Zusammenfassung der Ressource
Sulphonamide Antibacterial Agent
- Drug Names
- Code Name
- Chemical Name
- Generic/Non-Proprietary
Name
- Trade Name
- Gram Test
- Heteroaromatic purple
stain mixed with
bacteria
- Sticks to outer membrane
- Decolourisation with organic solvent
- Gram Positive: Purple
- Gram Negative: Red
- Mode of Action
- Prontosil
- Azodye
- Prodrug; reduced to
sulphanilamide.
- Prodrug
- Compound metabolised in vivo to
active form of drug.
- SAR
- Para-Amino
essential
(primary!)
- Aromatic Ring and
Sulphonamide essential
- Sulphonamide
primary or
secondary only
- R' only modifiable.
- Improved Sulpha Drugs
- Sulphanilamide
- Poorly water soluble
- Toxic via
crystallisation
in
kidneys
- Second Generation
- Improved
solubility via
increased
polarity
- pKa close to that
of most of the
body.
- Site of Action
- Dihydropterase
Synthase
- Involved in
folic acid
biosynthesis
- Folic Acid
- Essential for 1-Carbon
unit transport of all
oxidation states.
- Required for DNA
synthesis.
- Competitive Inhibitors
- Sulphanilamide competes with PABA
for dihydropterate synthase.
- Bacterial DHFR different
in structure than
human's
- Trimethoprim -
competitive inhibitor
of DHFR
- Septrin
- Synergistic
- Trimethoprim and
Sulphamethoxazole
- Example of: Anti-metabolite and
Bacteriostatic Drug