Polyene antimycotic

Polyene antimycotic‏‎, also known as polyene antifungal, is a type of antimicrobial medication used to treat fungal infections. These drugs are derived from species of Streptomyces, a genus of bacteria that is known for its prolific production of antibiotics.

Mechanism of Action

Polyene antimycotics work by binding to ergosterol, a component of fungal cell membranes. This binding disrupts the integrity of the cell membrane, leading to increased permeability and eventual cell death. The specificity of polyenes for ergosterol helps to limit their toxicity to human cells, which contain cholesterol instead of ergosterol in their membranes.

Types of Polyene Antimycotics

There are several types of polyene antimycotics, including:

• Amphotericin B: This is the most commonly used polyene antimycotic. It is used to treat severe systemic fungal infections and is often a drug of last resort due to its potential for severe side effects.
• Nystatin: This is used primarily for the treatment of Candida infections of the skin, mouth, and vagina.
• Natamycin: This is used primarily for the treatment of fungal infections of the eye.

Side Effects

The use of polyene antimycotics can lead to several side effects, including kidney damage, anemia, and infusion reactions (for intravenous formulations). The risk of side effects can be mitigated through careful monitoring and dose adjustment.

Resistance

Resistance to polyene antimycotics is relatively rare, but can occur through changes in the fungal cell membrane that reduce the binding affinity of the drug for ergosterol.