Usage
- Fexofenadine + Montelukast is prescribed for the relief of symptoms associated with allergic rhinitis (hay fever) and chronic urticaria (hives). Symptoms include sneezing, runny nose, nasal congestion, itching, and watery eyes. It also helps in managing asthma symptoms.
- Pharmacological Classification: This combination drug includes a second-generation antihistamine (Fexofenadine) and a leukotriene receptor antagonist (Montelukast).
- Mechanism of Action: Fexofenadine competitively inhibits peripheral histamine H1-receptors, reducing the effects of histamine released during an allergic reaction. Montelukast blocks the action of leukotrienes, which are inflammatory chemicals that contribute to allergy and asthma symptoms.
Alternate Names
- There are no widely recognized alternate generic names for this combination. The individual components are sometimes referred to as Fexofenadine Hydrochloride and Montelukast Sodium.
- Brand Names: This combination is marketed under various brand names such as Allegra-M, Fexomont, and Montek LC among others. Brand names can vary regionally.
How It Works
- Pharmacodynamics: Fexofenadine reduces the vascular permeability and smooth muscle contraction caused by histamine. Montelukast inhibits bronchoconstriction, mucus secretion, and eosinophil recruitment induced by leukotrienes.
- Pharmacokinetics:
- Fexofenadine: Rapidly absorbed after oral administration, reaching peak plasma concentration in about 1 to 3 hours. Minimally metabolized in the liver, primarily excreted unchanged in the feces and urine.
- Montelukast: Rapidly absorbed after oral administration. Extensively metabolized in the liver primarily by CYP3A4 and 2C9 enzymes. Excreted mainly in the bile.
- Mode of Action: Fexofenadine exerts its effect by selectively binding to and blocking the peripheral H1 histamine receptors. Montelukast selectively binds to and blocks the CysLT1 receptor, inhibiting the action of leukotrienes.
- Elimination Pathways: Fexofenadine is eliminated through both renal and fecal routes. Montelukast is eliminated primarily through biliary excretion with minimal renal excretion.
Dosage
Standard Dosage
Adults:
- One tablet of Fexofenadine 120 mg + Montelukast 10 mg once daily, preferably in the evening.
Children:
- Fexofenadine alone is recommended for children aged 6 months and older. Montelukast alone is approved for children as young as 6 months for asthma and 2 years old for allergic rhinitis. For combination use, clinical guidelines often recommend against its use in children under 12 years of age. Pediatric dosing should always be determined by a physician, taking into account age, weight, and specific medical conditions.
Special Cases:
- Elderly Patients: No specific dose adjustments are typically required unless significant renal or hepatic impairment is present.
- Patients with Renal Impairment: Dose adjustment may be necessary. Consider initiating Fexofenadine at a lower dose (e.g., 60 mg once daily). Montelukast dose adjustment is not usually required.
- Patients with Hepatic Dysfunction: Fexofenadine dose adjustment is generally not necessary. For Montelukast, no specific dose adjustments are typically required. However, caution should be exercised.
- Patients with Comorbid Conditions: Caution should be exercised in patients with cardiovascular disease or neuropsychiatric disorders.
Clinical Use Cases
The combination of Fexofenadine and Montelukast is not typically indicated for acute management in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. Its primary use is for chronic allergy management.
Dosage Adjustments
Dose adjustments are primarily based on renal function for Fexofenadine. Always follow clinical guidelines and consult drug information resources for specific recommendations.
Side Effects
Common Side Effects
- Headache
- Dizziness
- Drowsiness
- Nausea
- Vomiting
- Diarrhea
- Fatigue
- Skin rash
Rare but Serious Side Effects
- Severe allergic reactions (anaphylaxis)
- Mood changes, depression, suicidal ideation
- Churg-Strauss syndrome (rare)
Long-Term Effects
Long-term effects of combined use are not extensively studied. Monitor for potential neuropsychiatric effects with Montelukast.
Adverse Drug Reactions (ADR)
Any severe or unusual reactions should be reported immediately.
Contraindications
- Hypersensitivity to Fexofenadine or Montelukast
- Severe hepatic impairment (use with caution)
Drug Interactions
- CYP450 interactions: Montelukast is metabolized by CYP3A4 and 2C9. Co-administration with strong inducers (e.g., phenobarbital, rifampin) or inhibitors (e.g., ketoconazole, erythromycin) of these enzymes may alter Montelukast levels. Fexofenadine is not extensively metabolized by CYP enzymes.
- Interactions with:
- Antacids containing aluminum or magnesium (reduce absorption of Fexofenadine and Montelukast - take at least 2 hours apart).
- Certain fruit juices like grapefruit, apple, and orange juice (can reduce effectiveness of Fexofenadine)
Pregnancy and Breastfeeding
- Pregnancy Safety Category: Fexofenadine: Category C (US FDA). Montelukast: Category B (US FDA).
- The safety of this combination during pregnancy is not well established. Use only if clearly needed and the potential benefits outweigh the risks.
- Both Fexofenadine and Montelukast can pass into breast milk, however in small amounts. Consult a physician regarding breastfeeding while taking this medication.
Drug Profile Summary
Please refer to the sections above for detailed explanations of each point.
Popular Combinations
Fexofenadine and Montelukast are often prescribed together. Sometimes, they are combined with other medications like nasal corticosteroids for more severe allergic rhinitis.
Precautions
Please refer to the sections above for detailed precautions related to specific populations and lifestyle considerations.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Fexofenadine + Montelukast?
A: The standard adult dosage is one tablet of Fexofenadine 120 mg + Montelukast 10 mg taken orally once daily, usually in the evening.
Q2: Can this combination be used in children?
A: It is generally not recommended for children under 12 years of age. A physician should determine the appropriate dosing and medication for younger children.
Q3: Are there any drug interactions I should be aware of?
A: Yes. Avoid antacids containing aluminum or magnesium within 2 hours of taking Fexofenadine + Montelukast. Also, avoid grapefruit, apple, and orange juices as they may affect drug absorption.
Q4: Can I take this medicine if I am pregnant or breastfeeding?
A: Consult your physician before using this medication if you are pregnant or breastfeeding. The safety in these situations is not fully established.
Q5: What are the common side effects?
A: Common side effects include headache, dizziness, drowsiness, nausea, vomiting, diarrhea, fatigue, and skin rash.
Q6: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your regular schedule. Do not double the dose to catch up.
Q7: Is Fexofenadine + Montelukast an antibiotic?
A: No, it is not an antibiotic. It is used to treat allergy symptoms.
Q8: Can this combination be used to treat acute asthma attacks?
A: No, this combination is not suitable for treating acute asthma attacks. Patients should use their prescribed rescue inhaler for acute episodes.
Q9: How long should I take this medication?
A: You should continue taking this medication as long as your doctor recommends. Do not stop taking it abruptly without consulting your physician.
Q10: Can I drink alcohol while taking this medicine?
A: It is generally recommended to avoid alcohol while taking this medication as it can increase drowsiness and other side effects.
