What is Mometasone?
Mometasone furoate is a potent synthetic corticosteroid with strong anti-inflammatory properties, available in multiple formulations (nasal spray, topical, and inhaled) for treating allergic rhinitis, nasal polyps, skin conditions, and asthma. 1, 2, 3
Drug Classification and Mechanism
Mometasone furoate is a synthetic glucocorticoid with exceptionally high receptor binding affinity—approximately 12 times that of dexamethasone, 7 times that of triamcinolone acetonide, 5 times that of budesonide, and 1.5 times that of fluticasone 2
The drug exerts its anti-inflammatory effects by inhibiting multiple inflammatory cell types (mast cells, eosinophils, neutrophils, macrophages, lymphocytes) and mediators (histamine, eicosanoids, leukotrienes, cytokines) 2
Mometasone specifically inhibits pro-inflammatory Th2 cytokines and blocks leukotriene synthesis, which reduces vascular permeability and decreases the intensity of allergic reactions 1, 4
A key advantage is minimal systemic activity due to low bioavailability, making it safer for long-term use compared to other corticosteroids 1, 2
Available Formulations
Nasal Spray (Intranasal)
Mometasone furoate nasal spray delivers 50 μg per spray and is indicated for seasonal allergic rhinitis, perennial allergic rhinitis, nasal polyps, and post-viral acute rhinosinusitis 1, 5
Standard dosing for adults is 200 μg once or twice daily (2 sprays per nostril), with the American Academy of Otolaryngology recommending 200 μg twice daily for up to 12 months after sinus surgery to reduce polyp recurrence from 20% to 2-3% 5
For children as young as 2 years, the recommended dose is 1 spray per nostril daily (50 μg per spray) 6
Onset of action is approximately 7 hours for symptom relief in seasonal allergic rhinitis, though maximum improvement may take 1-2 weeks 7, 2
Topical (Dermatological)
Mometasone furoate 0.1% lotion/cream/ointment is used for inflammatory skin conditions including eczema, psoriasis, and atopic dermatitis 3
The American Academy of Dermatology recommends intermittent dosing 2-3 times weekly for up to 36 weeks after initial clearance for chronic conditions like hand eczema and psoriasis 5
Inhaled (Pulmonary)
Mometasone furoate inhalation powder (Asmanex Twisthaler) delivers 100-200 μg per actuation for asthma management 2
The drug is a white powder with molecular formula C27H30Cl2O6 and molecular weight of 521.44 Daltons, insoluble in water but freely soluble in acetone and methylene chloride 3
Clinical Efficacy
Allergic Rhinitis
Mometasone furoate nasal spray is significantly more effective than placebo for controlling nasal congestion, rhinorrhea, sneezing, and nasal itching in both seasonal and perennial allergic rhinitis 8, 9, 10
Once-daily mometasone furoate is as effective as twice-daily beclomethasone dipropionate and comparable to once-daily fluticasone propionate for perennial allergic rhinitis 10, 7
The drug effectively relieves cough associated with seasonal allergic rhinitis, with significant improvement in daytime cough severity scores compared to placebo (P = 0.049) 8
Post-Viral Rhinosinusitis
Mometasone furoate 200 μg twice daily significantly reduces time to cure and major symptom scores in acute post-viral rhinosinusitis compared to placebo 1
Treatment is cost-effective, with reduced costs and increased quality-adjusted life years compared to amoxicillin or placebo 1
Nasal Polyps
Continuous daily use of 200 μg twice daily for up to 12 months postoperatively dramatically reduces polyp recurrence rates 5
Drug-eluting implants releasing mometasone over 90 days show efficacy and safety for nasal polyps treatment 5
Vascular Effects
- 15-day treatment with mometasone furoate significantly reduces vascular density in the nasal mucous membrane of allergic patients, with significant decreases in both blood capillaries (CD31 expression, p < 0.001) and lymph capillaries (VEGF-C expression) 1
Safety Profile
Mometasone furoate is well tolerated with an overall incidence of adverse events similar to placebo 7
Common side effects include nasal irritation/burning, headache, epistaxis (nosebleeds), pharyngitis, cough, and nasal irritation 6, 7
No detectable effect on hypothalamic-pituitary-adrenal axis function in studies up to 1 year duration 7
Growth studies in children show minimal impact: In a 52-week study of children 4-9 years with asthma, growth rate differences from placebo were not statistically significant for lower doses 2
Intranasal corticosteroids at recommended doses have not shown consistent clinically relevant effects on the hypothalamic-pituitary-adrenal axis or growth in children 6
Hepatic impairment increases mometasone concentrations, requiring monitoring in patients with severe liver disease 2
Important Clinical Considerations
Maximum symptom improvement requires 1-2 weeks or longer after starting treatment, so patients should be counseled about delayed onset of full therapeutic effect 2
When discontinued, asthma stability may persist for several days or longer, indicating sustained anti-inflammatory effects 2
Each patient should be titrated to the lowest effective dose to minimize systemic corticosteroid effects 2
Chronic overdosage may result in signs/symptoms of hypercorticism, though acute overdose is unlikely to require treatment beyond observation due to low systemic bioavailability 2