Pharmacology - UTI Flashcards
What are the symptoms to cystitis
Frequent urination
Burning after urination
Suprapubic pain
Hematuria or cloudy urine
What are the symptoms to pyelonephritis
Fever Flank pain Chills C-reactive protein Can have cystitis symptoms
What is the difference between cystitis and urethritis
Both have pyuria
Cystitis has bacteriuria on culture and hematuria
Urethritis has no bacteriuria and hematuria
What are the drugs used in acute uncomplicated cystitis
Nitrofurantoin (twice daily for 5 days)
Trimethoprim-sulfamethoxazole (twice daily for 3 days)
Fosfomycin (single dose)
What drug do you avoid in the elderly and why
TMP-SMX
Risk of reducing renal function
What is the mechanism of nitrofurantoin
Reduced by bacterial flavoproteins to reactivate intermediates
Inactivate or alter bacterial ribosomal proteins and other macromolecules
Inhibits protein synthesis, energy metabolism, DNA synthesis, RNA synthesis, cell wall synthesis
Resistance to nitrofurantoin
Lack of acquired bacterial resistance due to multiple mutation of target macromolecules
What enzyme does trimethoprim inhibit
Dihydrofolate reductase
What enzyme does sulfamethoxazole inhibit
Dihydropteroate synthase
What does TMP-SMX block synthesis of
Folate synthesis
Resistance to TMP-SMX
Reduced permeability to sulfonamides
Increased PABA
Produce enzymes that has less selectivity for sulfonamides
What are side effects of any anti-folate drugs (TMP-SMX)
Megaloblastic anemia
Leukopenia
Granulocytopenia
What is the mechanism of fosfomycin
Block the addition of phosphoenolpyruvate to UDP-NAG
Which is the first step in the formation of UDP-NAM, the precursor of NAM
Resistance to fosfomycin
Mutations relating to the transporters
Mutation to MurA
Enzymes that inactivate fosfomycin
What drugs are used for acute complicated cystitis
Fluoroquinolones (3 days)
β-Lactam/cephalosporins (3-7 days)
Mechanism of fluoroquinolones
Quinolones block bacterial DNA synthesis by inhibiting bacterial topoisomerase II (DNA gyrase) and topoisomerase IV
What are the drugs used in acute pyelonephritis
Ciprofloxacin (5 days)
Levofloxacin (7 days)
These two can be given w/w.o. IV fluoroquinolones
TMP-SMX (twice daily for 14 days)
What drugs can be used in pregnant UTI
Amoxicillin�
Cephalexin
Fosfomycin�
When is nitrofurantoin contraindicated in pregnancy and why
First trimester - cardiac birth defects
Near term - hemolytic anemia in G-6PD deficient mothers and fetus
Why are fluoroquinolones contraindicated in pregnancy
Damage articular cartilage
Why are tetracyclines contraindicated in pregnancy
Affect bone formation
When is TMP-SMX contraindicated in pregnancy
TMP - first trimester
SMX - third trimester
Why is trimethoprim contraindicated in pregnancy
Inhibits folate synthesis and may cause neural tube defects
Why are sulfonamides contraindicated in pregnancy
Compete with bilirubin binding to serum albumin and increase free bilirubin levels
Hyperbilirubinemia, jaundice, and kernicterus
