NBME 21 Amphotericin B (NBME Answers)

Retired NBME 21 Answers

nbme21/Block 1/Question#38 (reveal difficulty score)
A 47-year-old woman with aplastic anemia is ...
Amphotericin B 🔍 / 📺 / 🌳 / 📖
tags: pharm micro

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submitted by ∗et-tu-bromocriptine(140)

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Rule of thumb/shortcut

Nonserious fungal infections: treat with _conazole
Serious fungal infections (eg, immunocompromised patients with disseminated infection): treat with amphotericin B

Additional info

The main classes of antifungal medications for usmle include:
Polyenes (eg, amphotericin B, nystatin) - Bind to ergosterol molecules in fungal cell membranes, creating pores and causing cell lysis
Triazoles (eg, _conazole) - Prevent the synthesis of ergosterol, a component of fungal cell membranes
Echinocandins (eg, capsofungin, micafungin) - Inhibit the synthesis of glucan, a polysaccharide component of fungal cell walls
Pyrimidines (eg, Flucytosine) - Converted to 5-fluoruracil, which then inhibits fungal RNA and protein synthesis

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jcmed Cell Membrane = Amphotericin & Nystatin Cell WALL = Capsofungin To not mix them up I say to myself "IT's the FUNGIN CELL WALL" +3

Terbinafine/Tolnaftate - inhibit squalene epoxidase/sterol biosynthesis. Squalene builds interfere with fungal membrane function and cell wall synthesis.

+4/- h0odtime(54)

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submitted by ∗hungrybox(1277)

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My impression of Amphotericin B is that it's the BIG GUNS. It straight up attacks the sterols in the fungi plasma membrane.

Meanwhile lil bitch drugs like -azoles just inhibit sterol synthesis. (-terbinafine X lanosterol, -azoles X ergosterol)

Fungins X cell wall synthesis, flucytosine X nucleic acid synthesis.

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et-tu-bromocriptine Rule of thumb/shortcut: Nonserious fungal infections: treat with _conazole Serious fungal infection (eg, immunocompromised patients with disseminated infection): treat with amphotericin B Additional info The main classes of antifungal medications for usmle include: Polyenes (eg, amphotericin B, nystatin) - Bind to ergosterol molecules in fungal cell membranes, creating pores and causing cell lysis Triazoles (eg, _conazole) - Prevent the synthesis of ergosterol, a component of fungal cell membranes Echinocandins (eg, capsofungin, micafungin) - Inhibit the synthesis of glucan, a polysaccharide component of fungal cell walls Pyrimidines (eg, Flucytosine) - Converted to 5-fluoruracil, which then inhibits fungal RNA and protein synthesis +2

et-tu-bromocriptine Ripppp the formatting, but hopefully the idea gets across +

et-tu-bromocriptine Fixed it, see comment! +

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