In the natural microflora of humans and animals, pathogenic fungi are not present. Fungi are eukaryotes devoid of chlorophyll and incapable of photosynthesis. Most fungi are environmental saprophytes (heterotrophs) and must 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 multiply by spores. Getting into the tissues of a susceptible host during accidental inoculation, into its favorable nutrient substrates, the fungi can cause various diseases of the skin, mucous membranes and internal organs. Fungal diseases are called yeast infections (from the Greek. Mykes - fungus).
The agents responsible for mycoses are parasitic microscopic fungi of the genus: Arthroderma, Aspergillus, Amanita, Microsporum, Penicillium, Candida, Saccharomyces, Trichophyton, Epidermophyton, etc. Systemic yeast infections of internal organs are very difficult and can affect, in addition to the skin, muscles, bones, internal organs and the nervous system. Actinomycosis is a serious disease caused by radiating actinomycete fungi, blastomycosis is a deep skin mycosis, the causative agent is pathogenic dimorphic fungus. Other diseases also belong to deep (visceral) mycoses. Superficial yeast infection affects the stratum corneum, scalp, nail plaques and mucous membranes.
The most common keratomycosis, which affects only the stratum corneum; dermatomycosis affects smooth skin, the epidermis and its integuments: hair, nails.
Depending on the type of pathogenic fungus and the localization of the pathological process, there are:
- epidermophytosis - mycosis of the skin of the inguinal folds, lower leg, interdigital folds, brushes;
- tricomycosis (from the Greek trichos - hair) - damage to the scalp, fluffy hair on the body;
- trichophytosis (ringworm), microsporia, favus (scabies);
- onychomycosis (from the Greek onychos - fingernail) - damage to 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 location of pathogenic fungi, antifungal drugs are classified into drugs to be treated:
- systemic mycoses;
- candidiasis;
- superficial yeast infection.
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);
- morpholine derivatives (amorolfine);
- derived from different chemical groups: undecylenic acid ciclopirox, flucytosine, potassium iodide, etc.
Onychomycosis
Onychomycosis is caused by an infection of the nail plaque. Most of the infection occurs in public baths, saunas, swimming pools. Scales, which contain fungal spores and mycelium, fall in patients with onychomycosis, fall to the floor, benches, trellises, walkways, rugs and bedding. Under conditions of high humidity, the fungi can not only persist for a long time (years), but also multiply, making them an intense source of infection. A person who walks barefoot on the floor or touches household objects with such scales may very well be infected, as they stick to their 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 touched, the nails thicken, crumble, turn yellow and break. Sometimes the process also affects the skin, which is accompanied by itching and scaly rashes in the interdigital area. These diseases are distinguished by a long and persistent course.
The likelihood of susceptibility to infection increases with age, especially in people over 65 years of age, due to the presence of chronic diseases such as vegetative-vascular pathology, diabetes mellitus, peripheral circulatory disorders, osteoarthropathy of the feet, etc. nail plates.
Treatment of onychomycosis is carried out strictly according to a certain scheme for a long time - from 2 to 4 months. In therapy, antimycotics are used, which have a fungistatic and fungicidal effect and affect various stages of vital activity and metabolism of pathogens. There are three main mechanisms of antimycotic action of antifungal drugs, which manifest their activity accordingly:
- violations of the structure and function of the cell wall of fungi (imidazoles, triazoles);
- violation of mitosis of eukaryotic cells, inhibiting the synthesis of nucleic acids (griseofulvin);
- inhibition of transmembrane exchange processes across the cell membrane of fungi (ciclopirox).
Medication of choice
Griseofulvintab (Griseofulvinum). 125 mg is an antibiotic produced by the mold Penicillium nigricans (griseofulvum), was isolated in 1939 and is a spiro derivative of benzofuran in its structure. The drug has fungistatic properties against all types of fungi - trichophytes and epidermophytes. The fungistatic mechanism of action is based on the ability of the drug to inhibit the cell division of filamentous fungi in metaphase, causing characteristic morphological changes (torsion, increased branching and curvature of hyphae), disrupting the structure of the mitotic spindleand 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, long-term treatment is required - 2-3 months min. Only on new and regrown nails will the first symptoms of the effectiveness of the treatment be noticeable.
