Phthalylsulfathiazole (also known as sulfathalidine) belongs to the group of drugs called
sulfonamides. The drug is a
broad-spectrum antimicrobial that can treat different types of infections including intestinal. The mechanism of action depends on competitive antagonism with
para-aminobenzoic acid
4-Aminobenzoic acid (also known as ''para''-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the ''para'' position) is an organic compound with the formula H2NC6H4CO2H. PABA ...
and
inhibition of dihydropteroate synthetase activity, which in turn leads to impaired synthesis of
dihydrofolic acid
Dihydrofolic acid (conjugate base dihydrofolate) (DHF) is a folic acid ( vitamin B9) derivative which is converted to tetrahydrofolic acid by dihydrofolate reductase. Since tetrahydrofolate is needed to make both purines and pyrimidines, which ar ...
and as a result its active metabolite necessary for the synthesis of
purine
Purine is a heterocyclic aromatic organic compound that consists of two rings ( pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines ...
and
pyrimidine.
The drug is indicated in the treatment of
dysentery
Dysentery (UK pronunciation: , US: ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications ...
,
colitis
Colitis is swelling or inflammation of the large intestine ( colon). Colitis may be acute and self-limited or long-term. It broadly fits into the category of digestive diseases.
In a medical context, the label ''colitis'' (without qualification ...
,
gastroenteritis and intestinal surgery. It is not absorbed into the blood stream from the gut due to extra n⁴ substitute. Adverse effects may include allergic reactions,
vitamin B
B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. Though these vitamins share similar names (B1, B2, B3, etc.), they are chemically distinct compounds that often coex ...
insufficiency,
agranulocytosis and
aplastic anemia.
2-Thiazolyl compounds
Sulfonamide antibiotics
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