Inhibitors of DNA Synthesis Flashcards
What are the Fluoroquinolones
Nalidixic acid (1st) Ciprofloxacin (2nd) Levofloxacin (3rd) Moxifloxacin (4th) Gemifloxacin (4th)
What are the Sulfonamides
Sulfacetamide Sulfadiazine Sulfamethoxazole Sulfasalazine Sulfisoxazole
What are the Misc inhibitors of DNA synth
Trimethoprim
Co-trimoxazole
Metronidazole
What is the Urinary Antiseptic
Nitrofurantoin
Relationship between Fluoroquinolone generation and gram
Low gen = More G-
High gen = More G+
Which Fluoroquinolone is good against S. pneumoniae
Levofloxacin
Which Fluoroquinolone is synergistic with beta-lactams
Ciprofloxacin
What are 1st gen Fluoroquinolones for
Uncomplicated UTIs
What are 2nd gen Fluoroquinolones for
Traveler’s Diarrhea (ETEC)
P. aeruginosa in CF
Meningitis prophylaxis
What are 3rd gen Fluoroquinolones for
Prostatitis (E. coli)
STIs (not syphillis)
Acute sinusitis, bronchitis, TB
What are 4th gen Fluoroquinolones for
Monotherapy Community acquired PNA
S. pneumoniae 2nd line outpt, 1rd line inpt
Respiratory quinolones (3rd, 4th)
How do Fluoroquinolones act
Enter bacteria via porins
Inhibit Topo II, IV
What inpt infections can Fluoroquinolones be used for
S. pneumoniae
H. influenza
M. catarrhalis
Atypical pathogens
Don’t give with milk or acid
Fluoroquinolones
What messes with Fluoroquinolone absorption
Divalent cations (Fe, Zn, Ca)
For which Fluoroquinolone do you not have to adjust the dose for in renal dysfunction
Moxifloxacin
Which Fluoroquinolones can cause QT prolongation
3rd, 4th
What can enhance toxicity of Fluoroquinolones
Theophylline
NSAIDS
Corticosteroids
3rd and 4th Fluoroquinolone AE
Increase warfarin, caffeine and cyclosporine levels
Main Fluoroquinolone AE
Tendon rupture
When are Fluoroquinolones contraindicated
Pregnant
Nursing mothers
Everyone <18
General Fluoroquinolone AE
Photosensitivity
GI distress
CNS
Rash
Fluoroquinolone Resistance
Chromosomal mutation in gyrase and topo IV
Expression of efflux pumps
Why are Sulfonamides given in triple therapy
Resistance with alone
How do Sulfonamides work
Inhibit Dihydropteroate Synthase
Decreases folate
Which Sulfonamide can you give for IBD
Sulfasalazine
When can you give Sulfonamides topically
Eyes
Burns
When can you give Sulfonamides orally
Simple UTI
What is the structure of Sulfonamides
PABA analog
When can Sulfonamides accumulate
Renal failure
What can increase Sulfonamide plasma levels
Warfarin
Phenytoin
MTX
Main Sulfonamide AE
Hypersensitivity
Crystalluria
Sulfonamide Contraindications
Infants, newborns (Kernicterus)
Who gets hemolytic anemia with Sulfonamides
G6PD deficiency
General Sulfonamide AE
Photosensitivity
GI distress
Fever, Rash
Sulfonamides Resistance
Altered enzyme
Decreased permeability
Enhanced PABA production
Decreased accumulation
How do Sulfonamides cause kidney damage
Acetylation in liver causes metabolite precipitation at neutral/acid pH
What is TMP used for clinically
UTIs
Bacterial prostatitis (after cipro)
BV
What does TMP do
Inhibit DHF reductase
What goes well with TMP
SMX
Where does TMP hit high conc
Prostate
Vagina
When is TMP contraindicated
Pregnancy
TMP AE
Megaloblastic anemia
Leukopenia
Rash, pruritis
What do you give for TMP leukopenia
Leucovorin
DOC PCP, Uncomplicated UTIs, Nocardiosis, Toxoplasmosis
Co-trimoxazole
What is Co-trimoxazole
TMP + SMX
When is Co-trimoxazole contraindicated
Pregnancy
Co-trimoxazole AE
Stevens-Johnson
GI
Hemolytic anemia
More AE in AIDS
DOC C. Diff
Metronidazole
Aside from C. diff, what’s Metro good for
Anaerobic/mixed intra-abdominal infections
T. vaginalis, BV, Gardnerella vaginalis
Brain abscess
Triple therapy for H. pylori
How does Metro work
Reductive bioactivation of nitro group by ferredoxin
Cytotoxic product
Interfere with nucleic acid synth
How is Metro eliminated
Liver
What are the general Metro AE
GI stomatitis Peripheral neuropathy, HA Dark urine Leukopenia, dizziness, ataxia Opportunistic fungal infections
What is the most notable Metro AE
Disulfiram-like reaction
Can you give Metro in pregnancy
Avoid in 1st trim
Prophylaxis and Tx of lower UTI
Nitrofurantoin
When is Nitrofurantoin contraindicated
Renal failure
Pregnancy at term
Infants
What should you give to at-term pregnancy instead of Nitrofurantoin
Amoxicillin
Where is the only place therapeutic levels of Nitrofurantoin are found
Urine
Nitrofurantoin AE
Anorexia
N/V
Neuropathy
Does Nitrofurantoin have cross reactivity
No
How does Nitrofurantoin act
Reduced by bacteria
Damage DNA