According to the Centers for Disease Control and Prevention, there has recently been a significant increase in the number of fungal infections. This increase is mainly affecting people who have impaired immune systems. If you have a weakened immune system, then you have an increased risk of being affected by fungi that are usually considered harmless and also by new forms of fungi. However, physicians do have anti-fungal remedies at their disposal.
Fungi have a substance called ergosterol in their cell membrane. Ergosterol is very similar to the cholesterol that is in your cells. Amphotericin B works by attaching to the ergosterol. It then changes the permeability of the fungal cell, or in other words, what the cell will allow to enter and exit. It creates pores all throughout the membrane of the fungal cell. Substances that the cell requires for life will leak out, and thus, the fungus will eventually die.
According to Don Sheppard, M.D., Assistant Professor in the Department of Medicine, Microbiology and Immunology at McGill University, there are two types of azole antifungal remedies, the imidazoles and the triazoles. The imidazole group includes the medications called ketoconizole, clotrimazole and miconazole. The triazole group includes fluconazole, itraconazole, posaconazole and voriconazole. The azoles may differ in how long they stay in your bloodstream, but they all work the same. They all interfere with an enzyme that the fungus needs to make ergosterol, which important to all fungi because they need a certain amount of it to make cell membranes.Without enough ergosterol to make cell membranes, bacteria will die.
The fungus takes flucytosine into its cells and changes it to a substance which interferes with its ability to make DNA and RNA. The fungus must be able to make DNA and RNA to survive. The cells in your body do not change flucytosine, so your DNA and RNA is not affected. (Your blood level of flucytosine must be carefully monitored, however, because high levels of this drug can have a negative affect on your liver and bone marrow.)
Griseofulvin attaches to the keratin protein of your new skin cells, forming a protective coating against any fungal infection. It does not attack the fungus on your existing, infected skin cells. Your infection is only eliminated when the old, infected skin cells die off, that is, when your old skin has been replaced by new skin. This is why it must be used for weeks and even months to give time for this process to occur.
Dr. Sheppard writes in “Basic & Clinical Pharmacology,” that the echinocandins are the newest antifungal remedy. They include medications called anidulafungin, micafungin and caspofungin. Echinocandins differ from each other by the length of time they stay in your bloodstream. They all kill fungi by interfering with its ability to make a substance called beta(1-3)-glucan. Fungi need this substance to make their cell wall; without it, they cannot survive.
Like the azoles, terbinafine interferes with an enzyme that the fungus needs to make ergosterol. It is not the same enzyme that is targeted by the azoles, however. By terbinafine interfering with this enzyme, called squalene epoxidase, a substance called squalene accumulates inside the fungal cell and destroys the fungus.
Nystatin kills fungi in the same manner that amphotericin B does. It attaches to ergosterol, changes the permeability of the fungal cell and creates pores. Substances that the fungal cell needs for survival leak out and this destroys the fungus.
About this Author
Based in North Carolina, Ruth Coleman has written articles and manuals for 25 years. Her writing has appeared in community newspapers, places of employment and comprises work done in medical college, of which she is a recent graduate. Ruth Coleman holds a Bachelor of Science in biology from Salem College, and is the recipient of numerous academic awards.