Chemotherapy Flashcards
Midwestern University PA Pharmacology 560 - Fall 2013 Dr. Korch
why is chemotherapy unique?
- selective toxicity
- selects for resistant strains
- hypersensitivity and organ directed toxicity = problem
- lowers microorganism load
define: selective toxicity
need greater toxicity to parasite than host
if more toxic to host, then no benefit
is maintenance of blood levels more important with bacteriostatic agents or bactericidal agents?
bacteriostatic
how does chemotherapy select for drug resistant strains?
- natural/acquired
- mechanisms
- multiple drug resistance, usu transferred by plasmids
what are the MECHANISMS by which chemotherapy selects for drug resistant strains?
- pathogen/cell fails to absorb drug
- pathogen/cell inactivates drug
- pathogen/cell pumps drug out
- drug target is modified, thus resistant to drug
- increased production of target molecules
- altered metabolic pathway bypasses drug target
how is antimicrobial resistance acquired?
- by a mutation & passed vertically by selection to daughter cells
- by horizontal transfer of resistant determinants from donor cell (usu from bacterial species)
- by transduction
- by transformation
- by conjugation
“____________ resistant strains of pneumococci account for 50% + isolates in Europe and is rising in the US.”
“PENICILLIN resistant strains of pneumococci account for 50% + isolates in Europe and is rising in the US.”
“The worldwide emergence of Haemophilus & gonococci that produce ____________ is a major therapeutic problem.”
“The worldwide emergence of Haemophilus & gonococci that produce BETA LACTAMASE is a major therapeutic problem.”
“____________ is widely distributed among hospitals.”
“MRSA is widely distributed among hospitals.”
“There are strains of ________, _________, & ________ that are resistant to all known drugs.”
“There are strains of ENTEROCOCCI, PSEUDOMONAS, & ENTEROBACTERS that are resistant to all known drugs.”
“____________ is widely distributed among hospitals.”
“MRSA is widely distributed among hospitals.”
“There are strains of ________, _________, & ________ that are resistant to all known drugs.”
“There are strains of ENTEROCOCCI, PSEUDOMONAS, & ENTEROBACTERS that are resistant to all known drugs.”
“Epidemics of multiple drug resistant strains of _________ have been reported in the US.”
“Epidemics of multiple drug resistant strains of M.TUBERCULOSIS have been reported in the US.”
what are common categories of adverse effects of antimicrobial therapy?
- overextension of pharmacologic actions
- organ directed toxicity
- hypersensitivity rxns
what drugs are known for hepatotoxicity?
- tetracyclines
- isoniazid
- erythromycin estolate
- clindamycin
- sulfonamides
- amphotericin B
what drugs are known for renal toxicity?
- cephalosporins
- vancomycin
- aminoglycosides
- sulfonamides
- amphotericin B
what drugs are known for ototoxicity?
- aminoglycosides
- vancomycin
- minocycline (vestibular only)
what drugs are known for visual toxicity?
- ethambutol
- isoniazid
what are idiosyncrasies that can occur in response to drugs?
- hemolytic anemia (sulfonamides, nitrofurantoin)
- photosensitivity (tetracyclines, flouroquinolones, sulfonamides)
what are allergies that can occur in response to drugs?
- anaphylactic shock
- skin rashes
- immune induced blood dyscrasias
- immune hemolytic anemias
what are idiosyncrasies that can occur in response to drugs?
- hemolytic anemia (sulfonamides, nitrofurantoin)
- photosensitivity (tetracyclines, flouroquinolones, sulfonamides)
what are microorganisms common to gram (+) cocci?
- strep pneum/viridans/pyogenes/agalactiae
- staph aureus
- enterococcus
what are microorganisms common to gram (+) bacilli?
- bacillus species
- listeria species
- nocardia species
what are microorganisms common to gram (-) cocci?
- moraxella catarrhalis
- neisseria gonorrhoeae
- meningitidis
