Pathogenic fungi are not present in the natural microflora of humans and animals. Fungi are eukaryotes that lack chlorophyll and are not capable of photosynthesis. Most fungi are saprophytes from the environment (heterotrophs) and should be fed with ready-made organic substances. The body of the fungus is represented by mycelium - a network of thin branched tubular threads called hyphae. Fungi multiply by spores. Entering the tissues of a sensitive host during accidental inoculation, in their 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 causes 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 severe and can affect, in addition to the skin. , muscles, bones, internal organs and nervous system. Actinomycosis is a serious disease caused by actinomycetes of the fungus, blastomycosis is a deep skin mycosis, the cause 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 legs, interdigital folds, brushes;
- tricomycosis (from the Greek trichos - hair) - damage to the scalp, vellus hair on the body;
- trichophytosis (lichen), microsporia, favus (scab);
- onychomycosis (from the Greek onychos - nail) - damage to the nail plates on the hands or feet by dermatophytes (rarely mold or yeast).
Antifungal drugs are used for diseases caused by various types of pathogenic or opportunistic fungi. Depending on the localization of pathogenic fungi, antifungal drugs are classified as drugs for the treatment of:
- systemic mycoses;
- candidiasis;
- superficial mycoses.
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);
- derivatives of different chemical groups: undecylenic acid, cyclopirox, flucytosine, potassium iodide, etc.
Onychomycosis
Onychomycosis is caused by an infection of the nail plate. Most of the infection occurs in public baths, saunas, swimming pools. The scales, which contain spores and mycelium of the fungus, fall off in patients with onychomycosis, fall to the floor, benches, bars, paths, carpets and bedding. In conditions of high humidity mushrooms can not only last a long time (years), but also multiply, which makes them an intense source of infection. A person who walks on the floor barefoot or touches household items with such a scale can become infected because they stick to his skin and become fixed. The infection develops after the fungus penetrates the nail structures. In the future they begin to activate, multiply and form tunnels, pass through. When affected, the nails thicken, crumble, turn yellow and break. Sometimes the process also affects the skin, which is accompanied by an itchy, scaly rash on the interdigital area. Such diseases are characterized by a long and persistent course.
The probability of susceptibility to infection increases with age, especially in the elderly over the age of 65, due to the presence of such chronic diseases as vegetative-vascular pathology, diabetes mellitus, peripheral circulation disorders, osteoarthropathy of the feet, etc. Changes in nail plates.
Treatment of onychomycosis is carried out strictly according to a certain scheme for a longer period of time - from 2 to 4 months. Antimycotics are used in therapy, which have a fungistatic and fungicidal effect and affect different phases of vital activity and pathogen metabolism. There are three main mechanisms of antifungal action of antifungal drugs that show their activity as a result:
- violations of the structure and function of the cell wall of fungi (imidazoles, triazoles);
- violation of eukaryotic cell mitosis, by inhibiting nucleic acid synthesis (griseofulvin);
- inhibition of the process of transmembrane exchange through the cell membrane of fungi (cyclopirox).
Medications of choice
GriseofulvinCard (Griseofulvinum). 125 mg is an antibiotic produced from the mold Penicillium nigricans (griseofulvum), 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 ability of the drug to inhibit the cellular division of filamentous fungi in metaphase, causing characteristic morphological changes (twisting, increased branching and curvature of the hyphae), disrupting the structure of mitotic spindle and cell wall synthesis. The drug slightly inhibits the synthesis and polymerization of nucleic acids. The drug has no antibacterial action.
To create a sufficient concentration of the drug in the skin requires long-term treatment - 2-3 months min. Only on new, adult nails will the first symptoms of treatment effectiveness be noticeable.
Bitan! Side effects while taking the medicine include: dyspeptic disorders, dizziness, sometimes insomnia, allergic reactions, leukopenia. Griseofulvin is contraindicated in the suppression of hematopoiesis, liver and kidney failure, as well as in newborns and pregnant women. You should not prescribe the medicine to transport vehicles, people engaged in high-altitude jobs or who need increased attention, quick mental and motor reactions. Patients should be warned of the development of possible cross-sensitivity to penicillin and to the enhanced effect of alcohol.
Ketoconazole(Ketoconazole) - a broad-spectrum active drug from the group of imidazoles with fungicidal and fungistatic action; 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 drug-sensitive pathogens.
When given orally, the drug is well absorbed, dissolved and absorbed in an acidic environment.
Bitan! The drug is well tolerated by patients, but 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 concomitant use of the drug with other drugs (fentanyl, tamsulosin, carbamazepine, salmeterol, etc. ), the concentration of the latter may increase with increasing 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% fat, 15 mg; cream 20 mg / g - 15 g. It is used in the form of shampoo. The duration of treatment is determined individually.
