Intranasal Corticosteroids

Intranasal corticosteroids are the most effective single treatment for allergic rhinitis and are used for non-allergic rhinitis, nasal polyps, chronic rhinosinusitis and adenoid hypertrophy. They reduce blockage, sneezing, itch and discharge and also improve eye symptoms of allergy.

Mechanism. Activation of glucocorticoid receptors in the nasal mucosa reduces transcription of inflammatory cytokines, decreases mast cell, eosinophil and lymphocyte infiltration, reduces vascular permeability and suppresses late-phase allergic response.

Pharmacokinetics. Local effect with low systemic bioavailability: fluticasone and mometasone under 1 percent; budesonide about 30 percent; beclometasone about 40 percent (swallowed fraction metabolised by the liver). Onset is within 12 hours, with full effect after several days to 2 weeks of regular use.

• Fluticasone furoate 27.5 micrograms/spray: low bioavailability; once daily.
• Fluticasone propionate 50 micrograms/spray: once daily.
• Mometasone furoate 50 micrograms/spray: once daily.
• Budesonide 64 micrograms/spray: once or twice daily.
• Beclometasone dipropionate 50 micrograms/spray: twice daily; more systemic absorption.
• Triamcinolone acetonide 55 micrograms/spray; ciclesonide 50 micrograms/spray.
• Fixed combination: azelastine with fluticasone propionate, for inadequate response to a steroid alone.

Regimens.

• Adults and adolescents (allergic rhinitis): fluticasone furoate 2 sprays each nostril once daily (110 micrograms), then 1 spray once daily for maintenance; fluticasone propionate or mometasone 2 sprays each nostril once daily (200 micrograms daily); budesonide 2 sprays each nostril once daily or 1 spray twice daily; beclometasone 2 sprays each nostril twice daily.
• Nasal polyps: mometasone 2 sprays each nostril twice daily, or fluticasone propionate drops 400 micrograms (2 drops) each nostril once or twice daily with head-down technique; a course of at least 3 months, then maintenance.
• Children: mometasone 1 spray each nostril once daily from age 3 years (2 sprays from 12 years); fluticasone furoate 1 spray each nostril once daily from 2 years, increasing to 2 sprays; fluticasone propionate 1 spray each nostril once daily from 4 years, increasing to 2 sprays.
• Adenoid hypertrophy and otitis media with effusion adjunct: mometasone or fluticasone for 6 to 12 weeks.
• Technique: shake, tilt head forward, aim the nozzle towards the outer wall of each nostril away from the septum, sniff gently, and do not blow the nose for 15 minutes.

Selection. First-line for persistent or moderate to severe allergic rhinitis; start before the allergen season; use regularly rather than as needed. Combine with an oral or nasal antihistamine for breakthrough symptoms. Add saline irrigation for chronic rhinosinusitis. Refer if there is no response in 2 to 4 weeks or unilateral polyps.

Contraindications. Untreated nasal infection; recent nasal surgery, trauma or septal ulcers (wait until healed); hypersensitivity.

Effects. Epistaxis (up to 10 percent), nasal dryness, crusting and irritation, unpleasant taste, headache; septal perforation (rare, from poor technique); reduced growth velocity with prolonged beclometasone use in children (about 1 cm over a year); raised intraocular pressure, glaucoma and cataract (rare); oropharyngeal candidiasis (rare); adrenal suppression with high doses plus enzyme inhibitors.

Interactions. Ritonavir and cobicistat raise fluticasone and budesonide levels, causing Cushing syndrome and adrenal suppression; use beclometasone in people on boosted antiretroviral regimens. Strong CYP3A4 inhibitors (itraconazole, clarithromycin) also raise levels.

Monitoring. Review at 2 to 4 weeks for response; inspect the nose yearly in long-term use; measure height every 6 to 12 months in children on prolonged therapy; check eyes in glaucoma or cataract risk.

Special groups. Pregnancy: budesonide has the most data; others are acceptable when needed. Breastfeeding: acceptable. Children: lowest effective dose and growth monitoring. Region: allergic rhinitis frequently coexists with asthma and is under-treated; HIV treatment with ritonavir-boosted regimens is common, so check the antiretroviral regimen before choosing a steroid.