L 1-2 Intro to Chemotherapy Flashcards
(20 cards)
What is the function of TNF-alpha
Produced by macrophages
Causes fever, cachexia, apoptosis, inflammation, inhibits growth of tumors and viral replication
An acute phase reaction protein
What are some of the differences between human and bacterial cells that are used for treatment?
Cell wall
50s/30s ribosomes–remember however that human mitochondria have similar ribosomes that may be affected
What are the major groups of drug mechanisms that are used against bacteria?
ICWS
50s/30s protein synth inhibitors
DNA synth inhibition–DNA gyrase or polymerase
What are ways drug resistance can be acquired by bacteria?
Spontaneous mutations that are then passed vertically to progeny
Horizontal transmission by:
1) Transformation: uptake of free DNA, colon common location because many dead/dying bac., mech for penicillin resistance in Pneumococci & Neisseria
2) Transduction: bacteriophage mediated, important for Staph. aureus
3) Conjugation: sex-pilus, primarily g(-), Shigella, Enterobacteriaceae
Mechanism of Action and Resistance for:
Macrolides
MOA: 50s translocation
MOR: methyltransferases alter binding site
Mechanism of Action and Resistance for:
Chloramphenicol
MOA: 50s transpeptidation
MOR: inactivating acetyltransferases
Mechanism of Action and Resistance for:
Aminoglycosides
MOA: 30s, blocks initiation, elicits premature termination, incorporates incorrect AA
MOR: acetyl, phosphoryl, adenylyl conjugation
Mechanism of Action and Resistance for:
Tetracyclines
MOA: 30s, prevent binding of incoming charged tRNA
MOR: pump out
Mechanism of Action and Resistance for:
Fluoroquinolones
MOA: inhibiting topoisomerase
MOR: change in sensitivity of TI, pump out
Mechanism of Action and Resistance for:
Rifampin
MOA: inhibits DNA dependent RNA polymerase
MOR: change in enzyme
Mechanism of Action and Resistance for:
Sulfonamides
MOA: inhibition of folic acid synth
MOR: decrease sensitivity of target enzymes, increased formation of PABA, use of exogenous folate
Mechanism of Action and Resistance for:
Beta Lactams
MOA: inhibition of cell wall synth
MOR: penicillinase, modification of PBP’s, change of porins
Mechanism of Action and Resistance for:
Vancomycin
MOA: inhibition of peptidoglycan chain elongation
MOR: change in pentapeptide, D-ala D-ala lactate
Name the bactericidal agents
Aminoglycosides Bacitracin Beta-lactams Daptomycin Isoniazid Ketolides Metronidazole Polymyxins Pyrazinamide Quinolones Rifampin Tigecycline Vancomycin
Name the bacteriostatic
Chloramphenicol Clindamycin Ethambutol Macrolides Nitrofurantoin Novobiocin Oxazolidinones Sulfonamides Tetracyclines Trimethoprim
Difference between concentration and time dependent bacteriocidal agents
Concentration dependent: increased conc leads to increased killing
Time: changes in conc. have an effect early on, but in the long run rates of death are the same, therefore time is the factor that matters
How do penicillins and aminoglycosides work synergistically?
Penicillins increase the uptake of aminoglycosides making the overall effect more than just the sum of the two individually
How do bacteriocidal and -static agents interact when given together?
-cidal agents often require the cells to be actively growing in order to work, therefore -static agents can inhibit the effects of -cidals
What are the superinfections that can result from the use of broad spectrum antibiotics?
Intestinal candidiasis: treated with Nystatin
Staph Enterocolitis: life-threatening
Pseudomembranous colitis: C. difficile overgrowth, treated by metronidazole or vancomycin
All caused by killing the normal flora that otherwise is protective
How does inflammation change the volume of distribution of the drugs in the body?
Inflammation increases the permeability of the capillaries including in the BBB thereby increasing penetration into the CNS and increasing the volume of distribution
