Mycobus Tm

Uses

Mometasone furoate is a corticosteroid used to treat asthma, allergic rhinitis, nasal congestion, nasal polyps, dermatitis, and pruritus.

There are 3 formulations of mometasone furoate with various indications. The inhaler is indicated for prophylaxis of asthma in patients ≥4 years. The nasal spray is indicated for treating nasal symptoms of allergic rhinitis in patients ≥2 years, treating symptoms of nasal congestion from seasonal allergic rhinitis in patients ≥2 years, treating nasal polyps in patients ≥18 years, and prophylaxis of seasonal allergic rhinitis in patients ≥12 years. The ointment is indicated for symptomatic treatment of dermatitis and pruritis in patients ≥2 years.

Terbinafine cream is used for the treatment of the following dermatological infections: interdigital tinea pedis (Athlete’s foot), tinea cruris (jock itch) or tinea corporis (ring worm) due to susceptible organisms and planter tinea pedis (mocasin type) due to Trichophyton spp.

Terbinafine tablet is used for the treatment of onychomycosis of the toe nail or finger nail due to dermatophytes and also by non-dermatophyte fungi.

Mycobus Tm is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Asthma, Dermatitis, Dermatitis, Eczematous caused by superficial Fungal skin infection, Moderate to Severe Plaque Psoriasis, Polyps, Nasal, Pruritus, Psoriasis, Psoriasis, Moderate to Severe, Seasonal Allergies, Skin Diseases, Eczematous, Skin InfectionsOnychomycosis, Pityriasis versicolor, Sporotrichosis, Tinea Capitis, Tinea Corporis, Tinea Cruris, Tinea Pedis, Cutaneous candidiasis, Severe Tinea Corporis, Severe Tinea Cruris, Severe Tinea Pedis

How Mycobus Tm works

In asthma, mometasone is believed to inhibit mast cells, eosinophils, basophils, and lymphocytes. There is also evidence of inhibition of histamine, leukotrienes, and cytokines.

Corticosteroids diffuse across cell membranes into the cytosol of cells where they bind to glucocorticoid receptors to produce their activity. Mometasone furoate has a particularly high receptor affinity compare to other corticosteroids, 22 times higher than that of dexamethasone. Mometasone furoate binding to a glucocorticoid receptor causes conformational changes in the receptor, separation from chaperones, and the receptor moves to the nucleus. Once at the nucleus, receptors dimerize and bind to a DNA sequence known as the glucocorticoid response element which either increases expression of anti-inflammatory molecules or inhibits expression of pro-inflammatory molecules (such as interleukins 4 and 5). Mometasone furoate also reduces inflammation by blocking transcription factors such as activator-protein-1 and nuclear factor kappa B (NF-kappaB).

Terbinafine inhibits the enzyme squalene monooxygenase (also called squalene epoxidase), preventing the conversion of squalene to 2,3-oxydosqualene, a step in the synthesis of ergosterol. This inhibition leads to decreased ergosterol, which would normally be incorporated into the cell wall, and accumulation of squalene.

Generation of a large number of squalene containing vesicles in the cytoplasm may leach other lipids away from, and further weaken, the cell wall.

Dosage

Mycobus Tm dosage

Topical application:

Terbinafine cream to affected areas once or twice daily for 1-2 weeks may be adequate for fungal infections of the skin but certain infections may require oral Terbinafine tablet therapy.Usual duration of treatment of Terbinafine cream:

• In Tinea corporis and Tinea cruris: 1-2 weeks.
• In Tinea pedis: 2-4 weeks (One week of treatment will normally suffice if the cream is applied twice daily.).
• In Cutaneous candidiasis: 1-2 weeks
• In Pityriasis (tinea) versicolor: 2 weeks.

To prevent relapses in fungal infection, treatment should be continued for a adequate length of time. To apply Terbinafine cream clean and dry the affected areas thoroughly and apply the cream once or twice a day to the affected skin and surrounding area in a thin layer and rub in lightly. In the case of intertriginous infections the application may be covered with a gauze strip, especially at night.

Oral administration:

Terbinafine tablet is essential for hair or nail infections:

• The usual oral dose: Terbinafine 250 mg daily for 2 to 12 weeks depending upon the infection.
• Finger nail onychomycosis: Terbinafine 250 mg once daily for 6 weeks.
• Toe nail onychomycosis: Terbinafine 250 mg once daily for 12 weeks.

Side Effects

Terbinafine Tablet: Abdominal discomfort, anorexia, nausea, diarrhoea, headache, rash and urticaria occasionally with arthralgia or myalgia. Less frequently taste disturbance. Rarely liver toxicity, photosensitivity, serious skin reactions etc.

Terbinafine Cream: Redness, itching, or stinging; rarely allergic reactions.

Toxicity

Overdose with a mometasone furoate inhaler may occur with chronic overuse. Symptoms of chronic overuse may present as hypercorticism and adrenal suppression, and patients may not require any more treatment than monitoring.

