Mometasone inhalers

Generic Name: Mometasone furoate
Pharmacologic Class: Inhaled corticosteroid (ICS)
Therapeutic Class: Anti-inflammatory agent for asthma and chronic obstructive pulmonary disease (COPD)
ATC Code: R03BA07

Brand Names: Asmanex Twisthaler, Asmanex HFA (inhalation aerosol), Elocon (topical), Nasonex (nasal)

Available Inhaler Devices:
– Asmanex Twisthaler: Dry Powder Inhaler (DPI)
– Asmanex HFA: Metered Dose Inhaler (MDI)
– Strengths: 100 mcg, 200 mcg, 220 mcg, 400 mcg per actuation
– Delivered dose per inhalation: Varies by product and regional formulation
Prescription Status: Rx only

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Mechanism of Action

Mometasone furoate is a synthetic corticosteroid with potent anti-inflammatory activity in the airways. It acts locally in the lungs to:

• Suppress inflammatory cell recruitment (e.g., eosinophils, macrophages, mast cells)

• Inhibit inflammatory cytokines and mediators (e.g., IL-4, IL-5, TNF-α, prostaglandins, leukotrienes)

• Reduce airway hyper-responsiveness and mucus production

• Restore β2-adrenoceptor responsiveness to bronchodilators

There is minimal systemic absorption, reducing the risk of systemic corticosteroid-related adverse effects.

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Therapeutic Indications

1. Asthma (maintenance treatment)
   – Adults and children ≥4 years
   – Monotherapy or adjunct to long-acting β2-agonists (LABA)

2. COPD (off-label in some countries; supported in combination therapy)
   – Not FDA-approved for COPD monotherapy

3. Prevention of exercise-induced bronchospasm (EIB)
   – Indirect use by maintaining airway stability in chronic asthma

4. Reduction of oral corticosteroid dependence in severe asthma

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Dosage and Administration

Asmanex Twisthaler (DPI):

Adults and adolescents ≥12 years:

• Starting dose (mild/moderate asthma): 220 mcg once daily, preferably in the evening

• Severe asthma: 220 mcg twice daily

• Maximum: 880 mcg/day (divided doses)

Children 4–11 years:

• 110 mcg once daily in the evening

• Not recommended below 4 years

Asmanex HFA (MDI):

Adults and children ≥12 years:

• 100–200 mcg twice daily

• Maximum: 400 mcg twice daily (800 mcg/day)

Children 5–11 years:

• 100 mcg twice daily

Administration Tips:

• Rinse mouth and spit after each use to prevent oral thrush

• Use consistently, even if symptoms are controlled

• Not intended for acute bronchospasm – not a rescue inhaler

• If a dose is missed, use as soon as remembered unless it's close to the next dose

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Pharmacokinetics

• Bioavailability (systemic): <1% (DPI), ~20% (HFA)

• Time to onset: Within 24 hours; peak effect in 1–2 weeks

• Half-life: 5.8 hours

• Metabolism: Hepatic via CYP3A4

• Excretion: Feces (as metabolites), minimal renal elimination

• Protein binding: ~98–99%

• Peak plasma concentration: Low even at high inhaled doses

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Contraindications

• Hypersensitivity to mometasone or formulation components

• Status asthmaticus or acute bronchospasm (not a reliever)

• Severe milk protein allergy (Twisthaler contains lactose)

• Children under 4 years (Twisthaler) or under 5 years (HFA)

• Concomitant untreated respiratory infection (viral, bacterial, fungal, or TB)

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Warnings and Precautions

1. Oropharyngeal candidiasis (thrush):
   – Advise rinsing mouth after inhalation
   – Treat with topical antifungal if it occurs

2. Systemic corticosteroid effects (rare but possible):
   – Adrenal suppression (especially at high doses)
   – Cushingoid features
   – Growth retardation in children

3. Respiratory infection risk:
   – Slight increase in bacterial/viral infections
   – Avoid exposure to measles/chickenpox

