NASAREL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NASAREL (NASAREL).
Corticosteroid that binds to glucocorticoid receptors, inhibiting inflammatory mediators such as prostaglandins, leukotrienes, and cytokines, thereby reducing nasal inflammation.
| Metabolism | Primarily hepatic via CYP3A4 isoform; undergoes extensive first-pass metabolism. |
| Excretion | Primarily hepatic metabolism; renal excretion of metabolites accounts for <30% of dose. Fecal elimination minimal (<5%). |
| Half-life | Terminal half-life approximately 15-25 minutes for flunisolide (the active ingredient in NASAREL) in the systemic circulation after intranasal administration. Clinically, the half-life is short, reducing the risk of systemic accumulation but requiring twice-daily dosing for consistent effect. |
| Protein binding | Approximately 40-50% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution is approximately 1.4–2.0 L/kg after IV administration, indicating extensive tissue distribution. For intranasal use, the Vd is not directly applicable but reflects systemic exposure if absorbed. |
| Bioavailability | Intranasal: Systemic bioavailability is approximately 21% (range 10-50%) due to first-pass metabolism. Oral bioavailability is <1% due to extensive hepatic first-pass effect. The drug is administered intranasally for local effect with low systemic exposure. |
| Onset of Action | Intranasal: Symptom relief begins within 12-24 hours, with full therapeutic effect achieved after several days of regular use. |
| Duration of Action | Duration of clinical effect is approximately 12-24 hours, supporting twice-daily dosing (e.g., 2 sprays each nostril BID). Maximal benefit may take up to 2 weeks. |
| Molecular Weight | 500.57 |
2 sprays (50 mcg/spray) in each nostril once or twice daily; maximum 8 sprays/day.
| Dosage form | SPRAY, METERED |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | Children 6-11 years: 1 spray in each nostril once daily; maximum 4 sprays/day. Children ≥12 years: same as adult. |
| Geriatric use | No specific dose adjustment; use lowest effective dose. |
| 1st trimester | Avoid use due to potential teratogenic effects; limited human data, but animal studies show congenital anomalies. |
| 2nd trimester | Use only if clearly needed and benefit outweighs risk; maternal adrenal suppression possible. |
| 3rd trimester | Use only if clearly needed; risk of neonatal adrenal suppression if used near term. |
Clinical note
Comprehensive clinical and safety monograph for NASAREL (NASAREL).
| Placental transfer | Fluticasone propionate crosses the placenta; feto-maternal ratio approximately 0.2. |
| Breastfeeding | Excretion into human milk is unknown; however, systemic absorption is minimal. Caution in mothers breastfeeding preterm infants or those with adrenal suppression. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to fluticasone propionateUntreated nasal mucosal infections (bacterial, fungal, viral)Recent nasal surgery or trauma until healing is complete
| Precautions | May cause epistaxis, nasal septal perforation, or nasal mucosal ulceration, Potential for systemic corticosteroid effects with prolonged use, May suppress hypothalamic-pituitary-adrenal (HPA) axis, especially at higher doses, Increased susceptibility to infections; avoid in active untreated infections, Use with caution in patients with tuberculosis, ocular herpes simplex, or untreated fungal/bacterial infections |
| Food/Dietary | No significant food interactions known. May take without regard to meals. Avoid consuming grapefruit or grapefruit juice as it may increase systemic exposure (weak CYP3A4 interaction). |
Loading safety data…
| L3 - Moderately Safe |
| Teratogenic Risk | FDA Pregnancy Category C: In animal studies, corticosteroids have been shown to be teratogenic at high doses. No adequate and well-controlled studies in pregnant women. Nasarel (flunisolide) should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. First trimester: Theoretical risk of cleft palate; avoid systemic absorption by using minimal effective dose. Second and third trimesters: No specific risks reported; monitor for fetal adrenal suppression if used chronically at high doses. |
| Fetal Monitoring | Monitor maternal adrenal function if using high doses or long-term therapy. Assess fetal growth via ultrasound if used throughout pregnancy. Monitor infant for adrenal suppression postnatally if maternal use was prolonged. |
| Fertility Effects | No specific studies on fertility in humans. In animal studies, corticosteroids may impair fertility at high doses. Theoretical risk of reversible menstrual irregularities with systemic absorption; intranasal route minimizes systemic exposure. |
| Clinical Pearls | For best results, advise patients to blow nose gently before use. Avoid spraying directly onto nasal septum to reduce risk of epistaxis and septal perforation. Tilt head forward slightly and spray away from septum. Priming pump (6 sprays or until fine mist appears) is essential if not used for >7 days. Monitor nasal mucosal integrity during long-term use. May cause transient stinging or burning; consider co-administration with saline spray if irritation persists. |
| Patient Advice | Use exactly as prescribed; do not exceed recommended dose. · Shake bottle gently before each use. · Prime pump by spraying 6 times into air if new or not used for 7 or more days. · Blow nose to clear nasal passages before administration. · Insert nozzle into nostril, tilt head slightly forward, and spray away from the nasal septum. · Avoid spraying directly onto the nasal septum. · Rinse nozzle with warm water after each use and replace cap tightly. · Do not share the medication with others. · If using other nasal sprays, use them at different times (separated by 10-15 minutes). · Contact doctor if symptoms do not improve after 3 weeks or if nasal bleeding occurs. |