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 environmental saprophytes (heterotrophs) and need to be fed with prepared 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. By entering the tissues of a susceptible host during accidental inoculation, on their favorable nutritive 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 microscopic parasitic fungi of the genus: Arthroderma, Aspergillus, Amanita, Microsporum, Penicillium, Candida, Saccharomyces, Trichophyton, Epidermophyton, etc. Systemic mycoses of the internal organs are very difficult and can affect, in addition to the skin, muscles, bones, internal organs and nervous system. Actinomycosis is a serious disease caused by radiant actinomycete fungi, blastomycosis is a deep cutaneous 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, affecting only the stratum corneum; Dermatomycoses affect the smooth skin, the epidermis and its appendages: hair, nails.
Depending on the type of pathogenic fungus and the location of the pathological process, there are:
- epidermophytosis - mycosis of the skin of the inguinal folds, lower leg, interdigital folds, brushes;
- trichomycosis (from the Greek trichos - hair): damage to the scalp, hair on the body;
- trichophytosis (ringworm), microsporia, favus (scabies);
- 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 location of the 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, amphoglycamine, natamycin, nystatin);
- non-polyene antibiotics (griseofulvin);
synthetic drugs:
- Imidazole derivatives (bifonazole, isoconazole, ketoconazole, clotrimazole, miconazole, oxiconazole, omoconazole, sertaconazole);
- triazole derivatives (itraconazole, fluconazole, thermoconazole, tioconazole);
- allylamine derivatives (terbinafine, naphthifine);
- Morpholine derivatives (Amorolfine);
- derived from different chemical groups: cyclopirox undecylenic acid, 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 fungal spores and mycelium, which are shed in patients with onychomycosis, fall to the ground, benches, trellises, paths, carpets and bedding. In conditions of high humidity, fungi 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 can become infected, because they stick to his skin and become 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 scaly and itchy rashes in the interdigital area. Such diseases are distinguished by a long and persistent course.
The probability of susceptibility to infection increases with age, especially in the elderly 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 period of time - 2-4 months. In therapy, antifungal agents 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 antifungal 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 eukaryotic cell mitosis, by inhibiting nucleic acid synthesis (griseofulvin);
- inhibition of transmembrane exchange processes through the fungal cell membrane (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 fungistatic mechanism of action is based on the drug's ability to inhibit cell division of filamentous fungi in metaphase, causing characteristic morphological changes (torsion, increased branching and curvature of hyphae), altering the structure of the mitotic spindle and the cell wall synthesis. To a small extent, the drug inhibits nucleic acid synthesis and polymerization. The drug has no antibacterial activity.
To create a sufficient concentration of the drug on the skin, long-term treatment is required - 2-3 months minimum. Only on new and regenerated nails will the first symptoms of the effectiveness of the treatment be noticed.
Important! Side effects when taking the drug 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 infants and pregnant women. You should not prescribe the drug to transportation drivers, people who perform work at high altitudes or require increased attention, mental and rapid motor reactions. Patients should be warned about the development of possible cross-sensitivity to penicillin and about the increased effect of alcohol.
Ketoconazole(Ketoconazole) - a broad-spectrum active 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 physician for the treatment and prevention of fungal infections of the skin, hair, nails, and genitals caused by drug-sensitive pathogens.
When administered orally, the drug is well absorbed, dissolves, and absorbs in an acidic environment.
Important! 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 hives and rash, headache, dizziness, gynecomastia, impotence. With simultaneous use of the drug with other drugs (fentanyl, tamsulosin, carbamazepine, salmeterol, etc. ), the concentration of the latter may increase with increased side effects.
Contraindicated in severe cases of liver, kidney, pregnancy, lactation 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(Itraconazole) plugs. 100 mg; 10 mg / ml solution - 150 ml vial - 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), cutaneous mycoses, onychomycosis, epidermomycosis, fungal lesions of the eyes (keratitis), peritoneum and other locations. Taking itraconazole capsules immediately after meals increases its bioavailability; the maximum concentration in blood plasma is reached in 3-4 hours. after ingestion. The drug distributes well to tissues that are susceptible to fungal infections.
Important! When using the drug, digestive system side effects may occur: dyspepsia (nausea, vomiting, diarrhea, constipation, loss of appetite), abdominal pain, taste disturbance; headache, dizziness, allergic reactions, alopecia, of 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. A pulse therapy course for onychomycosis consists of a daily intake of 2 capsules. the drug twice a day for a 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 it is not necessary to take the drug, is 3 weeks.
Terbinafine(Terbinafine) - produced in the form: tab. 250 mg; 1% ointment 15. 0 g; 1% cream - tube of 10, 15, 30 g; Spray 1%, 20 ml. The drug is known as 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 the biosynthesis of ergosterol (the main cellular sterol of the fungal membrane) by inhibiting the specific enzyme squalene-2, 3-epoxidase in the fungal membrane. The drug is effective against many fungal pathogens for humans. With local treatment, terbinafine is more effective than the imidazole-derived azo drugs, but comparable to itraconazole, and when administered orally, it is more effective than griseofulvin and itraconazole. Terbinafine is characterized by its lipophilicity, it diffuses rapidly in 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. Terbinafine once daily results in higher cure rates and better results for each efficacy criterion (including mycological cure) than intermittent intraconazole treatment.
Naftifin(Naphthyphin) 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, 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), mold (Aspergillus spp. ), Yeast fungi (Candida spp. , Pityrosporum) and other fungi, for example (Sphenor's Sccorotrichosis) . . . 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 Naftifin treatment ranges 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.
Amorolfina(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 interrupting sterol biosynthesis , due to the inhibition of the enzymes 14– gamma demethylase and 7 gamma isomerase. The drug is active against 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 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 on 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 nails of the damaged fingers or toes 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 application site. Not prescribed for young children and babies.
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 in 30 g tube, 25 g ointment in bottle);
- Undecylenic acid + copper undecylenate + HCV glycerol: used to treat and prevent 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 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.
Ciclopirox(Ciclopirox) 8% nail polish, fl. 3 g, is a broad spectrum antifungal drug that inhibits the capture of precursors for the synthesis of macromolecules in the cell membrane. Externally applied for the treatment and prevention of fungal infections of the skin, mucosa, 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 injury, but should not exceed 6 months.
Treatment of onychomycosis should be done under the strict supervision of a dermatologist. As a general rule, a rational etiotropic complex therapy is used. A decrease or disappearance of clinical symptoms is usually seen within a few days after taking an antifungal. However, in order to avoid relapses of the disease, the course of treatment must be carried out completely. In the context of clinical healing, relapse therapy is often carried out, aimed at preventing reinfection.