4. Paradoxical bronchospasm:
   – Rare, life-threatening
   – Discontinue if wheezing worsens after inhalation

5. Impaired wound healing:
   – Caution in patients with recent respiratory tract surgery or trauma

6. Visual disturbances:
   – Cataracts and glaucoma (rare with long-term high-dose use)

7. Growth suppression in pediatric patients:
   – Monitor height annually
   – Use lowest effective dose

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Adverse Effects

Common (≥1%):

• Headache

• Nasal congestion or pharyngitis

• Cough

• Dysphonia (hoarseness)

• Oral candidiasis (thrush)

• Upper respiratory tract infections

Uncommon (<1%):

• Nausea

• Myalgia

• Sinusitis

• Skin rash

• Bronchospasm

• Epistaxis

Rare:

• Adrenal insufficiency

• Behavioral changes (irritability, hyperactivity) in children

• Growth suppression

• Increased intraocular pressure or cataracts

• Anaphylaxis (extremely rare)

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Drug Interactions

Interacting Agent	Potential Effect	Clinical Advice
CYP3A4 inhibitors (e.g., ketoconazole, ritonavir)	↑ Mometasone levels → systemic side effects	Monitor or avoid long-term co-administration
Other inhaled corticosteroids	Cumulative systemic effects	Avoid duplication unless justified
Live vaccines	Potential immunosuppressive interference	Postpone vaccination if on high-dose ICS
LABA combinations	Often co-prescribed (e.g., formoterol)	Use as fixed combination (when indicated)

Pregnancy and Lactation

Pregnancy:
– Category C (US FDA)
– Inhaled mometasone is considered low risk when used in recommended doses
– Avoid high doses or systemic exposure unless benefit outweighs risk

Lactation:
– Unknown if excreted in human milk
– Inhaled route minimizes systemic exposure; likely low risk
– Prefer lowest effective dose

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Use in Special Populations

• Pediatrics (≥4 years): Effective for asthma control with dose monitoring

• Geriatrics: No specific precautions; monitor for systemic steroid effects

• Renal impairment: No adjustment necessary

• Hepatic impairment: Use with caution; impaired metabolism via CYP3A4 may increase systemic exposure

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Monitoring Parameters

• Symptom control (wheezing, night symptoms, reliever use)

• Frequency of exacerbations

• Growth in children

• Oropharyngeal examination for thrush

• Adrenal function (especially at high doses)

• Intraocular pressure (long-term use)

• Spirometry (FEV1, PEFR for asthma control)

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Comparison to Other ICS Agents

Feature	Mometasone (Asmanex)	Fluticasone (Flovent)	Budesonide (Pulmicort)
Potency	High	High	Moderate
Systemic absorption	Very low (<1%)	Low (~10%)	Moderate (~30%)
Onset of effect	12–24 hours	12–24 hours	Within 12 hours
Dosing frequency	Once or twice daily	Twice daily	Once or twice daily
Growth suppression risk	Low at standard dose	Similar	Slightly higher

Mometasone is favored when minimal systemic absorption is prioritized, making it suitable for long-term monotherapy or combination therapy in moderate-to-severe asthma.

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Patient Counseling Points

• Not a rescue inhaler – does not relieve sudden symptoms

• Use daily, even when asymptomatic

• Rinse mouth after inhaling to prevent thrush

• Follow device-specific instructions (Twisthaler vs HFA)

• Keep track of doses left; discard when empty even if powder remains (Twisthaler)

• Store inhaler dry, away from moisture and heat

• If symptoms worsen or no improvement in 1–2 weeks, seek medical advice

• Carry a rescue inhaler (e.g., salbutamol) at all times

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Storage Instructions

• Twisthaler: Store at room temperature (15–30°C), keep cap on to prevent moisture

• HFA Inhaler: Do not puncture or expose to heat above 49°C (120°F)

• Discard 45 days after opening (Twisthaler) or after labeled number of actuations