Metabolic Antagonist Agents

Question 1

Which are the metabolic antagonists?

Answer 1

• Sulfonamides
• Trimethoprim
• Isoniazid

Question 2

When are the metabolic antagonists effective?

Answer 2

When differences exist between metabolic pathways of host and pathogen

Question 3

What are the characteristics of Sulfonamides?

Answer 3

• Structural analogs of PABA
• Competitively binds enzyme that normally binds PABA in the folate synthesis pathway
• Human cells do not have this enzyme

Question 4

What are the characteristics of Trimethoprim?

Answer 4

• Acts on the enzyme that catalyzes a subsequent step in the folate synthesis pathway
• Structural analog of DHFA (product of the previous step)
• Trimethoprim and sulfonamides often given in conjunction to provide a synergistic effect
• This combination is a primary treatment for PCP in AIDS patients