Abx III (lecture) Flashcards
What pathway is inhibited by sulfonamides?
folate synth - needed for nucleic acid synth in bacteria
What is the target of sulfonamides?
Dihydropteroate synthase (PABA –> Dihydropteric Acid)
What are the three primary uses of sulfonamides?
UTI, meningitis, pneumocystic pneumonia
What is the big adverse effect of sulfonamides?
Steven Johnson Syndrome
What are the 4 mechanisms of sulfonamide resistance?
Increased PABA production
Decrease synthase sensitivity
Decreased influx
Increased efflux (active)
What is the target of trimethoprim?
Dihydrofolate reductase (DHF –> THF)
What is the spectrum of trimethoprim?
Broad G+ and G-
What are the three adverse effects of trimethoprim?
In folate deficiency: megaloblastic anemia, leukopenia, granulocytopenia
Skin sensitivity in HIV/AIDS
Permanent renal damage in renal disease
What are the 3 mechanisms of resistance to trimethoprim?
Decrease influx
Increased production of DHF reductase
Decreased sensitivity of DHF reductase
What is an absolute contraindication of trimethoprim?
Pregnancy
What is the target of fluoroquinolone?
DNA gyrase (a.k.a. topoisomerase II)
What is the suffix of fluoroquinolones?
“-floxacin”, e.g. ciprofloxacin
What is the spectrum of fluoroquinolone?
Broad G+ and G-
What are the 3 signs of toxic drug interaction with fluoroquinolone?
Seizures, cardiac arrest, respiratory failure
Are fluoroquinolone used in pregnancy or breast feeding?
NO
What are the 3 mechanisms of resistance to fluoroquinolone?
Decreased influx
Decrease affinity to DNA gyrase
Acquisition of topoisomerase IV
What is the spectrum of metronidazole?
anaerobic bacteria and protozoa
What is the mechanism of metronidazole?
Induce DNA damage
What are the 2 drug interactions of metronidazole?
Barbituates induce liver enzymes and metabolism of Met
Met interferes with ETOH met
What are the 4 common side effects of metronidazole?
Headache, nausea, dry mouth, metallic taste
What is the MoA of rifampin?
Inhibit RNA synthesis and RNA polymerase
What is used to treat H. influenzae and menigococci meningitis?
Rifampin
What is used to treat both Neisseria and mycobacteria?
Rifampin
What is a common side effect of rifampin with regard to bodily fluids?
Turn them red
What is the mechanism of resistance to rifampin?
Decreased affinity to RNA polymerase
What is the DoC for traveler’s diarrhea?
Rifampin