Sweatman antifungals from chapter 48 Flashcards
T/F with advances in medicine, fungal infections are decreasing
False
T/F Amphotericin B is completely ineffective if given orally
False, oral Amphotericin B can treat GI fungus
T/F Amphotericin B is highly bound to serum proteins
True
Half life of Amphotericin B?
15 days
Where is Amphotericin B distributed? What tissues?
All tissues except CNS
Whats the benefit of Liposomal Amphotericin B?
Lipid transporter of Amphotericin allows for higher doses and less toxicity without losing effects
Amphotericin B’s mechanism of action please?
Binds to ergosterol on fungus membranes and causes pore formation
How can a fungus become resistant to Amphotericin B?
If ergosterol binding is impaired, of course!
How can this happen?
Reducing or modifying ergosterol on fungal membranes
Antifungal agent with broadest spectrum of action?
Amphotericin B
For treatment of systemic fungal disease, how is amphotericin B administered?
Slow IV infusion
Most common toxic reaction for Amphotericin?
Renal damage
Name of the fungal enzyme that metabolizes flucytosine leading to the drug’s selective toxicity in fungi
Cytosine permease
Mechanism of action of azoles please?
Inhibit fungal CYP450’s thus reducing ergosterol production
T/F Azoles are usually highly toxic
False, they are relatively nontoxic. Most common adverse reaction is a minor upset stomach
Why are azoles so ready to have adverse reactions?
Because they act on CYP450s. They inhibit fungal cyp450, but we have them too! Lots of adverse interactions
Intraconazole has reduced bioavailability when taken in conduction with what drug?
Rifamycins
Treating HBS (histoplasma, blastomyces, sporothrix). what azole to use?
Itraconazole
Widest theraputic index of the azoles?
Fluconazole
Fluconazole has a low or high penetration of CSF?
HIgh, it gets in that CSF like a sum bitch
Azole with most inhibition of CYP3A4?
Vericonazole
Vericonazole has what common side effect?
Vision disturbances
Treatment of choice (TOC) for invasive aspergillosis?
Vericonazole
This azole is particularly high distributing in tissues
Posaconazole
Broadest spectrum anti fungal of the azole family
Posaconazole (has activity against most sp. of Candida and Aspergillus)
Caspofungin, micafungin, anidulafungin all belong to a group of anti-fungals called?
Echinocandins
Mechanism of action of echinocandins please?
Inhibit beta-glucan in fungal cell walls
What treats systemic dermatophytosis?
Griseofulvin
Mechanism of action of Terbinafine please?
Inhibits squalene epoxidase
