Antifungal drugs Flashcards
Amphotericin B: MOA
binds ergosterol -> opens pores -> leakage of cellular contents and fungicidal death
-less selective tox because it also binds to cholesterol
Amphotericin B: PK props
IV or topically + bladder irrigation and Intraventricularly-intracisternally-intralumbarly for fungal meningitis
- rapidly sequestered in tissues then slowly released
- little CNS penetration
- slowly excreted by the kidney, major route biliary tract
Amphotericin B: adverse drug rxns
- nephrotox
- infusion-related: chills, fever, vom, rigor, hypotension with IV use (take aceptaminophen-dihenhydramine or admin with hydrocortisone; meperidine can dec duration of rigors)
- anemia
- Liposomal preps may reduce renal and infusion toxicities (serves as amphotericin reservoir reducing non-specific binding to human cell membranes)
Amphotericin B: role of pharacotherapy
drug of choice for life-threatening systemic fungal infections
- reliable against most
- used as initial induction therapy then replaced by one of the newer, less toxic azoles for maintenance
Nystatin: MOA
similar mech to Amphotericin B but TOX LIMITS SYSTEMIC USE
Nystatin: PK props
no oral, use topical
Nysatin: adverse drug rxns
mild and transient GI upset if swallowed
Nystatin: pharmacotherapy
candida infection of skin, mucous memb and GI tract
Echinocandins: MOA
disrupts cell wall (inhib synth of beta (1,3)-D-glucan)
-high levels of selective tox
Echinocandins: PK props
IV infusion
- dosage reduction required for hepatic insufficiency
- dosage inc if taking CYP450 inducers
Echinocandins: adverse drug rxns
- histimine-mediated sx (during infusion admin)
- fever, HV, HA, phlebitis
Echinocandins: pharmacotherapy
-invasive aspergillosis in pts with refractory or intolerant to other txs
