NASONEX 24HR ALLERGY
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NASONEX 24HR ALLERGY (NASONEX 24HR ALLERGY).
Glucocorticoid receptor agonist; inhibits inflammatory mediators including cytokines, chemokines, and adhesion molecules; reduces nasal inflammation.
| Metabolism | Minimal hepatic metabolism via CYP3A4; extensive first-pass metabolism; primarily excreted as metabolites in bile and urine. |
| Excretion | Mometasone furoate is predominantly eliminated via biliary/fecal excretion. After intravenous administration, approximately 74% of the dose is recovered in feces and about 8% in urine. The drug undergoes extensive hepatic metabolism, and metabolites are excreted primarily in bile. |
| Half-life | The terminal elimination half-life of mometasone furoate is approximately 5.8 hours. This short half-life supports once-daily dosing for intranasal use, but systemic accumulation is minimal with topical administration. |
| Protein binding | Mometasone furoate is approximately 98-99% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | The volume of distribution (Vd) at steady state is approximately 332 L (about 4.7 L/kg assuming a 70 kg individual). This large Vd indicates extensive tissue distribution and binding to extravascular sites. |
| Bioavailability | Intranasal: The absolute bioavailability of intranasal mometasone furoate is approximately <1% due to extensive first-pass metabolism and low systemic absorption. When administered orally, bioavailability is also negligible (<1%) due to first-pass metabolism. |
| Onset of Action | Intranasal: Onset of action for relief of allergic rhinitis symptoms (e.g., nasal congestion, rhinorrhea) is typically within 12 hours after the first dose, with maximum benefit observed after 1-2 weeks of regular use. |
| Duration of Action | Intranasal: The duration of action supports once-daily dosing. Symptom relief persists for 24 hours after a single dose, but continuous daily use is recommended for optimal control of allergic rhinitis. |
| Molecular Weight | 521.44 |
2 sprays (50 mcg/spray) per nostril once daily; total dose 200 mcg/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 2-11 years: 1 spray (50 mcg) per nostril once daily; total dose 100 mcg/day. |
| Geriatric use | No specific dose adjustment; use standard adult dosing. |
| 1st trimester | No adequate studies in pregnant women; use only if potential benefit justifies risk. Intranasal corticosteroids generally considered low risk. |
| 2nd trimester | No evidence of harm in animal studies; limited human data. Use if clearly needed. |
| 3rd trimester | No known risk of fetal harm; monitor for potential adrenal suppression in neonate with high doses. |
Clinical note
Comprehensive clinical and safety monograph for NASONEX 24HR ALLERGY (NASONEX 24HR ALLERGY).
| Placental transfer | Mometasone furoate crosses the placenta in animal studies; human data limited but systemic absorption after intranasal administration is <0.1%. |
| Breastfeeding | Mometasone furoate is excreted in breast milk in small amounts; however, intranasal use results in negligible systemic exposure. Considered compatible with breastfeeding. |
■ FDA Black Box Warning
No FDA boxed warning.
| Serious Effects |
Hypersensitivity to mometasone furoate or any component of the formulationUntreated nasal mucosal infection (e.g., herpes simplex)
| Precautions | Nasal fungal infections; monitor for Candida albicans, Potential for glaucoma and cataracts with long-term use, Risk of adrenal suppression with excessive doses or systemic absorption, May delay wound healing after nasal surgery or trauma, Avoid use in patients with active tuberculosis or untreated infections |
| Food/Dietary | No significant food interactions. Avoid grapefruit products if on concurrent medications that interact with CYP3A4 (e.g., some statins, calcium channel blockers), but mometasone furoate has negligible oral bioavailability and systemic interaction risk is low. |
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| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Mometasone furoate (NASONEX 24HR ALLERGY) is an intranasal corticosteroid. Systemic absorption is minimal at recommended doses. Animal studies with high doses showed some teratogenic effects (cleft palate), but human data are limited. First trimester: No well-controlled studies, but low systemic exposure suggests minimal risk. Second and third trimesters: No known fetal risks, but use only if clearly needed. |
| Fetal Monitoring | No specific maternal-fetal monitoring required. Monitor for signs of adrenal suppression if used chronically at high doses, though unlikely with nasal administration. |
| Fertility Effects | No known effect on fertility at recommended doses. Animal studies showed no impairment of fertility. |
| Clinical Pearls | Nasal corticosteroids like mometasone furoate are first-line for allergic rhinitis; onset of action is 12 hours but maximal benefit may take 1-2 weeks. Priming the pump (6-10 sprays or until fine mist appears) is necessary for new or unused devices. Tilt head forward slightly and spray away from septum to reduce risk of epistaxis. No systemic adrenal suppression at recommended doses. May be used in pregnancy if benefit outweighs risk (Category C). |
| Patient Advice | Shake the bottle gently before each use. · Prime the spray by pumping 6-10 times into air until a fine mist appears; if not used for 1 week or more, reprime with 2 sprays. · Blow nose gently to clear nasal passages before application. · Close one nostril and insert tip into the other; tilt head slightly forward and aim spray away from the nasal septum. · Spray while breathing in gently through the nose; do not sniff hard. · Avoid spraying directly onto the nasal septum to prevent nosebleeds. · Do not use more than 2 sprays per nostril per day (each spray = 50 mcg, total 200 mcg/day). · Clean the nosepiece weekly with a damp cloth; do not immerse in water. · Do not share the medication with others. · Common side effects include mild nosebleeds, headache, sore throat, or cough; report persistent nosebleeds or nasal discomfort. |