Description
release form
Tablets
packaging 16 pcs
Pharmacological action
Pharmacodynamics
Terbinafine is an allylamine that has a wide spectrum of action against fungi that cause diseases of the skin, hair and nails, including dermatophytes such as Trichophyton (e.g. T. rubrum, T. mentagrophytes, T. verrucosum, T. tonsurans, T. violaceum), Microsporum (e.g. M. canis), Epidermophyton floccosum, as well as yeasts of the genus Candida (e.g. C. albicans) and Malassezia (formerly Pityrosporum). In low concentrations, terbinafine has a fungicidal effect against dermatophytes, molds, and some dimorphic fungi. Activity against yeast fungi, depending on their type, can be fungicidal or fungistatic.
Terbinafine specifically inhibits the early stage of biosynthesis of sterols in the fungal cell. This leads to a deficiency of ergosterol and to intracellular accumulation of squalene, which causes the death of the fungal cell. The action of terbinafine is carried out by inhibiting the enzyme squalene epoxidase in the cell membrane of the fungus. This enzyme does not belong to the cytochrome P450 system.
When administered orally in the skin, hair and nails, concentrations of terbinafine are created to provide a fungicidal effect.
Pharmacokinetics
After oral administration, terbinafine is well absorbed (> 70%), the absolute bioavailability of terbinafine, due to the “first pass” effect, is about 50%. After a single oral administration of terbinafine in a dose of 250 mg, its maximum plasma concentration (Cmax) is reached after 1.5 hours and is 1.3 μg / ml. With constant administration of terbinafine, its Cmax increased by an average of 25%, compared with a single dose, the area under the concentration-time pharmacokinetic curve (AUC) increased by 2.3 times. Based on the increase in AUC, it is possible to calculate the effective half-life (30 hours).
Eating moderately affects the bioavailability of the drug (AUC increases by less than 20%), but dose adjustment while taking with food is not required.
Terbinafine binds significantly to plasma proteins (99%). It quickly penetrates the dermal layer of the skin and accumulates in the lipophilic stratum corneum of the epidermis. Terbinafine also penetrates the secretion of the sebaceous glands, which provides a high concentration of the substance in the hair follicles, hair and skin rich in sebaceous glands. Terbinafine also penetrates the nail plates in the first few weeks after the start of therapy.
Terbinafine is metabolized rapidly and, to a significant extent, with the participation of at least seven isoenzymes of cytochrome P450, with the major role being played by isoenzymes CYP2C9, CYP1A2, CYP3A4, CYP2C8 and CYP2C19. As a result of the biotransformation of terbinafine, metabolites are formed that do not have antifungal activity and are excreted mainly by the kidneys.
Repeated use of terbinafine, leading to an increase in its concentration in the blood serum, is accompanied by a three-phase excretion with a final half-life of about 16.5 days.
No changes in the equilibrium plasma concentration of terbinafine depending on age.
