4. Sulphonamides inhibit multiplication of bacteria by acting as
competitive inhibitors of p-aminobenzoic acid in the folic
acid metabolism cycle.
Bacterial sensitivity is the same for the various sulphonamides, and
resistance to one sulphonamide indicates resistant to all.
Most sulphonamides are readily absorbed orally.
However, parenteral administration is difficult, since the soluble
sulphonamide salts are highly alkaline and irritating to the tissues.
The sulphonamides are widely distributed throughout all tissues.
5. High levels are achieved in pleural, peritoneal, synovial, and ocular
fluids.
Although these drugs are no longer used to treat meningitis, CSF
levels are high in meningeal infections.
Their antibacterial action is inhibited by pus.
Sulfadiazine is a synthetic pyrimidinyl sulphonamide derivative,
short-acting bacteriostatic Sulfadiazine inhibits bacterial folic
acid synthesis by competing with para amino benzoic acid.
It is used in combination with pyrimethamine to treat
toxoplasmosis in patients with acquired immunodeficiency
syndrome and in new-borns with congenital infections.
