Phthalylsulfathiazole
Phthalylsulfathiazole is a sulfonamide broad-spectrum antimicrobial used primarily for treating gastrointestinal infections.
Phthalylsulfathiazole is indicated for treating various intestinal conditions, including dysentery, colitis, gastroenteritis, and for preoperative preparation in intestinal surgery. It may be administered in combination with other antimicrobials such as metronidazole, furazolidone, or neomycin for enhanced efficacy.
Like all antibiotics, phthalylsulfathiazole should be carefully monitored to avoid promoting bacterial resistance.
Available forms
Phthalylsulfathiazole is typically given orally in tablet form to target intestinal infections directly. Due to the phthalic acid substitution on the aniline nitrogen, it remains unabsorbed in the bloodstream, focusing its action within the gut.
Common side effects include nausea, stomach upset, and skin rash. Rare but serious adverse effects may involve vitamin B deficiency, agranulocytosis, or aplastic anemia.
Mechanism of action
Phthalylsulfathiazole acts by competitive antagonism with para-aminobenzoic acid, inhibiting the dihydropteroate synthetase enzyme crucial for dihydrofolic acid synthesis. This inhibition disrupts purine and pyrimidine synthesis, impairing bacterial growth and reproduction. Once in the large intestine, phthalylsulfathiazole hydrolyzes to release sulfathiazole, the active antimicrobial component.