In animal studies of pregnancy, some fetal toxic effects were seen at or above the maximum recommended human dose, though rodents are more sensitive to these effects than humans. The benefits and risks of use should be considered in pregnant patients

It is unknown if mometasone furoate is excreted in breast milk but other corticosteroids are and therefore caution should be exercised when administering to nursing mothers.

Safety and effectiveness in pediatric populations has been established through clinical trials, though there may be a reduction in expected growth of about 1cm per year depending on the dose and duration of treatment. Pediatric patients should be titrated to the lowest effective dose for mometasone furoate inhalers.

A trial of geriatric patients showed no difference in safety or efficacy compared to younger patients, however patients of an even greater age may still be more sensitive to mometasone furoate.

The use of a mometasone furoate inhaler in moderate or severe hepatic impairment rarely leads to detectable plasma concentrations though caution may be prudent with increasing degrees of severity.

The effects of mometasone furoate in renal impairment, and across gender and race have not been studied.

The subcutaneous LD₅₀ in rats and mice is >2g/kg. The TDLO for women is 210mg/kg/6W.

Overdose data with terbinafine is rare, however symptoms are expected to be nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache. Treat overdose with activated charcoal as well as symptomatic and supportive therapy.

Precaution

Terbifine cream is for external use only. Contact with eyes should be avoided.Good general hygiene is necessary in conjunction with the use of Terbinafine in order to prevent reinfection (eg. from underwear, socks,shoes etc).

Terbinafine tablet is not recommended for patients with chronic or active liver disease. Before prescribing terbinafine, pre-existing liver disease should be assessed. Hepatotoxicity may occur in patients with and without pre-existing liver disease. Pretreatment serum transaminase (ALT and AST) tests are advised for all patients before taking terbinafine tablets.

Interaction

In vivo studies have shown that terbinafine is an inhibitor of the CYP450 2D6 isozyme. Drugs predominantly metabolized by the CYP450 2D6 isozyme include the following drug classes: tricyclic antidepressants, selective serotonin reuptake inhibitors, beta-blockers, antiarrhythmics class 1C (e.g., flecainide and propafenone) and monoamine oxidase inhibitors Type B. Co-administration of terbinafine should be done with careful monitoring and may require a reduction in dose of the 2D6-metabolized drug.

Volume of Distribution

Steady state volume of distribution of 152L.

A single 250mg oral dose of terbinafine has a volume of distribution at steady state of 947.5L or 16.6L/kg.

Elimination Route

Oral terbinafine is >70% absorbed but only 40% bioavailable after first pass metabolism, reaching a C_max of 1µg/mL with a T_max of 2 hours an an AUC of 4.56µg*h/mL. Over the course of a week, 1% topical terbinafine's C_max increases from 949-1049ng/cm²

Half Life

The terminal half life of an inhaled dose is approximately 5 hours though it has been reported as 5.8 hours by other sources.

Oral terbinafine has an effective half life of approximately 36 hours. However, the terminal half life ranges from 200-400 hours as it distributes into skin and adipose tissue. 1% topical terbinafine's half life increases over the first seven days from approximately 10-40 hours.

Clearance

The clearance rate of mometasone furoate is not readily available, though it may be close to 90L/h.

A single 250mg oral dose of terbinafine has a clearance of 76L/h or 1.11L/h/kg.

Elimination Route

For an inhaled dose, approximately 74% is excreted in the feces and 8% is excreted in the urine.

Terbinafine is approximately 80% eliminated in urine, while the remainder is eliminated in feces. The unmetabolized parent drug is not present in urine.

Pregnancy & Breastfeeding use

Terbinafine tablet: There are no adequate and well controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, and because treatment of onychomycosis can be postponed until after pregnancy is completed, it is recommended that terbinafine not be initiated during pregnancy. After oral administration, terbinafine is present in breast milk of nursing mothers. Treatment with terbinafine in not recommended in nursing mothers.

Terbinafine cream: Foetal toxicity and fertility studies in animals suggest no adverse effects. There is no clinical experience with terbinafine in pregnant women; therefore, unless the potential benefits outweigh any potential risk, terbinafine should not be administered. Terbinafine is excreted in breast milk and therefore mothers should not receive terbinafine treatment whilst breast-feeding.

Contraindication

Hypersensitivity to Terbinafine or any of the excipients in thepreparation

Special Warning

Use in Children: Terbinafine cream appears to be an effective and well-tolerated treatmenr of tinea corposis and tinea cruris in children.

Use in Elderly: Terbinafine appears to be safe in the elderly. The dose should be reduced by half if significant hepatic or renal impairment is present.

Acute Overdose

Clinical experience regarding overdose with terbinafine tablets is limited. Doses up to 5 grams (20 times the therapeutic daily dose) have been taken without inducing serious adverse reactions. The symptoms of overdose included nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache.

Storage Condition

Store in a cool and dry place, protected from light.

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