MYCOLOG-II
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MYCOLOG-II (MYCOLOG-II).
MYCOLOG-II (nystatin and triamcinolone acetonide) combines nystatin, a polyene antifungal that binds to ergosterol in fungal cell membranes causing leakage of cellular contents, and triamcinolone acetonide, a corticosteroid that inhibits phospholipase A2, reducing inflammatory mediators.
| Metabolism | Nystatin is not absorbed systemically and is excreted unchanged in feces. Triamcinolone acetonide is metabolized hepatically via CYP3A4. |
| Excretion | Nystatin: negligible systemic absorption; >99% eliminated unchanged in feces via biliary/fecal route. Triamcinolone acetonide: ~30% renal, ~60% biliary/fecal as metabolites; <10% unchanged. |
| Half-life | Nystatin: not applicable (local action, negligible absorption). Triamcinolone acetonide: terminal elimination half-life approximately 2-4 hours in plasma; clinical effect duration relates to local tissue retention. |
| Protein binding | Nystatin: negligible protein binding. Triamcinolone acetonide: approximately 78-80% bound to corticosteroid-binding globulin and albumin. |
| Volume of Distribution | Nystatin: not applicable (topical, not absorbed). Triamcinolone acetonide: approximately 1.4 L/kg (varies with formulation); systemic distribution following topical application is minimal. |
| Bioavailability | Topical: nystatin bioavailability is negligible (<0.1%) via intact skin; triamcinolone acetonide systemic bioavailability is approximately 1-5% through intact skin, higher with occlusive dressings or inflamed skin. |
| Onset of Action | Topical: nystatin initiates antifungal effect within 24-48 hours; triamcinolone acetonide provides relief from inflammation within hours of application. |
| Duration of Action | Topical: nystatin requires continued application for full treatment (usually 2 weeks); triamcinolone acetonide duration of anti-inflammatory effect is 6-12 hours per application. |
| Molecular Weight | Nystatin: 926.1 Da; Triamcinolone acetonide: 434.5 Da. (Combination product, weighted average not applicable; provide both if needed, but per field requirement: 926.1 for nystatin, 434.5 for triamcinolone). |
Apply topically twice daily. Each gram contains 100,000 units nystatin and 0.1 mg triamcinolone acetonide.
| Dosage form | OINTMENT |
| Renal impairment | No dosage adjustment required for topical use; systemic absorption negligible. |
| Liver impairment | No dosage adjustment required for topical use; systemic absorption negligible. |
| Pediatric use | Apply topically twice daily; use smallest amount sufficient to cover affected area. Not recommended in children under 2 years due to triamcinolone content unless directed by physician. |
| Geriatric use | Use with caution due to increased risk of skin atrophy and systemic absorption from prolonged use; apply sparingly to small areas. |
| 1st trimester | Avoid due to potential teratogenicity from nystatin and triamcinolone; triamcinolone is a corticosteroid that may increase risk of oral clefts if used systemically. Topical use in limited areas may be considered if benefit outweighs risk, but generally not recommended. |
| 2nd trimester | Use only if clearly needed and limited to small areas; corticosteroids may affect fetal growth with prolonged use. Nystatin is not absorbed significantly, but triamcinolone absorption may occur with broken skin or occlusion. |
| 3rd trimester | Avoid prolonged or widespread use near term due to potential for fetal adrenal suppression from corticosteroids. Nystatin is safe, but triamcinolone may cause low birth weight or adrenal suppression. |
Clinical note
Comprehensive clinical and safety monograph for MYCOLOG-II (MYCOLOG-II).
| Placental transfer | Nystatin: negligible due to poor oral absorption. Triamcinolone: crosses placenta; degree depends on topical dose, surface area, and skin integrity. Systemic absorption after topical use is generally low (<1%) but can be higher with occlusion. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to nystatin, triamcinolone, or any componentViral skin infections (e.g., herpes simplex, varicella zoster)Fungal infections of the nail or scalp (not indicated)Untreated bacterial infections
| Precautions | Topical corticosteroids may cause reversible HPA axis suppression with potential glucocorticosteroid insufficiency after withdrawal, Risk of skin atrophy, striae, telangiectasias, and secondary infection, Use with caution in patients with impaired skin integrity or large surface area application |
| Food/Dietary | No known food interactions with topical Mycology-II. Avoid oral ingestion. |
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| Breastfeeding |
| Nystatin is not absorbed orally, thus unlikely to enter breast milk. Triamcinolone, as a topical corticosteroid, may be absorbed systemically and excreted into breast milk in small amounts, especially with large areas or occlusive use. Avoid application to breast area to prevent infant ingestion. Consider alternative with safer profile. |
| Lactation Rating | L3 (Moderately Safe) - Limited data suggests low risk but caution advised, especially with prolonged use or large areas. |
| Teratogenic Risk | Mycolog-II (nystatin/triamcinolone acetonide): No adequate studies in pregnant women. Nystatin is poorly absorbed and considered low risk. Triamcinolone acetonide is a corticosteroid; animal studies show increased risk of cleft palate at high doses. Risk cannot be ruled out; use only if benefit outweighs risk. |
| Fetal Monitoring | Monitor fetal growth if used extensively. Assess for signs of maternal adrenal suppression with prolonged use. |
| Fertility Effects | No specific data. Corticosteroids may impair fertility in animal studies; relevance unknown. |
| Clinical Pearls |
| Mycology-II is a combination antifungal cream containing nystatin and triamcinolone acetonide. Nystatin is effective only against Candida species; triamcinolone reduces inflammation and pruritus. Avoid use in fungal infections without inflammation, as corticosteroids can mask or worsen untreated mycosis. Do not apply to widespread areas or for prolonged periods due to risk of systemic corticosteroid absorption. Limit use to no more than 2 weeks. |
| Patient Advice | Apply a thin layer to affected area twice daily for no longer than 2 weeks. · Do not use on skin that is broken, blistered, or infected with bacteria or viruses. · Avoid contact with eyes, mouth, or vaginal area unless directed. · Do not cover the treated area with bandages or wraps unless instructed by your doctor. · Stop use and contact your doctor if symptoms persist or worsen after 2 weeks. |