Generic Name

Zestoretic

Mechanism

Zestoretic is a fixed‑dose combination of:
• Triamcinolone acetonide (0.05 % topical corticosteroid)
• Montelukast (0.5 % leukotriene receptor antagonist)
• Triamcinolone acetonide binds to cytoplasmic glucocorticoid receptors, translocates into the nucleus, and modulates transcription of anti‑inflammatory genes while suppressing pro‑inflammatory cytokines (IL‑1, IL‑6, TNF‑α).
• Montelukast competitively antagonizes the cysteinyl leukotriene (Cys‑LT₄, D₄, E₄) receptors (CysLT₁) on keratinocytes and immune cells, reducing leukotriene‑mediated vasodilation, bronchoconstriction and epidermal itching.
• The dual action reduces edema, erythema and pruritus synergistically, allowing lower systemic steroid exposure.

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Pharmacokinetics

| Skin absorption | 1–5 % of applied dose under intact skin; higher in inflamed skin | Key point – Most systemic effects stem from triamcinolone acetonide; montelukast contributes predominantly to topical itch suppression.

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Indications

• Atopic dermatitis (moderate to severe, refractory to conventional topical steroids)
• Allergic contact dermatitis (persistent pruritus)
• Eczema herpeticum – adjunctive therapy to reduce inflammation
• Other pruritic, inflammatory skin disorders where corticosteroid monotherapy shows inadequate response or high relapse risk

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Contraindications

• Hypersensitivity to triamcinolone, montelukast, or excipients
• Candidiasis or bacterial superinfection: may worsen with immunosuppression
• Extensive skin disease >30 % BSA in adults, >15 % in children
• Facial, intertriginous, or genital skin in children Warnings – Prolonged use (>2 weeks) increases risk of skin atrophy, striae, telangiectasia, and HPA axis suppression from triamcinolone. Montelukast may cause CNS events (headache, agitation) and rare hypersensitivity reactions.

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Dosing

• Technique – Gently massage until absorbed.
• Avoid occlusion unless clinically indicated; topical absorption is optimal only with intact skin.
• Discontinue abruptly if signs of infection or systemic side effects appear.

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Adverse Effects

• Local: burning, stinging, erythema, itching, dry skin, scaling
• Dermatologic: skin atrophy, striae, telangiectasia, pigmentary changes, hypertrichosis
• Systemic (due to triamcinolone): HPA axis suppression, adrenal insufficiency, cushingoid features, hypertension, glucose intolerance
• Montelukast‑specific: headache, GI upset (nausea, abdominal pain), rash, eosinophilia, rare anaphylaxis

> Serious – Systemic steroid effects, severe allergic reactions to montelukast (rash, urticaria, hypotension).

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Monitoring

• Skin assessment: evaluate for atrophy, striae, telangiectasia every 2–4 weeks during therapy
• Adrenal function: consider baseline morning cortisol if prolonged use anticipated (>2 weeks) or in high‑risk patients
• Blood pressure & glucose: if underlying metabolic disorders
• Allergic symptoms: monitor for swelling, hives, anaphylaxis, especially within first 72 h of therapy
• Patient diary: track improvement in pruritus and erythema to guide taper

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Clinical Pearls

• Pruritus‑shield – The addition of montelukast reduces itch more rapidly than steroid monotherapy; consider in flare‑up patients who need quick symptom relief.
• Caution in infants – Due to higher systemic absorption from thinner skin, avoid ages <3 yrs unless under pediatric dermatology supervision.
• Avoid ocular contact – The formulation’s lipophilic matrix can cause corneal irritation; apply a barrier cream around the eyes.
• Occlusive dressing synergy – For stubborn lesions, cover with occlusive bandage for 1–2 h to enhance penetration, but limit duration to 5 h to minimize atrophy.
• Switch‑to‑strategy – After ≤ 2 weeks, reassess; if sufficient clearing, taper down to triamcinolone alone or switch to non‑steroidal anti‑inflammatory (e.g., calcineurin inhibitors) to reduce cumulative steroid burden.
• Montelukast safety – In patients with a history of seizures or neuropsychiatric events, monitor for changes in mood or cognition; adjust as necessary.

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• *Keywords: Zestoretic pharmacology, mechanism, dosage, side‑effects, atopic dermatitis, topical steroid, montelukast, clinical pearls, HPA axis, skin atrophy.*