Usage
- Montelukast + Rupatadine is prescribed for the relief of symptoms associated with allergic rhinitis (hay fever) and urticaria (hives). It is also used for the prophylaxis and chronic treatment of asthma.
- Pharmacological Classification: Combined medication containing a leukotriene receptor antagonist (Montelukast) and a second-generation antihistamine (Rupatadine).
- Mechanism of Action: Montelukast blocks the action of leukotrienes, which are inflammatory mediators that contribute to bronchoconstriction, mucus secretion, and airway edema in asthma and allergic rhinitis. Rupatadine antagonizes histamine H1 receptors, reducing the effects of histamine release in allergic reactions like rhinitis and urticaria.
Alternate Names
- No widely recognized alternate generic names.
- Brand Names: Montilar Rup, Smarti M, and others.
How It Works
- Pharmacodynamics: Montelukast inhibits the effects of leukotrienes, leading to reduced bronchoconstriction, mucus secretion, and airway inflammation. Rupatadine blocks the effects of histamine at H1 receptors, mitigating symptoms like sneezing, itching, rhinorrhea, and urticaria.
- Pharmacokinetics:
- Absorption: Both drugs are orally absorbed. Food may slightly delay Montelukast absorption.
- Metabolism: Montelukast is primarily metabolized by CYP3A4 and CYP2C9 enzymes. Rupatadine’s metabolism is less extensively studied, but it is also likely metabolized by CYP3A4.
- Elimination: Both are primarily eliminated via hepatic metabolism and biliary excretion, with a small portion undergoing renal excretion.
- Mode of Action: Montelukast selectively binds to CysLT1 receptors, preventing leukotriene-mediated bronchoconstriction and inflammation. Rupatadine competitively binds to H1 receptors, preventing histamine from exerting its effects.
- Receptor Binding/Enzyme Inhibition: Montelukast is a CysLT1 receptor antagonist. Rupatadine is an H1 receptor antagonist. Information on CYP enzyme inhibition by Rupatadine is limited. Montelukast is metabolized by CYP3A4 and CYP2C9 and may be impacted by inhibitors or inducers of these enzymes.
- Elimination Pathways: Primarily hepatic metabolism and biliary excretion, with minimal renal excretion for both drugs.
Dosage
Standard Dosage
Adults: One tablet containing 10 mg Montelukast and 10 mg Rupatadine once daily, taken with or without food.
- 6 months to 5 years: 4 mg Montelukast daily.
- 6 to 14 years: 5 mg Montelukast daily.
- 15 years and older: 10 mg Montelukast daily.
Special Cases:
- Elderly Patients: Rupatadine should be used with caution. No dosage adjustment is usually necessary for Montelukast.
- Patients with Renal Impairment: Rupatadine use is not recommended in patients with renal impairment. Montelukast dosage adjustment is not usually necessary.
- Patients with Hepatic Dysfunction: Rupatadine use is not recommended in patients with hepatic impairment. Montelukast dosage adjustment is not usually necessary.
- Patients with Comorbid Conditions: Dose adjustments may be required; consultation with specialist advised.
Clinical Use Cases
Montelukast + Rupatadine is not typically used in the context of intubation, surgical procedures, mechanical ventilation, intensive care, or emergency situations like status epilepticus or cardiac arrest.
Dosage Adjustments
Dosage adjustments should be considered based on individual patient characteristics, such as renal or hepatic impairment, drug interactions and comorbid conditions.
Side Effects
Common Side Effects: Headache, dizziness, fatigue, drowsiness, dry mouth, nausea, diarrhea, rash, flu-like symptoms, and upper respiratory tract infection.
Rare but Serious Side Effects: Neuropsychiatric events (e.g., mood changes, agitation, anxiety, depression, hallucinations, suicidal ideation), hepatic dysfunction, angioedema, Churg-Strauss syndrome, and eosinophilic granulomatosis with polyangiitis.
Long-Term Effects: Not well established, but some neuropsychiatric effects may persist.
