Terbinafin cream 1%, 15g

Composition

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of 1 g of cream contains:  

Active ingredients:

terbinafine hydrochloride 10 mg;

Auxiliary substances:

benzyl alcohol,

polysorbate 60 (tween 60),

sorbitan monostearate,

cetyl alcohol,

isopropyl myristate,

cetyl palmitate,

sodium hydroxide,

purified water.

Pharmacological action

Terbinafine is an antifungal agent. It has a broad 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;
• yeast fungi of the genus Candida (e. g., C. albicans) and Pityrosporum.

In low concentrations, terbinafine has a fungicidal effect against dermatophytes, mold and some dimorphic fungi. Activity against yeast fungi, depending on their type, can be fungicidal or fungistatic.

The mechanism of action is associated with specific suppression of the early stage of sterol biosynthesis in the fungal cell. This leads to ergosterol deficiency and intracellular squalene accumulation, which causes fungal cell death. The action of terbinafine is carried out by inhibiting the enzyme squalene oxidase in the cell membrane of the fungus. This enzyme does not belong to the cytochrome P450 system. Terbinafine does not significantly affect the metabolism of hormones or other medications.

Pharmacokinetics

When terbinafine is administered orally, concentrations of the drug are created in the skin, hair and nails that provide a fungicidal effect.

After a single oral dose of 250 mg of terbinafine, its maximum plasma concentration is reached in 2 hours and is 0.97 mcg / ml. The half-absorption period is 0.8 hours, and the half-distribution period is 4.6 hours. Although the bioavailability of terbinafine modestly changes under the influence of food, but not to such an extent that a dose adjustment of the drug is required.

Terbinafine is largely bound to plasma proteins (99%). It quickly penetrates the dermal layer of the skin and concentrates in the lipophilic stratum corneum. Terbinafine also penetrates the secret of the sebaceous glands, which leads to the creation of high concentrations in hair follicles, hair and in the skin rich in sebaceous glands. It is also shown that terbinafine penetrates the nail plates in the first few weeks after the start of therapy.

Terbinafine is metabolized rapidly and significantly with the participation of at least seven cytochrome P 450 isoenzymes, with the main role played by the isoenzymes CYP2C9, CYP1A2, CYP3A4, CYP2C8 and CYP2C19. As a result of biotransformation of terbinafine, metabolites are formed that do not have antifungal activity and are mainly excreted in the urine. The final elimination half-life is 17 hours. There is no evidence of accumulation of the drug in the body. There were no changes in the steady-state plasma concentrations of terbinafine depending on age, but in patients with impaired renal or hepatic function, the rate of drug elimination may be slowed, which leads to higher concentrations of terbinafine in the blood.

With topical application of the spray or cream, less than 5% of the dose is absorbed, so the systemic effect of the drug is minimal.

Indications

• Mycoses of the scalp (trichophytosis, microsporia).
• Fungal diseases of the skin and nails (onychomycosis) caused by Trychophyton (T. rubrum, T. mentagrophytes, T. verrucosum, T. violaccum), Microsporum (M. sapis, M. gypseum) and Epidermophyton floccosum.
• Severe, widespread dermatomycosis of smooth skin of the trunk and limbs, requiring systemic treatment.
• Candidiasis of the skin and mucous membranes.

Use during pregnancy and lactation

No teratogenic properties of terbinafine were found in experimental studies.

The use of the drug during pregnancy is possible in cases where the intended benefit to the mother exceeds the possible risk to the fetus. Terbinafine is excreted in breast milk.

If it is necessary to use the drug during lactation, the question of stopping breastfeeding should be decided.

Contraindications

Hypersensitivity, severe hepatic-cellular and renal insufficiency, blood diseases, tumors, metabolic diseases, vascular pathology of the extremities, pregnancy, breast-feeding, children (up to 12 years).

Side effects

Sensation of heaviness and pain in the epigastric region, impaired taste, decreased appetite, nausea, diarrhea, cholestasis, neutropenia, thrombocytopenia, allergic skin reactions; burning sensation, redness of the skin and itching in the area of applying the cream.

Interaction

No drug interactions are known for terbinafine ointment/cream.

How to take, course of use and dosage

Terbinafine can be applied to the skin 1 or 2 times a day. Before applying, it is necessary to clean and dry the affected areas. Apply a thin layer on the affected skin and adjacent areas and rub lightly. For infections accompanied by diaper rash (under the mammary glands, in the interdigital spaces, between the buttocks, in the groin area), the places of application of the cream can be covered with gauze, especially at night.

Average duration of treatment:

• dermatomycosis of the trunk, limbs, legs: 1-2 weeks;
• dermatomycosis of the feet: 2-4 weeks;
• candidiasis of the skin: 1-2 weeks;
• multi-colored lichen: 2 weeks;
• mycosis of nail plates: 3-6 months.

A decrease in the severity of clinical manifestations is usually noted in the first days of treatment. In case of irregular treatment or premature discontinuation, there is a risk of recurrent infection. If there are no signs of improvement after two weeks of treatment, the diagnosis should be verified.

Use of the drug in the elderly: There is no reason to assume that the elderly need to change the dosage of the drug or that they have side effects that differ from those in younger patients.

Children: The experience of using it in children is limited.

Overdose

Symptoms:

headache, dizziness, nausea, vomiting, epigastric pain, frequent urination, rash.

Treatment:

measures to remove the drug (gastric lavage, taking activated charcoal); if necessary, symptomatic maintenance therapy.

Storage conditions

In a dry place, at a temperature not exceeding 25°C

Shelf life

3 years

Active ingredient

Terbinafine

Dosage form

cream

Description

For adults

Indications

Skin Fungus, Fungus