Drugs: The Structure Of The Fungus

To start we must talk a bit about the structure of the fungus to understand how these drugs act, like bacteria fungi have a cell wall which is a target for these drugs but why are not the same antimicrobials used? As the composition of the wall is different, that of the bacteria is formed by peptidoglucan and that of the fungi by chitin and gluacano, so the metabolic routes that synthesize these compounds easily become targets.Image created by the author

There is also a very important compound because it closely resembles human cholesterol and it is ergosterol that is also part of the pharmacological targets.Others act by altering the function of the cell membrane by altering the stability of the cell, and finally we have the drugs that act by inhibiting the synthesis of nucleic acids.Image created by the authorAmphotericin BThis is a drug that modifies the function of the membrane, this antifungal I remember it very well since it was discovered in Venezuela specifically isolated from a bacterium that was found in the Orinoco river, Streptomyces nodosus.De Lanulos -, Public domain, LinkIts mechanism of action derives from its amphoteric property that is given by the presence of a carboxyl group and an amino group and in addition to having a hydrophilic and a lipophilic portion, and when in contact with sensitive fungi it binds to the sterols present in the cellular membrane, in this case ergosterol (unlike the human cell that it has is cholesterol, this gives specificity to fungi) changing the characteristics of the membrane causing the content to escape, functioning more or less like soap.

This drug comes in different pharmacological presentations, all to be used intravenously, the different forms exist due to the lower presence of adverse effects.Lipids allow higher doses but they are very expensive and at least in Venezuela they are not available.Therapeutic usesIt is usually used in various systemic or profound mycoses, such as meningitis caused by fungi of the genus Coccidioides or by Cryptococco, systemic infections by Candida, eye infections, esophagitis, mucormycosis, histoplasmosis, blastomycosis, invasive aspergillosis, sporotrichosis, etc. In conclusion it is a drug widely used to treat mycoses.Side effectsThe main effect of which we must be very careful is the renal involvement, it is a nephrotoxic drug so the patient treated with amphotericin B must be under medical supervision.

Other side effects are: anemia, fever, chills, hypotension and alterations in respiratory frequency and amplitude.separador.png5-Flurocytosine5-Flurocytosine is a drug that interferes with the synthesis of nucleic acids of some fungi, these fungi have several enzymes that metabolize 5-Flurocytosine giving a final product that is toxic to him, humans lack these enzymes, which is why this drug It would not affect our cells.De Fvasconcellos -, Public domain, LinkTherapeutic usesCurrently it is a drug that is only used (combined) to treat diseases caused by the fungus Criptococco, although some authors recommend its use in chromoblastomycosis.Side effectsEffects such as neutropenia (decrease in white blood cells) and thrombocytopenia (decrease in platelets) and gastrointestinal involvement have been described.