Adverse Drug Reactions (ADR): Anaphylaxis, hepatotoxicity, and severe skin reactions.
Contraindications
- Hypersensitivity to montelukast or rupatadine.
- Severe hepatic impairment.
- Severe renal impairment.
- Use with strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin).
Drug Interactions
- Strong CYP3A4 inhibitors: May increase plasma concentrations of both drugs.
- Moderate CYP3A4 inhibitors: Use with caution.
- Statins: Monitor for potential interactions.
- Alcohol: May increase drowsiness, especially with rupatadine.
- Grapefruit juice: Should be avoided, as it may increase rupatadine levels.
- Gemfibrozil, erythromycin, phenytoin, phenobarbital, and ketoconazole: May interact with the combination.
Pregnancy and Breastfeeding
- Pregnancy: Montelukast is generally considered safe during pregnancy. Limited data are available for rupatadine, and it should only be used if the potential benefit outweighs the risk.
- Breastfeeding: Both drugs are excreted in breast milk in small amounts. Monitor infants for potential side effects.
Drug Profile Summary
- Mechanism of Action: Leukotriene receptor antagonist and antihistamine.
- Side Effects: Headache, dizziness, drowsiness, dry mouth, nausea, etc. Rarely: neuropsychiatric events, hepatic dysfunction.
- Contraindications: Hypersensitivity, severe hepatic/renal impairment, strong CYP3A4 inhibitors.
- Drug Interactions: CYP3A4 inhibitors, statins, alcohol, grapefruit juice.
- Pregnancy & Breastfeeding: Montelukast generally considered safe during pregnancy. Limited data for rupatadine. Both are excreted in breast milk.
- Dosage: Adults: 10 mg/10 mg once daily. Children: Montelukast dosing varies by age.
- Monitoring Parameters: Liver function tests, mental status, and allergic symptoms.
Popular Combinations
- Often used as a single combination product.
- May be combined with other medications for asthma or allergic rhinitis if symptoms are not adequately controlled.
Precautions
- General Precautions: Assess for pre-existing conditions, drug allergies, and potential drug interactions.
- Specific Populations: Use with caution in the elderly, patients with renal or hepatic impairment, and during pregnancy and breastfeeding.
- Lifestyle Considerations: Limit alcohol intake due to potential increased drowsiness. Avoid operating machinery until effects on alertness are known.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Montelukast + Rupatadine?
A: For adults, one tablet containing 10 mg of each drug once daily. Pediatric dosing for Montelukast varies based on age and formulation. Rupatadine is not recommended for children under 12 years.
Q2: What are the common side effects?
A: Headache, dizziness, drowsiness, dry mouth, nausea, diarrhea, and fatigue.
Q3: Are there any serious side effects?
A: Rarely, neuropsychiatric events, hepatic dysfunction, and severe allergic reactions can occur.
Q4: Can this combination be used during pregnancy?
A: Montelukast is generally considered safe. Rupatadine use should be carefully considered and used only if the potential benefit outweighs the risk.
Q5: Is it safe to breastfeed while taking this medication?
A: Both drugs are excreted in breast milk. Monitor infants for potential side effects. Discuss risks and benefits with the patient.
Q6: What are the main drug interactions to be aware of?
A: Avoid strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin). Caution with moderate CYP3A4 inhibitors, statins, alcohol, and grapefruit juice.
Q7: How does Montelukast + Rupatadine work in allergic rhinitis?
A: Montelukast addresses the leukotriene-mediated inflammatory component, while rupatadine blocks histamine’s effects, providing comprehensive symptom relief.
Q8: Is there a specific time of day to take this medication?
A: Can be taken with or without food at any time of day.
Q9: What should I do if a dose is missed?
A: Take the missed dose as soon as possible, unless it is close to the next scheduled dose. Do not double the dose.
Q10: What are the contraindications for this combined medication?
A: Hypersensitivity to either drug, severe hepatic or renal impairment, and concomitant use of strong CYP3A4 inhibitors.
