Polyenes

What are Polyenes?

Antifungal agents are also called antimycotic agents.

Polyene antifungals bind to ergosterol, the main sterol in the fungal cell membrane, and cause depolarization of the membrane. This increases the membrane permeability and leads to cell death.

They are not absorbed when given orally, so are used to treat fungal infections of the gastrointestinal tract, such as oral thrush. For treatment of systemic fungal infections they need to be administered intravenously.

Polyenes are a class of organic compounds well known for their potent antifungal properties. They are effective due to their ability to target and disrupt fungal cell membranes by binding to ergosterol and forming pores.

Polyene Antifungal Drugs
These drugs interact with sterols in cell membranes (ergosterol in fungal cells; cholesterol in human cells) to form channels through the membrane, causing the cells to become leaky (Fig. 76-2). The polyene antifungal agents include nystatin, amphotericin B, and pimaricin.

Polyene antifungal drugs are known to exhibit antifungal activity by binding to ergosterol and inhibiting its cellular functions with (amphotericin B) or without (natamycin) permeabilizing the fungal membrane.

It was therefore suggested that these polyene antibiotics be classified into two groups: group 1 (pimaricin, pentamycin, and filipin) and group 2 (amphotericin B and nystatin).

Macrolides are a class of drugs used to manage and treat various bacterial infections. Azithromycin, clarithromycin, and erythromycin are commonly used to treat infections like pneumonia, sinusitis, pharyngitis, and tonsillitis. They are also used in uncomplicated skin infections and otitis media in pediatric patients.

Typically derived from the fermentation products of Streptomyces bacteria, polyene antifungals bind to ergosterol in the fungal cell membrane, allowing K+ and Na+ ions to leak out. Resistance (Ahmad et al, 2019).