There are no pathogenic fungi in the natural microflora of humans and animals. Fungi are eukaryotes that lack chlorophyll and are incapable of photosynthesis. Most mushrooms are saprophytes of the environment (heterotrophs) and have to be fed with ready-to-use organic substances. The body of the fungus is represented by the mycelium - a network of thin, branched tubular filaments called hyphae. Fungi reproduce through spores. If fungi get into the tissue of a susceptible host during accidental inoculation, they can cause various diseases of the skin, mucous membranes and internal organs in their favorable nutrient substrates. Fungal diseases are called mycoses (from the Greek. Mykes - mushroom).
The causative agents of mycoses are parasitic microscopic fungi of the genus: Arthroderma, Aspergillus, Amanita, Microsporum, Penicillium, Candida, Saccharomyces, Trichophyton, Epidermophyton, etc. Systemic mycoses of internal organs are very difficult and, in addition to the skin, can also affect muscles, bones, internal organs and nervous system. Actinomycosis is a serious disease caused by actinomycetes radiation fungi, blastomycosis is deep skin mycosis, the causative agent is a pathogenic dimorphic fungus. Other diseases also belong to the deep (visceral) mycoses. Superficial mycoses affect the stratum corneum, the scalp, the nail plates and the mucous membranes.
The most common keratomycosis that only affects the stratum corneum; Dermatomycoses affect smooth skin, epidermis and its appendages: hair, nails.
Depending on the type of pathogenic fungus and the localization of the pathological process, there are:
- Epidermophytosis - mycoses of the skin of the inguinal folds, lower legs, interdigital folds, brushes;
- Trimycosis (from the Greek trichos - hair) - damage to the scalp, vellus hair on the body;
- Trichophytosis (ringworm), microsporia, favus (scab);
- Onychomycosis (from the Greek onychos - nail) - damage to the nail plates on the hands or feet by dermatophytes (less often mold or yeast).
Antifungal drugs are used for diseases caused by different types of pathogenic or opportunistic fungi. Depending on the localization of pathogenic fungi, antifungal drugs are divided into drugs for treatment:
- systemic mycoses;
- Candidiasis;
- superficial mycoses.
The chemical classification divides antifungal drugs into:
Antibiotics:
- Polyene antibiotics (amphotericin B, amphoglucamine, natamycin, nystatin);
- Non-polyene antibiotics (griseofulvin);
synthetic drugs:
- Imidazole derivatives (bifonazole, isoconazole, ketoconazole, clotrimazole, miconazole, oxyconazole, omoconazole, sertaconazole);
- Triazole derivatives (itraconazole, fluconazole, thermoconazole, thioconazole);
- Allylamine derivatives (terbinafine, naftifine);
- Derivatives of morpholine (amorolfine);
- Derivatives of various chemical groups: undecylenic acid ciclopirox, flucytosine, potassium iodide, etc.
Onychomycosis
Onychomycosis is caused by an infection of the nail plate. Most infections occur in public baths, saunas, and swimming pools. The scales, which contain spores and mycelium from fungus and which fall off in patients with onychomycosis, fall to the floor, benches, trellises, paths, carpets, and bedding. With high humidity, fungi can not only exist for a long time (years), but also multiply, which makes them an intense source of infection. A person who walks barefoot on the floor or touches household items with such scales can get infected because they stick to his skin and are fixed. The infection develops after the fungus penetrates the structures of the nail. In the future they begin to activate, multiply and form tunnels, passages. When affected, the nails thicken, crumble, turn yellow, and break. Sometimes the process also affects the skin, which is accompanied by itchy, scaly rashes in the interdigital area. Such diseases are characterized by a long and persistent course.
The likelihood of susceptibility to infection increases with age, especially in older people over 65 years, due to chronic diseases such as vegetative-vascular pathology, diabetes mellitus, peripheral circulatory disorders, osteoarthropathy of the feet, etc.
Treatment of onychomycosis is carried out strictly according to a certain scheme over a long period - from 2 to 4 months. In therapy, antimycotics are used, which have a fungistatic and fungicidal effect and influence various stages of vital activity and the metabolism of pathogens. There are three main mechanisms of the antifungal effect of antifungal drugs that manifest their activity as a result:
- violations of the structure and function of the cell wall of fungi (imidazoles, triazoles);
- violation of mitosis of eukaryotic cells due to inhibition of the synthesis of nucleic acids (griseofulvin);
- Inhibition of the processes of transmembrane exchange through the cell membrane of fungi (ciclopirox).
