Arovent ODT

Approved Indications:

• Asthma (Maintenance Treatment):
  Long-term treatment and prophylaxis of asthma in adults and pediatric patients aged 12 months and older. Particularly effective in exercise-induced bronchospasm and aspirin-sensitive asthma.
• Seasonal Allergic Rhinitis (SAR):
  Relief of nasal and non-nasal symptoms in adults and children aged 2 years and older.
• Perennial Allergic Rhinitis (PAR):
  Treatment of year-round allergic rhinitis in adults and children aged 6 months and older.
• Exercise-Induced Bronchoconstriction (EIB):
  Prevention of bronchospasm caused by physical exertion in patients aged 6 years and older.

Off-label (Clinically Accepted) Uses:

• Chronic urticaria (hives):
  Used as adjunct therapy in antihistamine-refractory cases.
• Atopic dermatitis in combination with other therapies.
• Allergic rhinosinusitis with nasal polyps in selected patients.

Adults and Adolescents (≥15 years):

• Asthma: 10 mg once daily in the evening.
• Allergic Rhinitis (Seasonal or Perennial): 10 mg once daily, at any time of day.
• Exercise-Induced Bronchoconstriction: 10 mg at least 2 hours before exercise; do not take an additional dose within 24 hours.

Pediatric Population:

• Children 6–14 years: 5 mg chewable tablet once daily in the evening.
• Children 2–5 years: 4 mg chewable tablet once daily in the evening.
• Children 6–23 months: 4 mg oral granules once daily in the evening.
• Infants <6 months: Not recommended due to lack of safety data.

Special Populations:

• Elderly: No dosage adjustment required.
• Renal Impairment: No dosage adjustment needed.
• Hepatic Impairment: Use with caution in mild-to-moderate hepatic impairment; avoid in severe hepatic impairment.

Administration Route:

• Oral: Administer tablets, chewables, or oral granules as indicated. Granules can be taken directly or mixed with soft food (not liquid), used within 15 minutes of opening.

Montelukast Sodium is a selective leukotriene receptor antagonist that blocks the action of cysteinyl leukotrienes (LTC4, LTD4, and LTE4) at the CysLT1 receptor found in airway smooth muscle and other pro-inflammatory cells. These leukotrienes are involved in the pathophysiology of asthma and allergic rhinitis, leading to bronchoconstriction, increased vascular permeability, mucus secretion, and eosinophil recruitment. By inhibiting these actions, montelukast helps reduce inflammation, airway edema, and bronchospasm, thereby improving respiratory symptoms and reducing the frequency of asthma exacerbations.

• Absorption: Rapidly absorbed after oral administration.
• Bioavailability: ~64% (10 mg tablet); unaffected by food.
• Tmax: 2–4 hours (10 mg tablet); 2 hours (4 mg granules).
• Distribution:
• Volume of distribution: ~8–11 L.
• Protein binding: >99% to plasma proteins.
• Metabolism:
  Extensively metabolized by liver enzymes, primarily CYP3A4 and CYP2C9. Major metabolites are inactive.
• Excretion:
• Elimination half-life: 2.7 to 5.5 hours.
• Excreted primarily via bile; minimal renal excretion (<0.2%).
• Steady-State: Achieved in about 3 days with once-daily dosing.

• Pregnancy:
  Montelukast is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal harm, but well-controlled studies in pregnant women are lacking. Should be used during pregnancy only if clearly needed.
• Lactation:
  Montelukast is excreted in human breast milk in small amounts. Consider the benefit of treatment against the potential risk to the infant. No adverse effects reported in breastfed infants.
• Caution:
  If treatment is necessary in pregnancy or lactation, use the lowest effective dose and monitor both mother and child.

• Primary Class: Leukotriene Receptor Antagonist (LTRA)
• Subclass: CysLT1 Receptor Blocker
• Generation: Non-steroidal anti-inflammatory agent for respiratory conditions

• Hypersensitivity to Montelukast Sodium or any component of the formulation.
• Severe hepatic impairment (Child-Pugh score >9).
• Acute asthma attacks or status asthmaticus (not effective for rescue treatment).

• Neuropsychiatric Events:
  Reports of agitation, aggression, anxiety, depression, hallucinations, sleep disturbances, and suicidal thoughts. Discontinue if behavioral changes occur.
• Churg-Strauss Syndrome:
  Rare cases of systemic eosinophilia and vasculitis reported, particularly with corticosteroid tapering.
• Not a Rescue Medication:
  Should not be used to treat acute bronchospasm.
• Phenylketonuria:
  Chewable tablets contain phenylalanine – use caution in PKU patients.
• Monitor Liver Function:
  Especially in patients with pre-existing hepatic disease.

Common Side Effects (≥1%):

• CNS: Headache, dizziness, fatigue
• GI: Abdominal pain, nausea, diarrhea
• Respiratory: Upper respiratory tract infections, cough, nasal congestion
• Dermatologic: Rash

Less Common/Serious:

• Neuropsychiatric: Depression, suicidal ideation, sleepwalking, tremor, hallucinations
• Hepatic: Elevated liver enzymes, hepatotoxicity (rare)
• Hypersensitivity: Angioedema, urticaria, anaphylaxis

Timing:
Most adverse effects occur within days to weeks of initiation; neuropsychiatric events may occur at any time.

• CYP450 Interactions:
• Inducers (e.g., rifampin, phenobarbital) may reduce montelukast levels.
• Inhibitors of CYP3A4/2C9 may increase plasma concentration (not typically clinically significant).
• Phenytoin: May reduce montelukast effectiveness.
• Food Interactions:
  Food delays Tmax but does not significantly affect total absorption.
• Alcohol: No known direct interaction, but caution advised in patients with liver dysfunction.

• 2020–2022 FDA Boxed Warning:
  Added warning regarding serious neuropsychiatric adverse effects, including suicidal ideation. Providers are advised to weigh benefits and risks, especially for allergic rhinitis.
• Global Guidelines:
  Montelukast is no longer first-line for allergic rhinitis unless antihistamines are not tolerated or ineffective.
• Updated Pediatric Recommendations:
  Use in children primarily for mild persistent asthma unresponsive to inhaled corticosteroids or where ICS cannot be used.

• Temperature: Store below 30°C (86°F); do not refrigerate.
• Humidity/Light: Protect from moisture and light; keep tablets in the original blister pack until use.
• Granules: Use within 15 minutes of opening; do not store mixed granules.
• Handling: Keep out of reach of children. Do not use if tablets are discolored or damaged.