Long-Term Safety of Flunisolide 25 mcg Daily Nasal Spray
Yes, flunisolide 25 mcg daily nasal spray is safe for long-term use in adults, with evidence supporting continuous therapy for up to 2 years without serious adverse effects or adrenal suppression. 1
Evidence for Long-Term Safety
The FDA label and clinical research directly address the safety profile of flunisolide at the 25 mcg per spray dose:
A 24-month follow-up study of flunisolide nasal spray (at 300 mcg/day or less) demonstrated no serious side effects or evidence of adrenal suppression, with 10 patients continuing to obtain subjective benefit after 2 years of continuous therapy. 1
ACTH stimulation testing performed on six patients after 1 year of flunisolide therapy at 300 mcg/day or less showed no adrenal suppression. 1
Morning plasma cortisol concentrations measured before and after 1 month and 3 months of flunisolide therapy revealed no significant diminution in cortisol levels compared to placebo-treated patients. 2
Systemic Safety Profile
Flunisolide at recommended doses has minimal systemic effects:
At conventional doses (25 mcg per spray, typically 2 sprays per nostril 2-3 times daily = 200-300 mcg/day), there is no important risk to endogenous adrenal function, even when combined with other corticosteroids by other routes. 3
The FDA label states that although systemic effects are minimal at recommended doses, excessive doses may suppress HPA function, so larger than recommended doses should be avoided. 4
Intranasal corticosteroids as a class, including flunisolide, show no suppression of the hypothalamic-pituitary-adrenal axis at recommended doses in children or adults. 5
Local Side Effects and Monitoring
The most common adverse effects are local and manageable:
Local infections of the nose and pharynx with Candida albicans have occurred only rarely in clinical studies with intranasal flunisolide; when such infection develops, it may require treatment with appropriate local therapy or discontinuance. 4
Common side effects of intranasal corticosteroids include nasal irritation, epistaxis (nose bleeds), and pharyngitis, which are rare and can be avoided with proper administration technique. 5
No long-term adverse local or systemic steroid effects attributable to flunisolide were observed in clinical trials. 2
Important Caveats and Contraindications
Several clinical situations require caution:
The FDA label advises that flunisolide should be used with caution in patients with active or quiescent tuberculosis infection of the respiratory tract, untreated fungal, bacterial or systemic viral infections, or ocular herpes simplex. 4
In patients who have experienced recent nasal septal ulcers, recurrent epistaxis, nasal surgery or trauma, flunisolide should be used with caution until healing has occurred due to the inhibitory effect of corticosteroids on wound healing. 4
The FDA label states that if symptoms do not improve within 3 weeks, flunisolide should not be continued beyond this period in the absence of significant symptomatic improvement. 4
Pediatric Considerations
For children, additional monitoring is warranted:
Flunisolide nasal solution is not recommended for use in pediatric patients less than 6 years of age as safety and efficacy have not been assessed in this age group. 4
The FDA label mandates that the growth of pediatric patients receiving intranasal corticosteroids, including flunisolide, should be monitored routinely (e.g., via stadiometry), as controlled clinical studies have shown that intranasal corticosteroids may cause a reduction in growth velocity. 4
Growth velocity is a more sensitive indicator of systemic corticosteroid exposure in pediatric patients than some commonly used tests of HPA axis function. 4
Practical Recommendations for Long-Term Use
To maximize safety during extended therapy:
Patients should use flunisolide at regular intervals since its effectiveness depends on regular use; one to two weeks may pass before full relief is obtained. 4
Patients should clear their nasal passages of secretions prior to use and follow proper administration technique to minimize local side effects. 4
Periodic nasal examination should be performed during long-term use to detect any mucosal erosions or local complications. 5
The lowest effective dose should be used for maintenance therapy once symptom control is achieved. 5