| Pharmacodynamics |
Sulfadiazine is a sulfonamide antibiotic. The sulfonamides are
synthetic bacteriostatic antibiotics with a wide spectrum against most
gram-positive and many gram-negative organisms. However, many strains of
an individual species may be resistant. Sulfonamides 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 sulfonamides, and resistance to one sulfonamide
indicates resistance to all. Most sulfonamides are readily absorbed
orally. However, parenteral administration is difficult, since the
soluble sulfonamide salts are highly alkaline and irritating to the
tissues. The sulfonamides are widely distributed throughout all tissues.
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. |
