This document discusses sulfonamides, which are the first antimicrobial agents effective against pyogenic (pus-forming) bacteria. It provides a brief history of sulfonamides, noting their discovery in 1935 and first successful use in treating infections in 1937. The document classifies and describes the mechanism of action of sulfonamides as structural analogues of para-aminobenzoic acid (PABA) that compete to create non-functional folic acid analogues, ceasing bacterial growth. Key points about the pharmacokinetics, uses, contraindications and adverse effects of sulfonamides are summarized.

1. SULFONAMIDES
PRESENTED BY,
MITESH LUNGASE
GUIDED BY,
MRS. DEEPIKA PRAJAPATI
ACADEMIC YEAR 2023-24
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2. INTRODUCTION
1. Sulfonamides are the first antimicrobial agents effective against the pyogenic
bacteria (pus forming bacteria).
2. They are p-amino benzene sulfonamide derivatives forms the active moiety
sulfanilamide.
3. Sulfonamides are primarily bacteriostatic against most of Gram +ve and
Gram –ve bacteria.
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3. history
 In 1935, sci Domagk discovered the first sulfonamide dye prontosil red (chemically
sulfonamido chrysoidine) which was effective against streptococcal infection in the mice .
 In 1937, this dye also cured infant infected by staphylococcal septicaemia (100 % fatal that
time).
 Sulfanilamide was the active moiety in prontosil red which was effective against
streptococcal infection in mice.
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4. CLASSIFICATION OF SULFONAMIDES
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5. MECHANISM OF ACTION
– Folic Acid is very essential for the growth of bacteria as it is crucial for
nucleic acid synthesis.
– Many bacteria synthesize their own folic acid from PABA.
– Sulfonamides are structural analogues of PABA ,enters the sequence in
place of PABA.
– Sulfonamides compete for enzyme dihydropteroic acid synthase to
create a non-functional analogue of folic acid.
– This is of no use to bacteria hence.
– GROWTH CEASES (BACTERIOSTATIC ACTION)
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7. PHARMACOKINETIC
– Route of administration: Oral (well absorbed from upper GIT).
– Disribution: CSF, Placenta(widely disributed) 20-90 percent drugs
protein bound.
– Metabolism: Liver (acetylation).
– Excretion: Kidney (tubular secretion &glumerular filtration).
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8. uses
1. Sulfadiazine –meningitis
2. sulfamethoxazole-it is used in combination with
trimethoprime combination as cotrimoxazole
3. Sulfacetamide sodium –ophthalmic preparation
4. Silver sulfadiazine & mefenide –in Burn therapy
5. Sufasalazine (prodrug) –Ulcerative colitis(5 –ASA)
6. Sulfamethopyrazine-in combination with pyrimethamine
for malaria ,pneumocystic jiroveci,taxoplasmosis gondii
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9. CONTRAINDICATION
Pregnancy.
Premature infant.
Renal impairment.
Dehydration.
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10. ADVERSE EFFECTS
1. Crystalluria (major)
2. Hypersensitivity- Steven-Jhonson syndrome
3. Epigastric pain
4. Haemolytic Anamia – in G-6PD deficient patient
5. Hepatitis (in 0.1 % patients)
6. Kernicterus- It is the precipitation of bilirubin inside the brain of newborn
due to displacement of bilirubin from plasma protein binding site
7. Nausia ,vomiting
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