Antifungals Flashcards
Many antifungals are moderate to strong inhibitors of this
CYP3A4
Amphotericin B, the -azoles, the -fungins, and Flucytosine (5-fluorocystine) treat these kind of fungi
Subcutaneous/systemic
Griseofulvin, Nystatin, Terbinafine and Naftifine treat this type of fungi
Cutaneous
2 enzymes involved in fungal ergosterol synthesis that are targets for antifungals
Squalene epoxidase
14-alpha-demethylase (a CYP450 molecule)
Amphotericin B, Azoles, Echinocandins and Flucytosine treat this type of mycoses
Systemic
Natural polyene antifungal produced by Streptomyces bacteria
Amphotericin B
Amphotericin B is a natural polyene antifungal produced by this
Streptomyces bacteria
Streptomyces bacteria produce this antifungal
Amphotericin B
Antifungal effective against wide range of fungi, including Candida albicans, Coccidioides immitis, and many strains of Aspergillus
Amphotericin B
Antifungal that binds to fungal membrane component ergosterol
Alters fungal cellular permeability, a pore former mechanism
Amphotericin B
MOA of Amphotericin B
Binds to fungal membrane component ergosterol
Alters fungal cellular permeability = a pore former
Amphotericin B binds to this fungal component
Membrane component ergosterol
Primarily administration route of Amphotericin B
IV
(inhalation and oral routes possible)
Does Amphotericin B penetrate the meninges?
No - poor penetration into most compartmented fluids (meningeal, humoral, etc.)
Biotransformation rate of Amphotericin B
Slow
Half life can vary considerably
Half life of Amphotericin B
Can vary considerably; 24 hours to 15 days (depending on the state of renal function, number of doses, tissue storage)
Common adverse effects of Amphotericin B are related to this
Infusion related
Headache, fever, chills, hypotension, nausea/vomiting and tachypnea
Infusion related adverse effects of Amphotericin B (headache, fever, chills, hypotension, nausea/comiting and tachypnea) can be managed by premedicating with these 3
Ibuprofen, Antihistamines, Steroids (hydrocortisone)
Pretreating Amphotericin B with ibuprofen, antihistamines, and steroids is a method of managing this
Infusion related adverse effects (headache, fever, chills, hypotension, nausea/vomiting, tachypnea)
Severe chills as a result of Amphotericin B can be treated with this
Meperidine
Meperidine can treat this adverse effect of Amphotericin B
Chills, if severe
infusion-related
Principle adverse effect associated with long-term treatment of Amphotericin B
Nephrotoxicity
Nephrotoxicity is the principle adverse effect associated with long-term treatment of this antifungal
Amphotericin B
Antifungal with a black box that states it should be used in serious invasive fungal infections only and at safe dosages
Amphotericin B
Formulation of Amphotericin B that reduces nephrotoxicity but prolongs infusion reaction
Liposomal formulations
Liposomal formulations of this drug reduce nephrotoxicity but prolong infusion reaction
Amphotericin B
Amphotericin B liposomal formulations reduce this
Reduce nephrotoxicity
but prolong infusion reaction
Amphotericin B liposomal formulations reduce nephrotoxicity but prolong this
Infusion reaction
Antifungal indicated for a wide range of fungal infections, commonly for Candida infections, Cryptococcosis, Sporotrichosis and other dangerous systemic fungal infections
Azoles
Antifungals that inhibits fungal lanosterol 14-alpha-demethylase (CYP51A1) thereby inhibiting fungal ergosterol synthesis
Increases fungal permeability by same mechanism
Azoles
MOA of Azoles
Inhibits fungal lanosterol 14-alpha-demethylase (CYP51A1) thereby inhibiting fungal ergosterol synthesis (fungistatic)
Increases fungal permeability by same mechanism
Azoles inhibit this enzyme
lanosterol 14-alpha-demethylase (CYP51A1)
(involved in fungal ergosterol synthesis)
Azoles inhibit fungal lanosterol 14-alpha-demethylase, aka this enzyme
CYP51A1
Azoles inhibit CYP51A1, aka this enzyme
lanosterol 14-alpha-demethylase
Azoles inhibit fungal lanosterol 14-alpha-demethylase (CYP51A1), thereby inhibiting synthesis of this
Ergosterol
Spectrum of Azoles
Broad spectrum antifungal activity; resistance is an emerging problem
Absorption of Azoles require this
Acidic environment (except fluconazole)
Azoles require acid environment for oral absorption, with this exception
Fluconazole