Itraconazole(Itraconazole) capsules. 100 mg; solution 10 mg / ml - bottle150 ml - the drug has a broad 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 mucosal candidiasis (including vagina), skin mycoses, onychomycosis, epidermomycosis, fungal eye lesions (keratitis), peritoneum and other localizations. Taking Itraconazole capsules immediately after a meal increases its bioavailability; the maximum concentration in blood plasma is reached in 3-4 hours. after swallowing. The drug is well distributed in tissues susceptible to fungal infections.
Bitan! When using the drug, side effects of the digestive system may occur: dyspepsia (nausea, vomiting, diarrhea, constipation, loss of appetite), abdominal pain, impaired taste; headache, dizziness, allergic reactions, alopecia, from hematopoietic organs (rare) - leukopenia, thrombocytopenia. Use is contraindicated in case of hypersensitivity to itraconazole and any of the components of the drug, children under 3 years, pregnancy and lactation.
For optimal absorption of the drug, the capsules should be taken without chewing, swallowed whole immediately after a meal. One course of pulse therapy for onychomycosis consists of a daily intake of 2 drops. medication twice daily for one week. Two courses are recommended for the treatment of fungal infections of the nail plates of the hands. For the treatment of fungal infections of the nail plates of the feet, three sequences are recommended. The interval between courses, during which you do not have to take the drug, is 3 weeks.
Terbinafine(Terbinafine) - produced in the form of: tab. 250 mg; 1% fat 15, 0 g; 1% cream - a tube of 10, 15, 30 g; 1% spray, 20 ml. The drug is called allylamine and is prescribed for systemic and external use. The mechanism of action of Terbinafine is associated with inhibition of the initial phase of ergosterol (major cellular sterol of the fungal membrane) biosynthesis by inhibition of the specific enzyme squalene-2, 3-epoxidase on the fungal membrane. The drug is effective against many fungi pathogenic to humans. With topical treatment, Terbinafine is more effective than azole, an imidazole derivative, but comparable to itraconazole, and when administered orally, it is more effective than griseofulvin and itraconazole. Terbinafine is characterized by lipoidophilicity, rapidly diffuses into the stratum corneum of the epidermis, dermis, subcutaneous tissue, accumulates in 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; A 1% solution of 10, 20, 30 ml is an allylamine derivative. The mechanism of action is associated with inhibition of the activity of the enzyme squalene-2, 3-epoxidase, inhibition of ergosterol biosynthesis, which leads to a violation of cell wall synthesis. Naftifine has a broad spectrum of action, acting fungicidal against dermatophytes (such as Trichophyton, Epidermophyton, Microsporum), molds (Aspergillus spp. ), Yeast-like fungi (Candida spp. , Pityrosporum) and other fungi, for example (Sphenor scorotrichosis). . . The drug has anti-inflammatory, reduces itching. When applied externally, it penetrates well into the skin, creating stable antifungal concentrations in different layers.
The duration of Naftifine treatment varies from 2 weeks to 6 months. When the drug is used, dryness and redness of the skin may occur, a burning sensation, all these side effects are reversible and do not require cancellation.
Amorolfine(Amorolfine) nail polish 5% - 2, 5 and 5 ml, - preparation for external use, has a wide range 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 7gamma isomerase. The drug is active against both the most common and rare causes of fungal infections of nail dermatophytes: Trichophyton spp. , Microsporum spp. , Epidermophyton spp. molds: Alternaria spp. , Scopulariopsis spp. , Hendersonula sppi. fungi of the family Dematiaceae: 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, almost completely in 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 the damaged toe or toenail 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 newborns.
Undecylenic acidand its salts - antifungal drugs for external use, which act fungistatically and fungicidal against dermatophytes, in combination 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 of 30 g tube, ointment of 25 g in bottles);
- Undecylenic acid + copper undecylenate + HCV glycerol - used to treat and prevent fungal skin diseases caused by drug-sensitive fungi (dermatophytes).
The preparations are applied to a clean and 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.
Bitan! Contraindication to the use of the drug is hypersensitivity to undecylenic acid and its derivatives.
Cyclopirox(Ciclopirox) nail polish 8%, sp. 3 g, is a broad-spectrum antifungal drug that inhibits the capture of precursors for the synthesis of macromolecules in the cell membrane. It is 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 on the affected nail, the duration of use depends on the severity of the lesion, but should not be longer than 6 months.
Treatment of onychomycosis should be carried out under the strict supervision of a dermatologist. As a rule, rational etiotropic complex therapy is used. Reduction or disappearance of clinical symptoms is usually observed a few days after taking antifungals. However, in order to avoid recurrence of the disease, the course of treatment should be carried out completely. In the background of clinical cure, anti-relapse therapy aimed at preventing re-infection is often performed.