The use of antifungal drugs is aimed at fighting infections caused by fungi or fungal infections, also known as "yeast infection" or "fungus”. The fungus may be incurred by the skin, mucous membranes, nails and hair (cutaneous mycoses or dermatomycosis and mucocutaneous fungal infection); borne of the subcutaneous tissues, muscles and fascia (subcutaneous mycoses); borne by the eyes, digestive tract, respiratory tract, urinary tract, nervous system, etc. (systemic or deep fungal infections). These may include ringworm fungus, the tinea versicolor, athlete's foot, aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, Maduromycosis and others.
There are three mechanisms by which antifungal medicines act:
- Acting on the synthesis of the cell wall of the fungus, leading to osmotic instability and making it vulnerable to the toxic agents (drugs and antibodies);
- Acting on the cell membrane by inhibiting the synthesis of ergosterol, a compound similar to cholesterol in humans, crucial for the osmotic stability and metabolic fungal cells, compromising the reproduction and the infectious activity of yeast cells;
- Act on the fungal metabolism;
The first group includes the echinocandins and poliossine; the second group includes the polyene, the azole, the allylamines, and the morpholines; while the third group consists of the anti-metabolites.
How should antifungals be taken?
Antifungals are available in the market in the form of creams that allow a topical use (especially in the case of cutaneous mycoses or dermatomycosis), as well as in the form of tablets, capsules or solutions for injections (used in the case of more severe skin infections or in the case of systemic or deep fungal infections). The antifungal agent should always be used under medical prescription and the patient is required to strictly follow the instructions of the doctor regarding the dosage and mode of application. Not doing so can reduce the absorption of the drug or render the treatment useless.
The duration of treatment varies greatly from case to case: some fungal infections, especially those most superficial, may require a few days of antifungal use, while others may require continuous treatment for several weeks.
Contraindications and warnings associated with the use of antifungal agents
In the case of topical applications for a few days, the antifungal drugs are very well tolerated by the human organism. However, the intake by mouth or intravenously, can cause different side effects that may occur in a more or less accentuated way depending the duration of therapy and tolerability of the subject to the drug used. In general, the adverse effects of antifungal drugs can be summarized as follows:
- Gastrointestinal disorders: nausea, vomiting, diarrhea, abdominal pain;
- Systemic disorders: fever, hypotension;
- Cardiac disorders: arrhythmia, thrombophlebitis;
- Musculoskeletal disorders: muscle and joint aches, muscle weakness;
- Haematological disorders: decrease of red blood cells and platelets;
- Renal disorders;
In cases of pregnancy and lactation, the use of topical antifungals should be discussed with a doctor on a case-by-case basis, adapted to each individual patient; instead, the use of oral and intravenous antifungals is usually not recommended in these cases.
