Omastin 150

Indications

Omastin is prescribed for the treatment of various fungal infections, including:

• Vaginal Candidiasis
• Oropharyngeal Candidiasis
• Oesophageal Candidiasis
• Tinea Infections: Tinea corporis, Tinea cruris, Tinea pedis, and other tinea types
• Kerion
• Pityriasis Versicolor
• Onychomycosis
• Invasive Candidal Infections and Cryptococcal Infections, including cryptococcal meningitis
• Prevention of Cryptococcal Meningitis
• Preventive Treatment for fungal infections in immunocompromised patients
• Systemic Candidiasis and Cryptococcal Infections

Additional Indications:

• Fungal Urinary Tract Infections
• Disseminated Candidiasis
• Prophylaxis for fungal infections in neutropenic cancer patients
• Acute Treatment of other systemic fungal infections, such as coccidioidomycosis and histoplasmosis

Pharmacology

Fluconazole, the active ingredient in Omastin, is a triazole antifungal that inhibits fungal cytochrome P-450 dependent enzymes. This enzyme system is crucial for the synthesis of ergosterol, a key component of the fungal cell membrane.

Dosage & Administration

For Adults:

• Vaginal Candidiasis: 150 mg as a single dose.
• Oropharyngeal Candidiasis: 200 mg on the first day, followed by 100 mg daily for 14 days.
• Oesophageal Candidiasis: 200 mg on the first day, followed by 100 mg daily for 14-30 days.
• Tinea Infections: 150 mg weekly for 4-6 weeks.
• Kerion: 50 mg daily for 20 days.
• Pityriasis Versicolor: 400 mg as a single dose.
• Onychomycosis: 150 mg weekly for up to 12 months.
• Invasive Candidal and Cryptococcal Infections: 400 mg on the first day, then 200-400 mg daily, orally or via IV infusion.
• Prevention of Cryptococcal Meningitis: 200 mg daily, orally or via IV infusion.
• Preventive Treatment for Immunocompromised Patients: 50-400 mg daily, orally or via IV infusion.

For Children (over 1 year):

• Superficial Candidiasis: 1-2 mg/kg daily.
• Systemic Candidiasis & Cryptococcal Infections: 3-6 mg/kg daily.

In severe, life-threatening infections, doses up to 12 mg/kg daily may be used for children aged 5-13 years (maximum 400 mg daily).

Dosage for Children (by weight):

• 1 year (9 kg): ½ measuring spoonful
• 1-2 years (12 kg): 1 measuring spoonful
• 2-3 years (14 kg): 1½ measuring spoonful
• 3-4 years (16 kg): 2 measuring spoonfuls
• 4-6 years (20 kg): 2½ measuring spoonfuls

Use in Specific Populations

Elderly Patients: Use the standard dose if there is no evidence of renal impairment.

Renal Impairment: Adjust dosage for multiple-dose therapy based on creatinine clearance:

• CrCl >41 ml/min: 24-hour dosage interval
• CrCl 21-40 ml/min: 48-hour dosage interval
• CrCl 10-20 ml/min: 72-hour dosage interval
• Patients on Dialysis: One dose after each dialysis session

Children: Doses up to 12 mg/kg may be used, as renal clearance in children can be faster than in adults.

Interaction

Fluconazole may interact with various medications:

• Warfarin: May increase prothrombin time; monitor closely.
• Oral Sulphonylureas: May enhance hypoglycemic effects; monitor for hypoglycemia.
• Hydrochlorothiazide: May increase fluconazole levels; no dose adjustment necessary but monitor levels.
• Phenytoin: May increase phenytoin levels significantly.
• Rifampicin: May reduce fluconazole levels; consider dose adjustment.
• Oral Contraceptives: Minor effect on hormone levels; unlikely to impact efficacy.
• Cyclosporin: May increase cyclosporin levels; monitor concentrations.

Food and Other Substances: No significant impairment of fluconazole absorption with food, cimetidine, antacids, or total body irradiation.

Theophylline: Fluconazole may decrease theophylline clearance; monitor for toxicity.

Contraindications

Omastin should not be used in individuals with a known hypersensitivity to fluconazole or other triazole antifungals.

Side Effects

Omastin is generally well-tolerated. Common side effects include gastrointestinal symptoms such as nausea, abdominal discomfort, diarrhea, and flatulence. Rare side effects include rash and, very rarely, anaphylaxis.

Pregnancy & Lactation

Fluconazole has shown adverse effects in animal studies only at doses causing maternal toxicity. Use during pregnancy is not recommended. Adequate contraception should be used if fluconazole is prescribed to women of childbearing potential.

Lactation: Not recommended due to its presence in breast milk at levels similar to plasma.

Precautions & Warnings

Monitor for hepatic, renal, and hematological abnormalities in patients with serious underlying conditions. Discontinue if severe skin reactions like Stevens-Johnson Syndrome or toxic epidermal necrolysis occur.

Use in Special Populations

• Elderly: Use the standard dose if renal function is normal.
• Renal Impairment: Adjust dosage according to creatinine clearance as detailed above.

Overdose Effects

Supportive measures and symptomatic treatment are recommended for overdose. Fluconazole is primarily excreted in urine, so forced diuresis may aid in elimination. Hemodialysis can reduce plasma levels by approximately 50%.

Therapeutic Class

Antifungal medications for systemic and superficial mycoses.

Storage Conditions

Store in a dry place, away from light and heat. Keep out of reach of children.