Important! Side effects when taking the drug include: dyspeptic disturbances, dizziness, sometimes insomnia, allergic reactions, leukopenia. Griseofulvin is contraindicated in the suppression of hematopoiesis, hepatic and renal failure, as well as in infants and pregnant women. You should not prescribe the drug to transport drivers, people performing work at high altitudes or requiring increased attention, rapid mental and motor reactions. Patients should be cautioned about the development of possible cross-sensitivity to penicillin and the increased effect of alcohol.
Ketoconazole(Ketoconazole) - an active broad-spectrum drug from the group of imidazoles with fungicidal and fungistatic activity; effective when taken orally with systemic and superficial mycosis, dermatomycosis and candidiasis. It is prescribed by a doctor for the treatment and prevention of fungal infections of the skin, hair, nails and 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 allergic reactions in the form of urticaria and rash, headache, dizziness, gynecomastia, helplessness. 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 cases of hepatic insufficiency, renal function, pregnancy, lactation and hypersensitivity to the drug.
Ketoconazole is available in the table. Suppository 200 mg. 400 mg; ointment 2%, 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 inhibits 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 yeast infections, onychomycosis, epidermomycosis, fungal lesions of the eyes (keratitis), peritoneum andother locations. 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 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, altered taste; headache, dizziness, allergic reactions, alopecia, hematopoietic organs (rarely) - 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 them, immediately after a meal, swallow them whole. A course of pulse therapy for onychomycosis consists of taking 2 capsules daily. the drug twice a day for a week. For the treatment of fungal infections of the nail plates of the hands, two cures are recommended. For the treatment of fungal infections of the nail plates of the feet, three cures 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; cream 1% - tube of 10, 15, 30 g; Aerosol 1%, 20 ml. The drug is called allylamines and is prescribed for systemic and external use. The mechanism of action of terbinafine is associated with the inhibition of the initial stage of biosynthesis of ergosterol (the main cell sterol of the fungal membrane) by inhibiting the specific enzyme squalene-2, 3-epoxidase on the membranefungal. The drug is effective against many fungi pathogenic to humans. With topical treatment, terbinafine is more effective than azole drugs, which are derived from imidazole, but comparable to itraconazole, and when given orally, it is more effective than griseofulvin and itraconazole. Terbinafine is characterized by lipoidophilia, rapidly diffuses into the stratum corneum of the epidermis, dermis, subcutaneous tissue, accumulates in sebaceous glands, hair follicles and nail plaques at concentrations that provide an effectivefungicide. 1 tab. once daily terbinafine results in higher cure rates and better results for each endpoint (including mycologic cure) than intermittent intraconazole therapy.
Naftifin(Naftifine) cream 1% - 15, 30 g; A 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 action, acting as a fungicide against dermatophytes (such as Trichophyton, Epidermophyton, Microsporum), molds (Aspergillus spp. ), Yeast-like fungi (Candida spp. , Pityrosporum) andother 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 of 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 thebiosynthesis of sterols, due to inhibition of the enzymes 14-gamma demethylase and 7 gamma isomerase. The drug is active against the most common and rare pathogens of fungal nail infections 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 the nails, the drug penetrates the nail plate and further into the nail bed, almost completely 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 applied externally. The drug is applied to damaged fingers or nails 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 as 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 tube 30 g, ointment 25 g in vials);
- 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 treatment is 4-6 weeks and depends on the nature, effectiveness and course of the disease. After the disappearance of clinical signs of the disease, they continue to be used once a day. For preventive purposes - 2 times a week.
Important! The 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 which inhibits the uptake 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, rational etiotropic complex therapy is used. A decrease or disappearance of clinical symptoms is usually observed a few days after taking an antimycotic drug. However, in order to avoid relapses of the disease, treatment should be carried out completely. In the context of clinical recovery, anti-relapse therapy is often implemented, aimed at preventing reinfection.