TRIDERM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TRIDERM (TRIDERM).
TRIDERM is a combination antifungal, corticosteroid, and antibacterial. Clotrimazole inhibits fungal cytochrome P450 14α-demethylase, reducing ergosterol synthesis and disrupting fungal cell membrane integrity. Betamethasone dipropionate induces phospholipase A2 inhibitory proteins, suppressing prostaglandin and leukotriene synthesis, with anti-inflammatory, antipruritic, and vasoconstrictive effects. Gentamicin binds to bacterial 30S ribosomal subunit, causing misreading of mRNA and protein synthesis inhibition.
| Metabolism | Clotrimazole is metabolized in the liver to glucuronide conjugates. Betamethasone dipropionate is hydrolyzed to betamethasone, which is metabolized by CYP3A4. Gentamicin is not metabolized; it is excreted unchanged renally. |
| Excretion | Renal elimination of clobetasol propionate metabolites; betamethasone dipropionate metabolites excreted renally and fecally; gentamicin eliminated renally as unchanged drug (50-60%) and metabolites. Overall, renal excretion accounts for ~70-80% of total clearance, with biliary/fecal elimination of ~20-30%. |
| Half-life | Clobetasol propionate: ~3-5 hours (terminal). Betamethasone dipropionate: ~5-6 hours (terminal). Gentamicin: ~2-3 hours in patients with normal renal function (terminal half-life with clinical relevance for dosing interval). |
| Protein binding | Clobetasol propionate: 97-99% bound to corticosteroid-binding globulin (CBG) and albumin. Betamethasone dipropionate: ~64% bound to albumin. Gentamicin: <10% bound to plasma proteins. |
| Volume of Distribution | Clobetasol propionate: 2.4-2.7 L/kg (extensive tissue distribution). Betamethasone dipropionate: 1.4-1.8 L/kg (moderate distribution). Gentamicin: 0.2-0.4 L/kg (primarily extracellular fluid; higher in neonates). |
| Bioavailability | Topical: variable, 1-7% for corticosteroids depending on skin condition and site; gentamicin negligible absorption through intact skin, <0.1%. |
| Onset of Action | Topical application: anti-inflammatory effect within 1-2 hours; antimicrobial effect of gentamicin begins within 30-60 minutes. |
| Duration of Action | Topical application: clinical effect persists for 8-12 hours after a single application; with regular use, symptomatic relief lasts throughout treatment period. |
| Brand Substitutes | Novacor Cream, Clobital NM Cream, Zincoderm-GM Neo Cream, Cosvate NM Cream, Dermigen NF+ Cream |
Topical: apply a thin film to affected area twice daily. 1 mg/g betamethasone dipropionate + 10 mg/g clotrimazole + 0.5 mg/g gentamicin.
| Dosage form | CREAM |
| Renal impairment | No adjustment required for topical use. |
| Liver impairment | No adjustment required for topical use. |
| Pediatric use | Not recommended for children under 12 years; use only under specialist guidance. For ages 12-18: apply thin film twice daily for no more than 7 days. |
| Geriatric use | Use with caution due to increased risk of skin atrophy and systemic absorption; apply thin film twice daily for shortest duration possible. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TRIDERM (TRIDERM).
| Breastfeeding | Minimal systemic absorption after topical application. Betamethasone and gentamicin are excreted in breast milk in low amounts; M/P ratio not established for topical use. Use caution on large areas or broken skin to reduce infant exposure. Clotrimazole is not absorbed in significant amounts. Generally considered compatible with breastfeeding. |
| Teratogenic Risk | FDA Pregnancy Category C. First trimester: Corticosteroid component (betamethasone) associated with cleft palate in animal studies; risk in humans considered low at typical doses. Clotrimazole: no known teratogenic risk. Gentamicin: aminoglycosides can cause fetal ototoxicity if systemically absorbed, but topical application yields minimal systemic exposure. Second and third trimesters: Topical corticosteroids may cause fetal growth restriction and adrenal suppression if used extensively on large areas or under occlusion; avoid prolonged use. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
["Known hypersensitivity to clotrimazole, betamethasone dipropionate, gentamicin, or any component of the formulation","Perianal or genital pruritus without inflammation","Non-sterile skin conditions such as vaccinia, varicella, or herpes simplex","Fungal infections of the nails or scalp","Patients who are immunosuppressed or have systemic infections requiring systemic treatment"]
| Precautions | ["Systemic absorption of corticosteroids may cause reversible hypothalamic-pituitary-adrenal (HPA) axis suppression, Cushing's syndrome, hyperglycemia, and glucosuria","Prolonged use may lead to overgrowth of non-susceptible organisms including fungi; discontinue if superinfection occurs","Avoid use on skin areas with compromised circulation, on large body surface areas, or under occlusive dressings","Not for ophthalmic, oral, or intravaginal use","Use in pregnancy only if potential benefit justifies risk; avoid use in large amounts or for prolonged periods"] |
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| Fetal Monitoring | Monitor maternal blood glucose and blood pressure with prolonged use of high-potency corticosteroid on large areas. Assess for signs of maternal adrenal suppression (e.g., fatigue, hypotension) if used extensively. Fetal monitoring if used on >10% BSA or under occlusion in second/third trimester: ultrasound for growth restriction. No specific monitoring required for routine short-term small-area use. |
| Fertility Effects | No known significant impact on fertility. Systemic corticosteroids may affect ovulation but topical application has minimal systemic effect. Animal studies with high doses of betamethasone showed some reproductive toxicity, but relevance to humans at topical doses is negligible. |