1.3 Antifungal pharm

Question 1

What is the MOA for Amphoteracin B?

Answer 1

Binds to the ergosterol sites and creates pores that leak K+ which disrupts the internal environment of the fungal cell

Question 2

What fungus is intrinsically resistant to Amphoteracin B?

Answer 2

Pseudoallescheria boydii

Question 3

What characteristic do fungus resistant to Amphoteracin B have?

Answer 3

Low ergosterol content

Question 4

What are the three azole antifungals?

Answer 4

Voriconazole, Fluconazole, and Itraconazole

Question 5

What is the MOA of the azoles and how can it impact other drugs?

Answer 5

Inhibit the CYP450 enzyme to prevent ergosterol synthesis but can can affect the impact of other drugs that are metabolized by the enzyme

Question 6

Which drug(s) lead to a Q-T prolongation?

Answer 6

The azoles (Voriconazole, Fluconazole, and Itraconazole)

Question 7

What is the first line treatment for Pneumocystic jiroveci and what is its MOA?

Answer 7

Trimethoprim-sulfamethoxazole - Inhibits the biosynthesis of tetrahydrofolate

Question 8

What enzymes do Trimethoprim and sulfamethoxazole inhibit?

Answer 8

Dyhydrofolate reductase and Dihydropteroate synthase

Question 9

What is the second line defense for Pneumocystic jiroveci and what is its MOA?

Answer 9

Atovaquone - Looks like coenzyme Q (ubiquinone) and inhibits the electron transport chain

Question 10

What is a mechanism of drug resistance for azoles?

Answer 10

Energy-dependent drug efflux pumps

Question 11

What is the primary treatment for aspergillum?

Answer 11

Voriconazole or Amphoteracin B

Question 12

How do you treat the following diseases?

Answer 12

• Blastomycosis - Itraconazole or AmphoB (Fluconazole second)
• Histoplasmosis - Itraconazole
• Paracoccidioides - Itraconazole (AmphoB second)
• Coccidioides - Itraconazole or Fluconazole (AmphoB second)