What is a polyene drug?

Polyene antibiotics are a class of antimicrobial compounds that bind to ergosterol, the main sterol in the fungal cell membrane, and cause depolarization. This increases membrane permeability and leads to leakage of intracellular cations causing cell death.

What is the difference between azole and triazole?

Triazoles have 3 atoms of nitrogen in the azole ring. Imidazoles have only two.

What are the azole medications?

Azole antifungal agents have added greatly to the therapeutic options for treatment of systemic fungal infections. The azoles that are available for systemic use can be classified into two groups: the triazoles (fluconazole, itraconazole, voriconazole, posaconazole, and isavuconazole) and the imidazoles (ketoconazole).

How do polyene antibiotics work?

Antifungal Drugs The polyene antibiotics are produced by Streptomyces species. Polyenes target the ergosterols the main component of fungal cell by destabilizing the plasma membrane and initiate cell lysis. Polyenes are also thought to cause oxidative damage. The polyene antifungal agents—amphotericin-B (33.1.

Is griseofulvin an polyene?

Abstract. There are 3 main classes of systemic antifungals: the polyene macrolides (e.g. amphotericin B), the azoles (e.g. the imidazoles ketoconazole and miconazole and the triazoles itraconazole and fluconazole) and the allylamines (e.g. terbinafine). Other systemic antifungals include griseofulvin and flucytosine.

What is the difference between triazoles and imidazoles?

The key difference between imidazole and triazole is that imidazole has non-adjacent nitrogen atoms in its chemical structure whereas triazole has adjacent nitrogen atoms in its chemical structure. Both these compounds are important medicines and have many other applications as well.

Is fluconazole a triazole?

Fluconazole is a new triazole antifungal agent with unique pharmacokinetic properties. It can be administered orally or parenterally and achieves rapid distribution by either route, and its absorption is not affected by the presence of food.

Which is the best azole?

List of Azole antifungals:

Drug Name Avg. Rating Reviews
Diflucan (Pro) Generic name: fluconazole 6.3 140 reviews
Sporanox (Pro) Generic name: itraconazole 8.3 18 reviews
Mycelex Troche Generic name: clotrimazole 4.7 7 reviews
Nizoral (Pro) Generic name: ketoconazole 6.4 4 reviews

What are polyenes and azoles used for?

Polyenes and azoles constitute 2 major drug classes in the antifungal armamentarium used to treat fungal infections of the eye such as fungal keratitis, endophthalmitis, conjunctivitis, and blepharitis.

What is the mechanism of action of polyenes?

Mechanism of action. Polyenes bind to ergosterol in the cell membrane of fungi and form aqueous pores that promote leakage of intracellular ions and disrupt active transport mechanisms dependent on membrane potential. They can be fungistatic or fungicidal.

What are polyenes made of?

Polyacetylenes or polyenes (acetylenic natural products) are composed of aliphatic hydrocarbons with carbon–carbon double and triple bonds [50]. Polyenes are typical of many plant families like Asteraceae, Apiaceae, Oleaceae, and Campanulaceae [40–42].

Why do fungi develop resistance to polyene antifungals?

Acquired resistance to polyene antifungals is rare but can occur in immunosuppressed people. Fungi develop mutations that enhance synthetic pathways for alternative sterols that replace ergosterol within the cell membrane and are unaffected by polyenes.