In the natural microflora of humans and animals, pathogenic fungi are not present. Fungi are eukaryotes that lack chlorophyll and are incapable of photosynthesis. Most fungi are saprophytes of the environment (heterotrophs) and need to be fed with ready-made organic substances. The body of the fungus is represented by the mycelium - a network of thin branching tubular filaments called hyphae. Mushrooms multiply by spores. Getting into the tissues of a susceptible host during accidental inoculation, in its favorable nutrient substrates, fungi can cause various diseases of the skin, mucous membranes, and internal organs. Fungal diseases are called mycoses (from the Greek. Mykes - fungus).
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 can affect, in addition to the skin, muscles, bones, internal organs and nervoussystem. Actinomycosis is a serious disease caused by actinomycetes radiant fungi, blastomycosis is a deep skin mycosis, the causative agent is a pathogenic dimorphic fungus. Other diseases also belong to deep (visceral) mycoses. Superficial mycoses affect the stratum corneum, scalp, nail plates and mucous membranes.
The most common keratomycosis, which affects only 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 leg, interdigital folds, brushes;
- trichomycosis (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 with dermatophytes (less often mold or yeast).
For diseases caused by various types of pathogenic or opportunistic fungi, antifungal drugs are used. Depending on the localization of pathogenic fungi, antifungal drugs are classified 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 different chemical groups: undecylenic acid ciclopirox, flucytosine, potassium iodide, etc.
Onychomycosis
The cause of onychomycosis is infection of the nail plate. Most of the infection occurs in public baths, saunas, swimming pools. Scales, which contain spores and mycelium of fungi, falling off in patients with onychomycosis, fall on the floor, benches, trellises, paths, carpets and bedding. In conditions of high humidity, mushrooms can not only persist for a long time (years), but also multiply, which makes them an intense source of infection. A person who moves barefoot on the floor or touches household items with such scales may well become infected, becausethey stick to his skin and are fixed. The infection develops after the penetration of the fungus into 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, flaky rashes in the interdigital area. Such diseases are distinguished by a long and persistent course.
The likelihood of susceptibility to infection increases with age, especially in the elderly over 65, due to the presence of such chronic diseases as vegetative-vascular pathology, diabetes mellitus, peripheral circulatory disorders, osteoarthropathy of the feet, etc. changes in the nail plates.
Treatment of onychomycosis is carried out strictly according to a certain scheme for a long period of time - from 2 to 4 months. In therapy, antimycotics are used, which have a fungistatic and fungicidal effect and affect various stages of the vital activity and metabolism of pathogens. There are three main mechanisms of the antimycotic action of antifungal drugs, which 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, by inhibiting the synthesis of nucleic acids (griseofulvin);
- inhibition of the processes of transmembrane exchange through the cell membrane of fungi (ciclopirox).
Drugs of choice
Griseofulvin(Griseofulvinum) tab. 125 mg is an antibiotic produced by the mold Penicillium nigricans (griseofulvum), was isolated in 1939 and is a spiro derivative of benzofuran in structure. The drug has fungistatic properties against all types of fungi - trichophytes and epidermophytes. The mechanism of fungistatic action is based on the drug's ability to inhibit cell division of filamentous fungi in metaphase, causing characteristic morphological changes (twisting, increased branching and curvature of hyphae), disrupting the structure of the mitotic spindle and cell wall synthesis. To a small extent, the drug inhibits the synthesis and polymerization of nucleic acids. The drug has no antibacterial activity.
To create a sufficient concentration of the drug in the skin requires long-term treatment - 2-3 months min. Only on new, regrown nails will the first symptoms of the effectiveness of treatment be noticeable.
Important! Side effects when taking the drug include: dyspeptic disorders, dizziness, sometimes insomnia, allergic reactions, leukopenia. Griseofulvin is contraindicated in suppression of hematopoiesis, liver and kidney failure, as well as in infants and pregnant women. You should not prescribe the drug to transport drivers, persons engaged in high-altitude work or requiring increased attention, quick mental and motor reactions. Patients should be warned about the development of possible cross-sensitivity to penicillin and about the increased effect of alcohol.
Ketoconazole(Ketoconazole) - an active broad-spectrum drug from the imidazole group with fungicidal and fungistatic activity; effective when taken orally with systemic and superficial mycoses, dermatomycosis and candidiasis. It is prescribed by a doctor for the treatment and prevention of fungal infections of the skin, hair, nails, genitals caused by pathogens sensitive to the drug.
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 skin rash, headache, dizziness, gynecomastia, impotence. With the simultaneous use of the drug with other drugs (fentanyl, tamsulosin, carbomazepine, salmeterol, etc. ), the concentration of the latter may increase with an increase in side effects.
Contraindicated in severe liver, kidney, pregnancy, breastfeeding and hypersensitivity to the drug.
