Sketchy Pharm: Amphotericin, Flucytosine Flashcards
Recall that fungal membranes are composed of _______________ instead of cholesterol.
ergosterol
How does amphotericin work?
It binds ergosterol and forms pores in the fungal cell membrane.
(Think of the holes in the amphibian tank that are letting the water out.)
How can fungi develop resistance to amphotericin?
They can down-regulate ergosterol in the membrane. Without ergosterol, amphotericin is not able to penetrate the cell membrane.
How is amphotericin administered?
Intravenously (like the ivy on the frog’s cage)
Typically, amphotericin is only used for _______________.
systemic, life-threatening infections (represented by the anatomical body system model next to the frog’s cage)
How have drug developers packaged amphotericin so that it’s less toxic?
They make liposomal fat formulations that slow the delivery of the drug into the system and limit binding to human cholesterol.
(Think of the large frog chin representing a swollen liposome.)
What are the infusion-related toxicities?
- Hypotension (teacher fainting)
- Headache (teacher grabbing his head)
- Fever (frog sweating next to bunsen burner)
Note: the teacher is doing this in response to the frog suddenly jumping on him, which represents the infusion reaction.
For CNS infections, amphotericin is administered ___________________.
intrathecally (like the frog’s tongue directly on the model’s brain)
________________ can occur at the injection site.
Thrombophlebitis (like the blue veins swollen on the frogs)
Intrathecal administration can cause ____________.
seizures (like the shaking seizure lines around the model)
_________________ occurs in almost all patients receiving amphotericin.
Irreversible renal damage (often type 1 acidosis)
Think of the chemist holding the yellow fluid in the tube shaped like a 1.
What electrolyte abnormalities are seen in amphotericin renal toxicity?
Hypokalemia from the renal tubular acidosis (think of the chemist slipping on the banana peel) and hypomagnesemia (like the magnets falling into the sink
To counteract the renal effects of amphotericin, ____________ is often administered during or before amphotericin.
saline (like the emergency saline shower)
How does amphotericin cause anemia?
From kidney damage leading to decreased EPO production (like the broken kidney-shaped jar that’s spilling blood)
Amphotericin is often used with ______________ to treat Cryptococcal meningitis.
flucytosine (like the flute player across the hall)