Systemic Absorption of Fluticasone Furoate from Avamys Nasal Spray
When using Avamys (fluticasone furoate) nasal spray at the standard adult dose of 2 sprays per nostril once daily (110 mcg total daily dose) for one month, the total amount of systemically absorbed steroid is negligible—the majority of patients will have unquantifiable plasma levels of fluticasone furoate. 1
Understanding Systemic Absorption
Fluticasone furoate is specifically engineered for minimal systemic exposure, with enhanced affinity for the glucocorticoid receptor that allows therapeutic efficacy while maintaining extremely low bioavailability. 2
In a 12-week pediatric study using the same formulation, the majority of patients receiving fluticasone furoate 55 mcg once daily had unquantifiable plasma levels, demonstrating that even with chronic use, systemic absorption remains below detection thresholds in most individuals. 1
The drug exhibits low systemic exposure by design, which is a key safety feature distinguishing it from older intranasal corticosteroids. 2
Calculating Total Exposure Over One Month
Standard adult dosing is 110 mcg total per day (2 sprays per nostril, with each spray delivering 27.5 mcg of fluticasone furoate). 2, 3
Over 30 days, the total administered dose would be 3,300 mcg (3.3 mg), but this represents the amount delivered to the nasal mucosa, not the amount absorbed systemically.
Because systemic bioavailability is extremely low and plasma levels are typically unquantifiable, calculating a precise "absorbed amount" is not clinically meaningful—the absorbed fraction is negligible compared to the administered dose. 1
Clinical Implications of Low Systemic Absorption
No clinically significant suppression of the hypothalamic-pituitary-adrenal axis occurs at recommended doses in children or adults, even with long-term use. 4
No adverse effects on growth have been documented in pediatric patients using fluticasone furoate at recommended doses, unlike some older intranasal corticosteroids. 4
No increased risk of ocular complications (cataracts, glaucoma, elevated intraocular pressure) has been associated with prolonged use. 4
Long-term safety data extending up to 52 weeks demonstrate no difference in safety profile between short-term and extended use, confirming that systemic accumulation does not occur. 4
Important Safety Considerations
The most common adverse events are local rather than systemic: epistaxis (nasal bleeding), headache, and nasopharyngitis are mild and occur at rates similar to placebo. 2, 1
Proper administration technique minimizes even local side effects: directing the spray away from the nasal septum using the contralateral hand reduces epistaxis risk by four times. 4
Systemic side effects typical of oral corticosteroids—such as adrenal suppression, bone density loss, or metabolic effects—do not occur with intranasal fluticasone furoate at therapeutic doses. 4