In pharmacokinetic studies of a single dose of terbinafine in patients with concomitant renal impairment (creatinine clearance <50 ml / min) and with liver diseases, the possibility of reducing terbinafine clearance by 50% was shown. Indications Mycoses caused by terbinafine-sensitive microorganisms: Onychomycosis caused by dermatophyte fungi. Mycosis of the scalp. Fungal infections of the skin – treatment of dermatomycoses of the trunk, legs, feet, as well as yeast infections of the skin caused by fungi of the genus Candida (for example, Candida albicans) – in cases where the localization, severity or prevalence of the infection makes oral therapy advisable. note: unlike the preparation ExifinВ® for local use, the preparation ExifinВ® for oral administration is not effective for multi-colored lichen. Contraindications Hypersensitivity to terbinafine or to any other component of the drug. Chronic or active liver disease. It is not recommended to use Exifin® in patients with impaired renal function (creatinine clearance of less than 50 ml / min or serum creatinine concentration of more than 300 μmol / l), since the use of the drug in this category of patients is not well understood. Children weighing less than 40 kg for this dosage. If you have one of these diseases, be sure to consult your doctor before using the drug. Caution must be exercised when using the drug in patients with inhibition of bone marrow hematopoiesis, cutaneous lupus erythematosus, or systemic lupus erythematosus. The drug should be used with caution in patients with concomitant diseases such as psoriasis or lupus erythematosus due to the possible exacerbation of these diseases. Use during pregnancy and lactation Data from experimental studies do not suggest that there are adverse effects with respect to toxic effects on the fetus. Since the clinical experience with the drug in pregnant women is very limited, the drug should not be used during pregnancy, unless the expected benefits of the therapy to the mother outweigh the potential risk to the fetus. Terbinafine is excreted in breast milk, so women who are taking ExifinВ® by mouth should not breast-feed. Impact on fertility There are no data on the effects of ExifinВ® on fertility in humans. Studies in rats did not reveal an undesirable effect of terbinafine on fertility and reproductive ability. Composition Each tablet contains: Active ingredient: terbinafine hydrochloride 281.31 mg (equivalent to 250 mg terbinafine). Excipients: microcrystalline cellulose (type 102) 47.00 mg, sodium carboxymethyl starch (sodium starch glycolate (type A)) 36.69 mg, pregelatinized starch 25.00 mg, colloidal silicon dioxide anhydrous 3.00 mg, magnesium stearate 7 , 00 mg. Dosage and administration of Duration of treatment depends on the indication and severity of the disease. The drug is used orally, regardless of the meal, washed down with water. It is advisable to use the drug at the same time. Adults and children weighing more than 40 kg 250 mg once a day. Recommended duration of treatment: Skin infections Dermatomycosis of the feet (interdigital, plantar or sock type): 2-6 weeks. Dermatomycosis of the trunk, legs: 2-4 weeks. Candidiasis of the skin: 2-4 weeks. Complete disappearance of the manifestations of infection and complaints associated with it can occur no earlier than a few weeks after mycological cure. Infections of hair and scalp Mycosis of the scalp: 4 weeks. Mycoses of the scalp are observed mainly in children. Onychomycosis The duration of treatment in most patients is from 6 to 12 weeks. With onychomycosis of the hands, in most cases, 6 weeks of treatment is sufficient. With onychomycosis of the feet in most cases, 12 weeks of treatment is sufficient. Some patients who have a reduced nail growth rate may need longer treatment. The optimal clinical effect is observed several months after mycological cure and cessation of therapy. This is determined by the period of time that is necessary for the growth of a healthy nail. Use in the elderly There is no reason to assume that for the elderly it is necessary to change the dosage regimen of the drug or that they have side effects that differ from those of younger patients. In the case of the use of the drug in tablets in this age group, the possibility of concomitant impaired liver or kidney function should be considered. Use in children Use of the drug in children weighing less than 40 kg is contraindicated for this form of release due to the fact that the Exifin® 250 mg tablet does not have a separation risk. With a child weighing 40 kg or more, adult doses are recommended. Side effects Exifin® is generally well tolerated. Side effects are usually mild or moderate and are transient. The following are adverse events that were observed during clinical trials or in the post-registration period. In assessing the incidence of side