Sulfonamides

Question 1

Sulfonamides

Mechanism

Answer 1

Bacteriostatic
Suppress bacterial growth by triggering a Mechanism that inhibits Folic Acid synthesis.
Forces the bacteria to synthesize their own folic Acid

Question 2

Sulfonamides

Spectrum

Answer 2

Broad spectrum
G+ve : S. Pyogens, S. Pneumoniae
G -ve : H influenzae, E. Coli, Proteus Mirabilis

Chlamydia
Nicardia
Actinomyces
Bacillus anthacis

Question 3

Sulfonamides

Indications

Answer 3

UTIs (by E. Coli)
Chronic cystitis
Upper respiratory tract inf
Nicardiosis
Trachoma
Inclusion conjectuvitis
Dermatitis herpetiformis

Sulfadiazine : pyrimethamine to treat toxoplasmosis
Sulfamethoxazole: trimethoprim (bactrim) to treat pneumonia, shigellosis, serratia inf. UTIs , resp inf. Gonococcal urethritis
Sulfisoxazole: erythromycin otitis media, UTIs
Phenazopyridine for relief of pain burning and urgency

Question 4

Sulfonamides side effects

Answer 4

Blood dyscrasias (Hemolytic anemia in G6PD deficient )
Aplastic anemia, thrombocytopenia, Agranulocytosis, eosinophila

Hypersensitivity

Crystalluria & hematuria (UT obstruction)

Hepatitis (life threatening) rare

AIDS patients have increased frequency of cutaneous hypersensitivity to sulfamethoxazole

Question 5

Sulfonamides

Interactions

Answer 5

Potentiate effect of:
Phenytoin
Oral Anti coagulant
Sulfonylureas