Usage
- Desloratadine + Montelukast is prescribed for the treatment of allergic rhinitis (hay fever) and urticaria (hives). It is also sometimes used for other allergic conditions.
- Pharmacological Classification: This combination drug includes a second-generation antihistamine (Desloratadine) and a leukotriene receptor antagonist (Montelukast).
- Mechanism of Action: Desloratadine works by blocking the action of histamine, a chemical released by the body during an allergic reaction. Montelukast blocks the action of leukotrienes, another type of chemical involved in allergic and inflammatory responses. Together, they help to reduce the symptoms of allergies such as sneezing, runny nose, itching, and swelling.
Alternate Names
- No widely recognized alternate generic names exist for this combination. It is commonly referred to as Desloratadine + Montelukast or Desloratadine/Montelukast.
- Brand Names: Brand names may vary regionally; some examples include Drescap-M, Desrotac-M.
How It Works
- Pharmacodynamics: Desloratadine selectively blocks peripheral histamine H1 receptors, thereby reducing the effects of histamine. Montelukast antagonizes leukotriene D4 receptors, inhibiting the actions of cysteinyl leukotrienes, which are potent bronchoconstrictors and pro-inflammatory mediators.
- Pharmacokinetics:
- Absorption: Desloratadine is well-absorbed orally, reaching peak plasma concentration in about 3 hours. Montelukast is also absorbed well, with peak levels occurring in 3 to 4 hours.
- Metabolism: Both drugs are extensively metabolized in the liver. Desloratadine is primarily metabolized by CYP2C8 and CYP3A4, while montelukast is mainly metabolized by CYP2C8, CYP3A4, and CYP2C9.
- Elimination: Desloratadine is eliminated primarily through urine and feces, with a half-life of approximately 27 hours. Montelukast is also excreted mainly in feces, with a shorter half-life of 2.7 to 5.5 hours.
Dosage
Standard Dosage
Adults:
- Typically, one tablet containing 5 mg desloratadine and 10 mg montelukast is taken orally once daily. The dosage can be taken with or without food.
Children:
- The dosage for children under 12 years old should be determined by a pediatrician and depends on the child’s age and weight. Typically, for children aged 6-14 years, a 5 mg chewable montelukast tablet is prescribed daily, along with age-appropriate desloratadine dosing as determined by the pediatrician. For younger children, age and weight-based dosing applies for both drugs. The combination is generally not recommended for children under 2.
Special Cases:
- Elderly Patients: No specific dosage adjustments are typically necessary, but renal and hepatic function should be monitored.
- Patients with Renal Impairment: Dose adjustments are usually not necessary.
- Patients with Hepatic Dysfunction: Caution should be exercised in patients with hepatic impairment, and dosage adjustments may be considered.
- Patients with Comorbid Conditions: Patients with liver disease, asthma, phenylketonuria, or a history of seizures should be closely monitored, and dosage adjustments might be needed.
Clinical Use Cases
Desloratadine + Montelukast isn’t generally used for:
- Intubation
- Surgical Procedures
- Mechanical Ventilation
- Intensive Care Unit (ICU) Use
- Emergency Situations
Dosage Adjustments
Dosage adjustments are usually not necessary, but it is recommended to adjust dosages for children under 12 as per their specific medical needs.
Side Effects
Common Side Effects
- Headache
- Fatigue
- Dry mouth
- Abdominal pain
- Diarrhea
Rare but Serious Side Effects
- Allergic reactions (e.g., skin rash, itching, swelling)
- Behavioral changes (e.g., mood swings, anxiety, hallucinations)
- Liver problems (e.g., jaundice, dark urine)
- Neuropsychiatric events (e.g., agitation, aggression, suicidal ideation)
Long-Term Effects
Long-term effects of this combination are not well-studied but may include chronic complications related to any of the listed side effects, if persistent or severe.
Contraindications
- Hypersensitivity to desloratadine, montelukast, or any components of the formulation.
- Severe liver impairment
- Severe kidney impairment
Drug Interactions
- Phenobarbital, phenytoin, rifampicin, carbamazepine, fluoxetine, gemfibrozil, ketoconazole, erythromycin, and azithromycin can affect the metabolism of desloratadine or montelukast, altering their effectiveness.
- Grapefruit juice can increase the levels of both drugs.
- Alcohol can worsen the side effects, particularly drowsiness.
Pregnancy and Breastfeeding
- Pregnancy: Desloratadine + Montelukast is generally considered safe during pregnancy, but its use should be limited to situations where the benefits outweigh the risks. The pregnancy category is C.
- Breastfeeding: Desloratadine + Montelukast is excreted in breast milk. It’s generally considered safe but its use should be minimized to avoid potential adverse effects in infants. If necessary to use it, breastfeeding should be closely monitored by a doctor.
Drug Profile Summary
- Mechanism of Action: Blocks histamine and leukotriene pathways involved in allergic reactions.
- Side Effects: Headache, fatigue, dry mouth, abdominal pain, diarrhea, rare neuropsychiatric events.
- Contraindications: Hypersensitivity, severe liver/kidney impairment.
- Drug Interactions: Multiple drug interactions, including certain anticonvulsants, antibiotics, antifungals, grapefruit juice, alcohol.
- Pregnancy & Breastfeeding: Generally safe, but use with caution and under medical supervision.
- Dosage: Adults: one tablet (5 mg desloratadine/10 mg montelukast) orally once daily; Pediatric dosing should be determined by a physician.
- Monitoring Parameters: Liver function tests, renal function tests, observe for neuropsychiatric symptoms.
Popular Combinations
While Desloratadine + Montelukast itself is a combination, it may sometimes be prescribed with intranasal corticosteroids in cases of severe allergic rhinitis.
Precautions
- Patients with a history of mental health disorders should be monitored for neuropsychiatric symptoms.
- Patients with liver or kidney disease should be closely monitored.
- Driving should be avoided if drowsiness or dizziness occurs.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Desloratadine + Montelukast?
A: The standard adult dosage is one tablet (5mg desloratadine/10 mg montelukast) once daily. Pediatric dosing should be determined by a physician based on the age and weight of the child.
Q2: Can Desloratadine + Montelukast be taken during pregnancy?
A: It can be used during pregnancy if deemed necessary by a doctor, but the benefits must outweigh the potential risks.
Q3: Is this medication safe while breastfeeding?
A: It’s generally considered safe, but its use should be minimized and monitored to reduce the risk of potential side effects in the infant.
Q4: What are the most common side effects?
A: Headache, fatigue, dry mouth, abdominal pain, and diarrhea.
Q5: Are there any serious side effects?
A: Yes, rare but serious side effects can include allergic reactions, liver problems, behavioral changes, and neuropsychiatric events.
Q6: Can Desloratadine + Montelukast be used in children?
A: Yes, but dosing needs to be adjusted according to the child’s weight and age, under the supervision of a pediatrician.
Q7: Does this drug interact with other medications?
A: Yes, several drug interactions can occur, particularly with some anticonvulsants, antibiotics, and antifungals. Grapefruit juice can also interact. Consult a doctor for a comprehensive list.
Q8: Can I drink alcohol while taking Desloratadine + Montelukast?
A: It is recommended to avoid or limit alcohol consumption as it can worsen side effects like drowsiness.
Q9: 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 take your next dose at the regular time. Do not take a double dose to make up for a missed one.