effects, the following gradations were used: “very often” ( 1/10), “often” ( 1/100 – <1/10), “infrequently” ( 1/1000 - <1/100 ), “Rarely” ( 1/10000 - <1/1000), “very rare” (<1/10000), including individual messages. Disorders of the blood and lymphatic system Infrequently – anemia is very rare – neutropenia, agranulocytosis, pancytopenia, thrombocytopenia. Immune system disorders Very rarely – anaphylactoid reactions (including angioedema) skin and systemic lupus erythematosus (or their exacerbation). Mental disorders Often – depression infrequently – anxiety. Disturbances from the nervous system Very often – headache often – dizziness, impaired taste sensations, up to their loss (usually recovery occurs within a few weeks after stopping treatment). There are separate reports of cases of prolonged violations of taste sensations. In some cases, depletion was noted during the administration of the drug. Infrequently: paresthesia, hypesthesia. Disorders of the organ of vision Infrequently – impaired vision. Hearing disorders and labyrinthine disorders Infrequently – tinnitus. Hepatic and biliary tract disorders Rarely, hepatobiliary dysfunction (predominantly cholestatic in nature), including liver failure, including very rare cases of severe liver failure (some fatal or requiring liver transplantation in most cases when liver failure has developed , patients had serious concomitant systemic diseases and a causal relationship of liver failure with terbinafine was doubtful), hepatitis, jaundice, cholestasis, increased activity of “liver” enzymes. Digestive system disorders Very often – bloating, loss of appetite, dyspepsia, nausea, mild abdominal pain, diarrhea. Disorders of the skin and subcutaneous tissue Very often – rash, urticaria infrequently – photosensitivity reactions are very rare – Stevens-Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, erythema multiforme, toxic skin rash, exfoliative dermatitis, dermatitis psoriasis, dermatitis bermatitis, rashes on the skin or exacerbation of psoriasis, alopecia. Violations of the musculoskeletal and connective tissue Very often – arthralgia, myalgia. General disorders Often – a feeling of tiredness infrequently – fever. Laboratory and instrumental data Infrequently – weight loss (secondary to impaired taste). Based on spontaneous messages received in the post-registration period, and literature data, the following adverse events have been identified whose frequency, due to an inaccurate number of patients, cannot be established: Immune system disorders: anaphylactic reactions, a syndrome similar to serum sickness. Disorders of the organ of vision: blurred vision, decreased visual acuity. Disorders of the skin and subcutaneous tissues: drug rash with eosinophilia and systemic symptoms (rash, swelling, fever and swollen lymph nodes). Hearing impairment and labyrinth disorders: hearing loss, hearing impairment. Disorders of the vessels: vasculitis. Disorders of the nervous system: loss of smell, including for a long period of time, decrease in smell. Disorders of the digestive system: pancreatitis. Disorders of the musculoskeletal and connective tissue: rhabdomyolysis. General Disorders: Flu-like syndrome. Laboratory and instrumental data: increased serum creatine phosphokinase activity. If any of the side effects indicated in the instructions are aggravated, or you notice any other side effects not listed in the instructions, inform your doctor. Drug Interaction Practically does not affect the clearance of drugs metabolised by cytochrome P450 (eg cyclosporine, terfenadine, tolbutamide, triazolam, oral contraceptives). Inhibits CYP2D6 isoenzyme and inhibits metabolism of drugs such as tricyclic antidepressants and selective serotonin uptake blockers (eg desipramine, fluvoxamine), beta-blockers (metoprolol, propranolol), antiarrhythmic agents, antiarrhythmic agents ) and antipsychotics (eg chlorpromazine, haloperidol). CYP450 enzyme inducers (eg rifampicin) can accelerate the elimination of terbinafine from the body. CYP450 inhibitor drugs (eg cimetidine) can slow the metabolism and excretion of terbinafine from the body. With these drugs, a dose adjustment of terbinafine may be required. Menstrual irregularities may occur with concomitant administration of terbinafine and oral contraceptives. Reduces caffeine clearance by 21% and extends its half-life by 31%. Does not affect clearance of antipyrine, digoxin, warfarin. Ethanol and other hepatotoxic agents increase the risk of hepatotoxic effects. Overdose Symptoms: nausea, vomiting, pain in the lower abdomen, in the epigastric region. Treatment: gastric lavage followed by activated charcoal and / or symptomatic therapy. Storage conditions At a temperature not exceeding 25C. Keep out of the reach of children! Shelf suitability 3 Year Deystvuyuschee substances Terbinafine tablet dosage form dosage form tablets