Medication of choice
Griseofulvin(Griseofulvinum) tab. 125 mg is an antibiotic produced by the mold Penicillium nigricans (griseofulvum), isolated in 1939, and its structure is a spiro derivative of benzofuran. The drug has fungistatic properties against all types of fungi - trichophytes and epidermophytes. The mechanism of fungistatic action is based on the ability of the drug to inhibit the cell division of filamentous fungi in the metaphase, which leads to characteristic morphological changes (twisting, increased branching and curvature of the hyphae) and disrupting the structure of the mitotic spindle and cell wall synthesis. The drug inhibits the synthesis and polymerization of nucleic acids to a small extent. The drug does not have an antibacterial effect.
In order to achieve a sufficient concentration of the drug in the skin, long-term treatment is required - 2-3 months min. Only with new, regrown nails, the first symptoms of the effectiveness of the treatment become noticeable.
Important! Side effects when taking the drug are: dyspeptic disorders, dizziness, sometimes insomnia, allergic reactions, leukopenia. Griseofulvin is contraindicated in the suppression of hematopoiesis, liver and kidney failure, as well as in infants and pregnant women. You should not prescribe the drug to convey quick mental and motor responses to drivers, people who work at high altitudes or who require increased attention. Patients should be cautioned about the development of a possible cross-sensitivity to penicillin and about the increased effects of alcohol.
Ketoconazole(Ketoconazole) - an active broad-spectrum drug from the imidazole group with a fungicidal and fungistatic effect; effective when taken orally for systemic and superficial mycoses, dermatomycosis and candidiasis. It is prescribed by a doctor to treat and prevent fungal infections of the skin, hair, nails, and genitals caused by pathogens sensitive to the medicine.
When administered orally, the drug is well absorbed, dissolved and absorbed in an acidic environment.
Important! The drug is well tolerated by patients, but it can cause dyspeptic symptoms (nausea, vomiting, diarrhea), very rarely there are allergic reactions in the form of urticaria and rash, headache, dizziness, gynecomastia, impotence. With the simultaneous use of the drug with other drugs (fentanyl, tamsulosin, carbamazepine, salmeterol, etc. ), the concentration of the latter may increase with an increase in side effects.
Contraindicated in severe liver, kidney, pregnancy, lactation and hypersensitivity to the drug.
Ketoconazole is available in the table. 200 mg suppositories. 400 mg; 2% ointment, 15 mg; Cream 20 mg / g - 15 g It is used in the form of shampoos. The duration of treatment is determined individually.
Itraconazole(Itraconazolum) caps. 100 mg; Solution 10 mg / ml - vial 150 ml - the drug has a wide spectrum of action, selectively and specifically inhibits the enzyme that catalyzes the synthesis of fungal sterols. Area of application: various infections caused by dermatophytes and / or yeasts and molds, such as candidiasis of the mucous membranes (including the vagina), skin mycoses, onychomycosis, epidermomycosis, fungal lesions of the eyes (keratitis), peritoneum and other locations. Taking itraconazole capsules immediately after meals increases bioavailability; the maximum concentration in the blood plasma is reached within 3-4 hours. after ingestion. The drug is well distributed in tissues prone to fungal infections.
Important! When using the drug, side effects of the digestive system may occur: dyspepsia (nausea, vomiting, diarrhea, constipation, loss of appetite), abdominal pain, taste disorders; Headache, dizziness, allergic reactions, alopecia, from the hematopoietic organs (rarely) - leukopenia, thrombocytopenia. Use is contraindicated in case of hypersensitivity to itraconazole and any component of the drug, in children under 3 years of age, pregnancy and lactation.
For optimal absorption of the drug, it is necessary to swallow the capsules whole immediately after a meal and swallow them whole. Pulse therapy for onychomycosis consists of a daily intake of 2 capsules. the drug twice a day for a week. Two courses are recommended for the treatment of fungal infections of the nail plates of the hands. Three courses are recommended for treating fungal infections of the nail plates of the feet. The interval between courses when you do not need to take the drug is 3 weeks.
Terbinafine(Terbinafine) - produced in the form: tab. 250 mg; 1% ointment 15. 0 g; 1% cream - 10, 15, 30 g tube; 1% spray, 20 ml. The drug is called allylamine and is prescribed for systemic and external use. The mechanism of action of terbinafine is linked to the inhibition of the initial stage of the biosynthesis of ergosterol (the most important cellular sterol of the fungal membrane) by inhibiting the specific enzyme squalene-2, 3-epoxidase on the fungal membrane. The drug is effective against many fungi that are pathogenic to humans. When treated locally, terbinafine is more effective than azole drugs, imidazole derivatives, but comparable to itraconazole, and when administered orally, it is more effective than griseofulvin and itraconazole. Terbinafine is characterized by lipoidophilicity, quickly diffuses into the stratum corneum of the epidermis, dermis, subcutaneous tissue, accumulates in the sebum glands, hair follicles and nail plates in concentrations that develop a fungicidal effect. 1 tab. once daily, terbinafine produces higher cure rates and better results for any criteria of effectiveness (including mycological cure) than intermittent intraconazole therapy.
