Sulfonamides Flashcards
1
Q
What structure are all sulfonamides similar to?
A
Para-aminobenzoic acid (PABA)
2
Q
What is PABA a precursor for?
A
folic acid synthesis by bacteria
3
Q
How does sulfonamides interact with PABA?
A
Competes for the enzyme dihydropteroate synthetase
4
Q
Why does sulfonamides not affect host cells?
A
Host cells require preformed folic acid
5
Q
Are sulfonamides static or cidal?
A
Bacteriostatic
6
Q
What is sulfonamides commonly used for?
A
UTIs
7
Q
ADR for sulfonamides?
A
Nephrotoxicity
Kernicterus
Anaphylaxis
Cutaneous Rxns
Hematologic Rxns
Hypersensitivity Rxns
8
Q
What causes Kernicterus?
A
Last months of pregnancy - compete for bilirubin
Results in increased fetal blood levels of unconjugated bilirubin
9
Q
Spectrum of Activity
sulfonamides
A
?
10
Q
Mechanism of resistance
sulfonamides
A
- Overproduction of PABA
- Structural change in the enzyme with decreased affinity for sulfonamide
- Decreased permeability of bacteria to the drug
