Reversair (Montelukast): A Leukotriene Receptor Antagonist

Reversair contains Montelukast, 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 relief of symptoms of allergic rhinitis (seasonal and perennial). It belongs to the therapeutic class of Leukotriene receptor antagonists. 

How Reversair Works (Pharmacology)

Montelukast works by: 

• Inhibiting Cysteinyl Leukotriene Receptors (CysLT1): Montelukast selectively blocks the CysLT1 receptor. 
• Targeting Inflammatory Mediators: Cysteinyl leukotrienes (LTC4, LTD4, LTE4) are inflammatory chemicals produced from arachidonic acid metabolism and released by cells like mast cells and eosinophils. These leukotrienes play a key role in the pathophysiology of asthma and allergic rhinitis by causing airway edema, smooth muscle contraction, and altered cellular activity associated with inflammation. 
• Reducing Symptoms: By inhibiting the effects of these leukotrienes, Montelukast reduces airway inflammation, bronchoconstriction, and other symptoms associated with asthma and allergic rhinitis. 

Key Indications & Benefits

Reversair 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 and Perennial Allergic Rhinitis. 

Dosage & Administration

Reversair is taken once daily. Dosage varies by age. Always consult a registered physician for specific dosage instructions. 

• Adults and adolescents (15 years of age and older) with asthma or seasonal allergic rhinitis: Montelukast 10 mg tablet once daily. 
• Pediatric patients (6 to 14 years of age) with asthma or seasonal allergic rhinitis: 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 given directly or mixed with a spoonful of cold water or soft food at room temperature. 

Special Populations:

• Hepatic Insufficiency (mild-to-moderate): No dosage adjustment is required. 
• Renal Insufficiency: No dosage adjustment is recommended. 
• Elderly use: No dosage adjustment is required. The pharmacokinetic profile is similar to younger adults, though plasma half-life is slightly longer in the elderly. 

Important Considerations & Warnings

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

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 (joint pain), asthenia (weakness), abnormal behavior, depression, dizziness, drowsiness, dry mouth, hemorrhage, irritability, malaise, muscle complaints, edema, seizure, abnormal sensation, sleep disorders. 
• Rare: Angioedema (swelling), impaired concentration, disorientation, eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome, a rare inflammatory condition), erythema nodosum, hallucination, hepatic disorders, memory loss, palpitations, pulmonary eosinophilia, suicidal tendencies, tremor. 

Pregnancy & Lactation:

• Pregnancy: There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if clearly needed, as animal studies are not always predictive of human response. 
• Lactation: Caution should be exercised when Montelukast is given to a nursing mother, as many drugs are excreted in human milk. 

Precautions & Warnings:

• Acute Asthma Attacks: Reversair 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 Reversair can be continued during acute exacerbations of asthma. 
• Corticosteroid Substitution: Reversair should not be abruptly substituted for inhaled or oral corticosteroids. Doses of inhaled corticosteroids should be reduced gradually under medical supervision. 
• Exercise-Induced Bronchospasm: Reversair should not be used as monotherapy for the treatment and management of exercise-induced bronchospasm. 
• Aspirin Sensitivity: Patients with known aspirin sensitivity should continue avoidance of aspirin or non-steroidal anti-inflammatory agents while taking Reversair. Although it can improve airway function in asthmatics with documented aspirin sensitivity, it has not been shown to prevent bronchoconstrictor responses to aspirin and other NSAIDs in these patients. 
• Psychiatric symptoms: Psychiatric adverse events have been reported. 

Drug Interactions:

• Generally, no clinically important interactions: Reversair has been safely co-administered with many commonly used asthma therapies and other drugs, including theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, and decongestants. 
• Potent CYP450 Enzyme Inducers:
  • Phenobarbital: Decreased the AUC of Reversair by approximately 40%. 
  • Rifampin: Similar effects are anticipated. 
  • Clinical Monitoring: It is reasonable to employ appropriate clinical monitoring when potent cytochrome P450 enzyme inducers are co-administered with Reversair, though no dosage adjustment for Reversair is generally recommended. 

Overdose Effects

• In most overdosage reports, there were no adverse experiences. 
• Most frequently occurring adverse experiences (consistent with safety profile): Abdominal pain, somnolence (drowsiness), thirst, headache, vomiting, and psychomotor hyperactivity. 
• Management 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 & dry place below 30°C, protected from light & moisture. Keep out of reach of children.