Antifungal Drugs (92) Flashcards
What are fungi?
A large and diverse group of microorganisms
-yeasts, models
What is the term referred to as fungal infections s
Mycoses
Superficial fungal infection
-integumentary
-mucus membranes
Systemic fungal infections
Can be life threatening
-prolonged therapy
-use of toxic drugs
-immunocompromised host
Candida albicans in immunocompromised patients
A common yeast that causes thrush or vaginal yeast infections
-naturally found on the body (bad for immunocompromised)
-may result in overgrowth and systemic infections
Dermatomycoses
Infections of the hair, nails or skin caused by fungus
-tinea or ringworm
Naturally occuring anti fungal drugs (2)
-polyenes
-echinocandins
Synthetic anti fungal drugs
-azoles
-pyrimidines
Two types of polyenes
Amphotericin B and nystatin
One type of azoles
Fluconazole
-importantly they end in ZOLE
Amphotericin B
Usually given for systemic infections
-slow IV injection
-lipid and non lipid preparations
Fluconazole
Systemic infections
-there are multiple administration routes
Nystatin
Oral infections
-suspension should be swished thoroughly in the mouth as long as possible before swallowing
PO/topical azoles would be used to target
Superficial infections
-vaginal candidiasis, tinea
-Fluconazole
Ergosterol is very similar to what chemical?
Cholesterol
Polyenes mechanism of action
Binds to sterols (Ergosterol in fungal cells) in cell membrane lining, makes holes in fungi cell membranes and causes cell death
Higher concentrations of polyenes are at risk of what?
Binding to cholesterol of human cells to cause toxicities
-taking this drug daily
Mechanisms of actions for Azoles
Inhibit sterol altering enzyme, leading to altered cell membrane, inhibits growth = death
Azoles inhibit sterol altering enzyme leads to
Less ergosterol in membranes
-CYP P450 enzymes
Adverse effects of amphotericin B
MANY :(((
-renal toxicity (K+ loss)
-impairs hepatic functions
What needs to be assessed before delivering amphotericin B
You need to assess the kidney and liver functions
Less important other adverse effects of amphotericin B
-fever, headache, malaise, hypotension, muscle and joint pain, chills, dysrythmias, nausea, vomiting, anorexia
How can one reduce the severity of infusion related reaction to amphotericin B (3)
PROPHYLACTIC drugs
-antipyretic
-antihistamines
-antiemetics
A test dose is given to assess reaction
Many azoles will inhibit…
Hepatic CYP enzymes
