What are the oral antifungal drugs?

There are many types of medicines, most of which are specially formulated according to the characteristics of various diseases and have a strong therapeutic effect on the diseases. Among various diseases, fungal diseases are the most difficult to treat and require long-term use of antifungal drugs. Antifungal drugs are best taken orally and have the least side effects. Let’s take a look at what oral antifungal drugs are available. I hope everyone can understand.

1. Triazoles

Azole antifungals, including imidazoles and triazoles. Imidazoles include: ketoconazole, clotrimazole, miconazole, econazole and sertaconazole. Currently, most of them are topical medications for superficial fungal infections or candidal infections of the skin and mucous membranes. Triazoles include fluconazole, itraconazole, voriconazole, and the research-stage saconazole, pasoconazole, ravuconazole, SCH39304 (SM8668), and SDZ89-485, all of which can be used to treat deep fungal infections. The main target enzyme of azole drugs is 14-demethylase (14-DM). The 3rd or 4th nitrogen atom on the imidazole ring and triazole ring is embedded in the iron atom of the enzyme's cytochrome P450 protein, inhibiting the catalytic activity of 14-DM, preventing lanosterol from being converted into 14-demethyllanosterol, and further preventing the synthesis of ergosterol, which in turn blocks the synthesis of fungal cell membranes and causes fungal cell rupture and death.

2. Polyenes

Polyene antifungal drugs include: amphotericin B (AmB), amphotericin B lipid complex (ABLC), amphotericin sulfate cholesteryl ester (ABCD), liposomal amphotericin B (L-AmB) and nystatin. This type of drug interacts with the sterols on the phospholipid bilayer of the fungal cell membrane, causing water-soluble pores to form in the cell membrane, changing the permeability of the cell membrane, and ultimately leading to the loss of important cellular contents and causing the death of the fungus. Amphotericin B can also produce a bactericidal effect by stimulating macrophages to regulate autoimmune function. Nystatin liposomes (NYS) can bind to ergosterol on the fungal cell membrane, reduce the stability of the cell membrane, and are active against a variety of fungi.

3. Echinocandins

These compounds are non-competitive inhibitors of 1,3-β-D-glucan synthase, which inhibit its biological activity without affecting the biosynthesis of nucleic acids and mannan. 1,3-β-D-glucan is an important substance for maintaining the integrity of fungal cell walls, but Cryptococcus lacks this substance. 1,3-β-D-glucan deficiency leads to increased fungal cell wall permeability, cell lysis, and fungal death. 1,3-β-D-glucan does not exist in human cells.