Mometasone Inhaled

Mometasone is a potent inhaled corticosteroid with very low oral bioavailability, given once or twice daily for asthma and available in combination with formoterol.

Classification. Inhaled corticosteroid, glucocorticoid.

Mechanism. High-affinity glucocorticoid receptor agonist suppressing airway inflammation.

Pharmacokinetics. Oral bioavailability under 1%. Extensive hepatic metabolism by CYP3A4. Faecal elimination.

First-line, persistent asthma, adults and adolescents from 12 years. Dry powder 200 to 400 micrograms once daily in the evening. Higher doses of 400 micrograms twice daily under specialist direction. Maximum 800 micrograms daily. The strength labelled on products differs between regions.

Combination with formoterol. Mometasone with formoterol 100/5 or 200/5 micrograms, 2 puffs twice daily, where licensed.

Children. Licensing differs by region (from 4 or 5 years in some). Where licensed, 100 micrograms once daily in the evening; higher doses only under specialist direction.

Alternative. Another ICS, particularly beclometasone with ritonavir-boosted regimens.

Emergency. Not used.

Titration. Reduce to the lowest effective dose after 3 months of control. No loading dose.

Contraindications. Hypersensitivity, including severe milk protein allergy for powder products. Caution in active or quiescent tuberculosis.

Serious adverse effects. Adrenal suppression, reduced growth velocity, cataract, glaucoma, osteoporosis, paradoxical bronchospasm.

Common adverse effects. Headache, oropharyngeal candidiasis, dysphonia, pharyngitis.

Interactions. Strong CYP3A4 inhibitors including ritonavir, cobicistat, ketoconazole and clarithromycin raise exposure; avoid unless the benefit outweighs the risk.

Common prescribing errors. Twice daily dosing for a once daily product. Confusing strengths between regions.

Special groups.

• Pregnancy: use if benefit outweighs risk. Breastfeeding: no data; likely small amounts.

• Children: measure height at least annually.

• Older adults: no adjustment.

• Kidney impairment: no adjustment. Liver impairment: exposure increases in severe disease; monitor.

Formulations. Dry powder device and inhaler; fixed combinations.

Technique. Rinse the mouth after use. Inhale quickly and deeply from dry powder devices.

Baseline. Spirometry or peak flow, control score.

Monitoring. Symptoms, exacerbations, spirometry, technique, height in children.

Stop and reduce rules. Step down when control holds. Therapeutic drug monitoring is not used.

Referral and escalation. Refer if control fails on high dose with a LABA.