Folate Synthesis inhibitors

Question 1

Sulfamethoxazole (SMX)

Answer 1

• Mech: competitive inhibitor of dihydropteroate synthetase

Question 2

Sulfadiazine and silver sulfadizazine

Answer 2

• Mech: inhibits dihydropteroate synthetase
• Oral mono therapy for UTIs and burns
  Silver Sulf Use: topical, prevention and treatment of infections related to skin burns or superficial wounds
• Adverse effects: sulfa-hypersensitivity and photosensitivity
• hemolytic anemia, nephrotoxic, and kernicterus in infants

Question 3

Trimethoprim (TMP)

Answer 3

• Mech: inhibits dihydrofolate reductase, 20-50x more potent than sulfonamides
• C. difficile growth and bone marrow suppression

Question 4

Cotrimoxazole

Answer 4

• TMP-SMX combo
• combo more effective than either of its individual components
• Use: treatment of P. jiroveci, recurrent UTIs, HFLU