Intro To Antifungal Agents Flashcards
Few among millions of fungal species fulfil four basic conditions needed to infect humans, what are they?
High temp tolerance
Ability to invade human host
Lysis and absorption of human tissue
Resistance to the human immune system
How do antifungal medicines work?
By killing the fungal cells via fungicidal
Preventing fungal cells from growing and reproducing (Fungistatic)
Many antifungals are toxic so how can they be maintained for safety?
Superficial infections - topical preparations
Systemic therapy that is supervised
What are the two groups of drugs to treat fungal infections?
Antifungal antibiotics - Naturally occurring eg polyenes and echinocandins
Synthetic antifungal drugs - Azoles and pyrimidine analogues
Look at sites of action of common antifungal drugs image
What do echinocandins do?
They disrupt the formation of fungal cell wall
What is fungal cell wall composed of
1,6 B-d Glucans
Chitin
Mannans
Cell wall proteins
What are echinocandins
They are synthetically modified lipopeptides
Originally derived from fermentation broths of various fungi
What to echinocandins do?
Inhibit synthesis of 1,3 beta glucan leading to cell wall stress and lysis
What are sites of action for antiviral drugs
Non retrovirals
-inhibit viral DNA Polymerass
-Inhibits viral escape from infected cells
Difficult to find selective drugs as viruses use metabolic parts of host cell however there are some viral specific enzymes
Non retroviral and retroviral agents
Majority of current drugs only effective against replicating viruses - Prevention better than cure
what do inhibitors of viral DNA polymerase do?
E.g aciclovir
Prevent viral replication
What do viral neuraminidase do?
Enzymes that cleave sialic acid groups from glycoproteins
Found in surface of flu virus and enables virus to be released from host cell
Inhibitors of neuraminidase that prevent viral escape from infected cells are?
Eg oseltamivir and zanamivir
