Provair (Montelukast): A Leukotriene Receptor Antagonist

Provair contains Montelukast, which is a selective and orally active leukotriene receptor antagonist. It is indicated for the prophylaxis and chronic treatment of asthma, acute prevention of Exercise-Induced Bronchoconstriction (EIB), and the relief of symptoms of Allergic Rhinitis (Seasonal & Perennial). It belongs to the therapeutic class of Leukotriene receptor antagonists.

How Provair Works (Pharmacology)

Montelukast works by:

• Inhibiting Cysteinyl Leukotriene Receptor (CysLT1): It specifically blocks the CysLT1 receptor.
• Blocking Effects of Cysteinyl Leukotrienes: Cysteinyl leukotrienes (LTC4, LTD4, LTE4) are inflammatory mediators released from cells like mast cells and eosinophils. These leukotrienes contribute to the pathophysiology of asthma and allergic rhinitis by causing airway edema, smooth muscle contraction, and altered cellular activity associated with inflammation.
• Reducing Asthma & Allergic Rhinitis Symptoms: By inhibiting the effects of these leukotrienes, Montelukast helps to reduce inflammation, airway narrowing, and other signs and symptoms of asthma and allergic rhinitis.

Key Indications & Benefits

Provair is indicated for:

• Prophylaxis and chronic treatment of asthma.
• Acute prevention of Exercise-Induced Bronchoconstriction (EIB).
• Relief of symptoms of Allergic Rhinitis (AR): Both Seasonal & Perennial Allergic Rhinitis.

Dosage & Administration

Provair is taken orally once daily. Always consult a registered physician for medication use.

• Adults and adolescents 15 years of age and older: Montelukast 10 mg tablet once daily.
• Pediatric patients 6 to 14 years of age: Montelukast 5 mg tablet once daily.
• Pediatric patients 2 years to 5 years of age: Montelukast 4 mg tablet once daily.
• Pediatric patients 6 months to 5 years of age: Montelukast 4 mg oral granules once daily. Can be administered directly in the mouth, or mixed with a spoonful of cold water or soft food at room temperature.

Special Populations:

• Pediatric Patients: Safety and efficacy established in adequate studies for asthma in pediatric patients 6 months to 14 years of age, with similar profiles to adults.
• Hepatic Insufficiency: No dosage adjustment is required in patients with mild-to-moderate hepatic insufficiency.
• Renal Insufficiency: No dosage adjustment is recommended.
• Elderly Use: No dosage adjustment is required. The pharmacokinetic profile and bioavailability are similar, though the plasma half-life is slightly longer.

Important Considerations & Warnings

It is crucial to discuss your full medical history with your doctor before taking Provair.

Contraindications:

• Patients who are hypersensitive to any component of this product.

Side Effects:

• Common: Diarrhea, fever, gastrointestinal discomfort, headache, nausea, vomiting, skin reactions, upper respiratory tract infection.
• Uncommon: Akathisia, anxiety, arthralgia, asthenia, abnormal behavior, depression, dizziness, drowsiness, dry mouth, hemorrhage, irritability, malaise, muscle complaints, edema, seizure, abnormal sensation, sleep disorders.
• Rare: Angioedema, impaired concentration, disorientation, eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome), erythema nodosum, hallucination, hepatic disorders, memory loss, palpitations, pulmonary eosinophilia, suicidal tendencies, tremor.

Pregnancy & Lactation:

• Pregnancy: Montelukast crosses the placenta in animal studies. However, there are no adequate and well-controlled studies in pregnant women. It should be used during pregnancy only if clearly needed, as animal studies are not always predictive of human response.
• Lactation: It is unknown whether Montelukast is excreted in human milk. Caution should be exercised when given to a nursing mother due to the potential for drug excretion in human milk.

Precautions & Warnings:

• Not for Acute Asthma Attacks: Provair is not indicated for use in the reversal of bronchospasm in acute asthma attacks, including status asthmaticus. Patients should always have appropriate rescue medication available.
• Acute Exacerbations: Therapy with Provair can be continued during acute exacerbations of asthma.
• Not an Abrupt Substitute for Corticosteroids: Provair should not be abruptly substituted for inhaled or oral corticosteroids. The dose of inhaled corticosteroid may be reduced gradually under medical supervision.
• Not Monotherapy for EIB: Provair should not be used as monotherapy for the treatment and management of exercise-induced bronchoconstriction.
• Aspirin Sensitivity: Patients with known aspirin sensitivity should continue avoidance of aspirin or non-steroidal anti-inflammatory agents while taking Provair. While effective in improving airway function in asthmatics with documented aspirin sensitivity, it has not been shown to truncate bronchoconstrictor response to aspirin and other NSAIDs in these patients.

Drug Interactions:

• Generally, no clinically important interactions. Provair has been administered with common asthma therapies (e.g., theophylline, prednisone, oral contraceptives, terfenadine, digoxin, warfarin) without apparent increase in adverse reactions.
• Potent Cytochrome P450 Enzyme Inducers (e.g., Phenobarbital, Rifampin): Phenobarbital decreased the AUC of Provair by approximately 40%. No dosage adjustment for Provair is recommended, but appropriate clinical monitoring is reasonable when these inducers are co-administered.
• Used concomitantly with a wide range of commonly prescribed drugs (thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants) in clinical studies without evidence of clinical adverse interactions.

Overdose Effects

• In most overdosage reports, there were no adverse experiences.
• Most frequently occurring adverse experiences (consistent with safety profile): Abdominal pain, somnolence, thirst, headache, vomiting, and psychomotor hyperactivity.
• Management: In the event of overdose, employ usual supportive measures, such as removing unabsorbed material from the gastrointestinal tract, clinical monitoring, and supportive therapy if required.

Storage Conditions

Store in a cool and dry place below 30°C. Protect from light and moisture. Keep out of reach of children.