NASONEX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NASONEX (NASONEX).
Corticosteroid with anti-inflammatory activity; binds to glucocorticoid receptors, inhibiting inflammatory mediators like prostaglandins and leukotrienes.
| Metabolism | Hepatic metabolism via CYP3A4; desonide undergoes extensive biotransformation. |
| Excretion | Mometasone furoate is extensively metabolized in the liver, primarily via CYP3A4, and metabolites are excreted mostly in feces (approximately 74%) and to a lesser extent in urine (approximately 8%). |
| Half-life | The terminal elimination half-life of mometasone furoate following intranasal administration is approximately 5.8 hours (range 2.7–11.5 hours) in adults, reflecting rapid clearance from systemic circulation. |
| Protein binding | Mometasone furoate is approximately 98-99% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | The volume of distribution at steady state (Vss) is 332 L (approximately 4.5 L/kg for a 70 kg adult), indicating extensive tissue distribution. |
| Bioavailability | Intranasal bioavailability is less than 1% due to low systemic absorption; oral bioavailability is negligible (less than 1% due to extensive first-pass metabolism). |
| Onset of Action | Improvement in nasal symptoms is observed within 12 hours after the first intranasal dose in seasonal allergic rhinitis; however, maximal benefit may require several days. |
| Duration of Action | The duration of action supports once-daily dosing, with sustained relief over 24 hours in seasonal and perennial allergic rhinitis. No significant accumulation occurs with repeated dosing. |
Mometasone furoate 200 mcg per day as 2 sprays (50 mcg/spray) in each nostril once daily. May reduce to 100 mcg per day (1 spray per nostril once daily) if symptoms controlled. Maximum 200 mcg per day.
| Dosage form | SPRAY, METERED |
| Renal impairment | No dose adjustment required for renal impairment. No GFR-based guidelines exist. |
| Liver impairment | No specific dose adjustment recommended for hepatic impairment. No Child-Pugh based modifications established. |
| Pediatric use | Ages 2–11 years: 1 spray (50 mcg) per nostril once daily (100 mcg total). Ages 12–17 years: same as adult (2 sprays per nostril once daily, 200 mcg total). |
| Geriatric use | No specific dose adjustment required. Use same as adult dosing. Monitor for local adverse effects (e.g., epistaxis, nasal irritation) which may be more common in elderly. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NASONEX (NASONEX).
| Breastfeeding | It is not known whether mometasone furoate is excreted in human milk. Because many corticosteroids are excreted in human milk, caution should be exercised when Nasonex is administered to a nursing woman. M/P ratio: Not available. |
| Teratogenic Risk | FDA Pregnancy Category C. In animal studies, corticosteroids have been shown to be teratogenic. There are no adequate and well-controlled studies in pregnant women. Nasonex (mometasone furoate) should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. First trimester: Limited data, risk cannot be ruled out. Second trimester: Use with caution if benefit outweighs risk. Third trimester: Potential for fetal adrenal suppression with prolonged use. |
■ FDA Black Box Warning
None.
| Common Effects | Nasal discomfort |
| Serious Effects |
["Hypersensitivity to any component","Untreated nasal infection (e.g., herpes simplex)","Recent nasal surgery or trauma (until healing completed)"]
| Precautions | ["Nasal corticosteroid withdrawal symptoms upon discontinuation","Risk of adrenal suppression with high doses or prolonged use","Increased susceptibility to fungal infections (e.g., Candida albicans)","Potential for growth retardation in children","Hoarseness, epistaxis, and nasal septal perforation with misuse"] |
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| Fetal Monitoring | No specific monitoring required beyond standard prenatal care. Monitor for signs of adrenal suppression in the neonate if used chronically during pregnancy. |
| Fertility Effects | No specific studies on fertility in humans. Animal studies have not shown impairment of fertility at doses up to 56 mcg/kg/day (approximately 2 times the maximum human daily intranasal dose on a mcg/m² basis). |