ABX:
Inhibits peptidyl transferase and peptide band formation
Chloramphenicol
Which ABX:
Inhibits 50 S ribosome
Erythromycin, clindamycin, lincomycin
Which ABX:
Inhibits binding of aminoacyl tRNA to ribosome
•30S ribosome
Tetracyclines
Which ABX:
23 S ribosome
Streptogramins/Linezolid
Which ABX:
Cationic detergent
Polymixin B, Colistin
Which ABX:
Inhibits DNA-dependent RNA polymerase
Rifampin
Which ABX:
Interferes with supercoiling of DNA by action on DNA gyrase (topoisomerase II)
Fluoroquinolones
Which ABX:
Inhibits lipid synthesis
Isoniazid, ethambutol
Which ABX:
Prevents synthesis of folic acid
Sulfonamides, trimethoprim
What ABX are interfered with by Antacids?
Quinolones
Tetracycline
What ABX should you NOT take with Warfarin?
Bactrim
Erythromycin
What ABX should you NOT take with Theophylline?
Ciprofloxacin
What is “Serotonin Storm” what causes it?
Way too much serotonin
drug interaction between Linezolid and SSRIs
What Mechanisms of Resistance are there for Penicillins/Cephalosporins?
B-lactamases
PBP changes
Porin channel changes
What Mechanisms of Resistance are there for Aminoglycosides?
Enzyme inactivating
What Mechanisms of Resistance are there for Macrolides?
Methyltransferases that alter drug binding sites on 50S ribosomal subunit
What Mechanisms of Resistance are there for Tetracyclines?
Transport systems that pump drugs out of the cell
What Mechanisms of Resistance are there for Sulfonamides?
Increased PABA formation &
Target enzyme sensitivity
What Mechanisms of Resistance are there for Fluoroquinolones?
Target enzyme changes &
Drug efflux
Dose related toxicity with Imipenem is…
seizures
Dose related toxicity with Amphotericin is…
nephrotoxicity
Dose related toxicity with Cefazolin is…
Neutropenia
Idiosyncratic reaction with Chloramphenicol is…
Aplastic Anemia
Why should you never prescribe or allow a patient to take something like immodium when they have C. Difficile?
diarrhea stops but is still being produced by toxin; results in pseudomembranous colitis and toxic megacolon
patient ends up needing colectomy