Ketoconazole is available in the table. 200 mg suppository. 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 - vial150 ml - the drug has a wide spectrum of action, selectively and specifically inhibit the enzyme that catalyzes the synthesis of fungal sterols. Scope: various infections caused by dermatophytes and / or yeast and mold fungi, such as candidiasis of the mucous membranes (including the vagina), skin mycoses, onychomycosis, epidermomycosis, fungal lesions of the eyes (keratitis), peritoneum and other localizations. Taking Itraconazole capsules immediately after meals increases its bioavailability; the maximum concentration in blood plasma is reached within 3-4 hours. after ingestion. The drug is well distributed in tissues that are susceptible to fungal infections.
Important! When using the drug, side effects from the digestive system may occur: dyspepsia (nausea, vomiting, diarrhea, constipation, loss of appetite), abdominal pain, impaired taste; headache, dizziness, allergic reactions, alopecia, from the hematopoietic organs (infrequently) - leukopenia, thrombocytopenia. The use is contraindicated in case of hypersensitivity to itraconazole and any of the components of the drug, children under 3 years of age, pregnancy and lactation.
For optimal absorption of the drug, it is necessary to take the capsules without chewing, immediately after a meal, swallow whole. One course of pulse therapy for onychomycosis consists of a daily intake of 2 caps. the drug twice a day for one week. For the treatment of fungal infections of the nail plates of the hands, two courses are recommended. For the treatment of fungal infections of the nail plates of the feet, three courses are recommended. The interval between courses, during which 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 referred to as allylamines and is prescribed for systemic and external use. The mechanism of action of Terbinafine is associated with inhibition of the initial stage of the biosynthesis of ergosterol (the main 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 pathogenic for humans. With local treatment, 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 sebaceous glands, hair follicles and nail plates in concentrations that provide a fungicidal effect. 1 tab. once daily terbinafine results in higher cure rates and better outcomes for each efficacy criterion (including mycological cure) than intermittent intraconazole therapy.
Naftifin(Naftifine) cream 1% - 15, 30 g; 1% solution 10, 20, 30 ml, is a derivative of allylamines. The mechanism of action is associated with inhibition of the activity of the enzyme squalene-2, 3-epoxidase, inhibition of the biosynthesis of ergosterols, which leads to a violation of the synthesis of the cell wall. Naftifine has a broad spectrum of action, acting fungicidal against dermatophytes (such as Trichophyton, Epidermophyton, Microsporum), mold (Aspergillus spp. ), Yeast-like fungi (Candida spp. , Pityrosporum) and other fungi, for example (Sphenor scorotrichosis). . . The drug has an anti-inflammatory effect, reduces itching. When applied externally, it penetrates well into the skin, creating stable antifungal concentrations in its various layers.
The duration of treatment with Naftifin varies from 2 weeks to 6 months. When using the drug, dryness and redness of the skin, a burning sensation may occur, all these side effects are reversible and do not require cancellation.
Amorolfine(Amorolfine) nail polish 5% - 2. 5 and 5 ml, - a preparation for external use, has a wide spectrum of action, providing fungistatic and fungicidal action due to damage to the cytoplasmic membrane of the fungus by disrupting sterol biosynthesis, due to inhibition of enzymes 14–gamma demethylase and 7 gamma isomerase. The drug is active against both the most common and rare pathogens of fungal infections of the nails of dermatophytes: Trichophyton spp. , Microsporum spp. , Epidermophyton spp . ;molds: Alternaria spp. , Scopulariopsis spp. , Hendersonula sppi . ;fungi from the Dematiaceae family: Cladopsorium spp. , Fonsecaea spp. , Wangiella spp . ;dimorphic fungi Coccidioides spp. , Histoplasma spp. , Sporothrix spp.
When applied to nails, the drug penetrates into the nail plate and further into the nail bed, almost completely within the first 24 hours. Effective concentration remains in the affected nail plate for 7-10 days. after the first application. Systemic absorption is negligible. It is applied externally. The drug is applied to damaged finger or toenails 1-2 times a week. The duration of treatment is determined individually and depends on the indications for use. Side effects are rare and appear in the form of itching, burning at the site of application. 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 signs 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 glycerol - are used to treat and prevent fungal skin diseases caused by fungi (dermatophytes) sensitive to the drug.
The preparations are applied to a clean, dry surface of the affected skin 2 times a day (morning and evening). The duration of the course of treatment is 4-6 weeks and depends on the nature, effectiveness and course of the disease. After the disappearance of the clinical signs of the disease, 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 drug that inhibits the capture of precursors for the synthesis of macromolecules in the cell membrane. Applied externally for the treatment and prevention of fungal infections of the skin, mucous membranes, nails, fungal vaginitis and vulvovaginitis.
The drug is applied 1-2 times a day to the affected nail, the duration of use depends on the severity of the lesion, but should not exceed 6 months.
Treatment of onychomycosis should take place under the strict supervision of a dermatologist. As a rule, a rational etiotropic complex therapy is used. A decrease or disappearance of clinical symptoms is usually observed a few days after taking an antimycotic. However, in order to avoid relapses of the disease, the course of treatment should be carried out completely. Against the background of clinical cure, anti-relapse therapy is often carried out, aimed at preventing re-infection.