Naftifin(Naftifine) cream 1% - 15, 30 g; 1% solution of 10, 20, 30 ml is a derivative of allylamines. The mechanism of action is associated with the inhibition of the activity of the enzyme squalene-2, 3-epoxidase, the inhibition of the biosynthesis of ergosterols, which leads to a violation of the synthesis of the cell wall. Naftifine has a broad spectrum of activity, has a fungicidal effect against dermatophytes (such as Trichophyton, Epidermophyton, Microsporum), mold (Aspergillus spp. ), Yeasts (Candida spp. , Pityrosporum) and other fungi, e. g. B. (Sphenor scorotrichosis). . . The drug has an anti-inflammatory effect, reduces itching. When used externally, it penetrates the skin well and creates stable antifungal concentrations in its various layers.
The duration of treatment with naftifine varies between 2 weeks and 6 months. When using the drug, dryness and reddening of the skin may experience a burning sensation, all these side effects are reversible and need not be canceled.
Amorolfin(Amorolfin) nail polish 5% - 2, 5 and 5 ml, - a preparation for external use, has a broad spectrum of activity and offers fungistatic and fungicidal effects due to damage to the cytoplasmic membrane of the fungus through disruption of sterol biosynthesis due to inhibition of the 14-gamma enzymes-Demethylase and 7-gamma isomerase. The drug is active against both the most common and the rarest causative agents of fungal infections of the nails of dermatophytes: Trichophyton spp. , Microsporum spp. , Epidermophyton spp. ; Molds: Alternaria spp. , Scopulariopsis spp. , Hendersonula sppi. ; Fungi of the Dematiaceae family: Cladopsorium spp. , Fonsecaea spp. , Wangiella spp. ; dimorphic fungi Coccidioides spp. , Histoplasma spp. , Sporothrix spp.
When applied to nails, the drug penetrates almost completely into the nail plate and further into the nail bed within the first 24 hours. The effective concentration remains in the affected nail plate for 7-10 days. after the first application. Systemic absorption is negligible. It is used externally. The drug is applied to damaged fingers or toenails 1-2 times a week. The duration of treatment is determined individually and depends on the application indications. Side effects are rare and occur in the form of itching and burning at the application site. Not prescribed for young children and infants.
Undecylenic acidand its salts - antifungal drugs for external use, which have a fungistatic and fungicidal effect against dermatophytes, when combined with zinc or copper salts - zinc undecylenate or copper undecylenate, the activity increases. Zinc, which is part of the drug, has an astringent effect, reduces the manifestations of skin irritation and promotes faster healing.
- Undecylenic acid + zinc undecylenate (TN, ointment 30 g tube, ointment 25 g in bottles);
- Undecylenic acid + copper undecylenate + HCV glycerin - are used to treat and prevent fungal diseases of the skin caused by sensitive fungi (dermatophytes).
The preparations are applied twice a day (morning and evening) to a clean, dry surface of the affected areas of the skin. The duration of treatment is 4-6 weeks and depends on the type, effectiveness and course of the disease. After the clinical signs of the disease have disappeared, they continue to be used once a day. For preventive purposes - 2 times a week.
Important! Contraindication to the use of the drug is hypersensitivity to undecylenic acid and its derivatives.
Cyclopirox(Ciclopirox) Nail Polish 8%, fl. 3 g, is a broad spectrum antifungal agent that inhibits the capture of precursors for the synthesis of macromolecules in the cell membrane. Topically used to treat and prevent fungal infections of the skin, mucous membranes, nails, fungal vaginitis and vulvovaginitis.
The drug is applied to the affected nail 1-2 times a day, the duration of use depends on the severity of the lesion, but should not exceed 6 months.
Treatment of onychomycosis should be under the strict supervision of a dermatologist. As a rule, rational etiotropic complex therapy is used. A decrease or disappearance in clinical symptoms is usually seen a few days after taking an antifungal drug. However, in order to avoid relapses of the disease, the course of treatment should be carried out in full. Against the background of clinical healing, anti-relapse therapy, aimed at preventing re-infection, is often carried out.