Duvent

Approved Indications:

• Allergic Rhinitis (Seasonal and Perennial):
  For the symptomatic treatment of nasal and non-nasal symptoms such as sneezing, rhinorrhea, nasal congestion, nasal itching, and ocular symptoms (itching, tearing) in adults, adolescents, and children aged ≥2 years.
• Chronic Idiopathic Urticaria (CIU):
  For the relief of pruritus and reduction in the number and size of wheals in patients aged ≥2 years.

Clinically Accepted Off-Label Uses:

• Atopic Dermatitis (Histamine-mediated itching):
  Occasionally used as adjunctive therapy to relieve pruritus in inflammatory skin disorders.
• Mastocytosis-related pruritus and urticaria:
  Used in select cases to manage mast cell-related allergic symptoms due to its dual H1 and PAF antagonism.

Route of Administration: Oral (Tablets and Oral Solution)

Adults and Adolescents (≥12 years):

• 10 mg orally once daily

Children 6 to 11 years:

• 5 mg orally once daily (usually as oral solution)

Children 2 to 5 years:

• 2.5 mg orally once daily (oral solution)

Elderly Patients:

• No dose adjustment typically required; however, due to limited clinical data, use with caution.

Renal Impairment:

• Limited data available; use cautiously without initial dose adjustment but monitor closely in moderate to severe impairment.

Hepatic Impairment:

• Use not recommended in severe hepatic impairment due to lack of safety data; caution advised in mild to moderate impairment.

Administration Instructions:

• May be taken with or without food.
• Administer at the same time each day to maintain consistent plasma levels.

Rupatadine is a long-acting, non-sedating second-generation antihistamine. It acts as a selective antagonist of peripheral H1-histamine receptors and also exhibits antagonistic activity against platelet-activating factor (PAF) receptors. Histamine and PAF are both key mediators in allergic inflammation. By simultaneously blocking both, rupatadine reduces capillary permeability, edema, itching, and wheal formation. Its dual mechanism contributes to its effectiveness in both allergic rhinitis and chronic urticaria with minimal sedation due to low penetration across the blood-brain barrier.

• Absorption: Rapid and nearly complete after oral administration; peak plasma concentration reached in ~0.75–1.5 hours.
• Bioavailability: Approx. 34% (absolute); increased when taken with high-fat meals.
• Distribution: Widely distributed; ~98–99% bound to plasma proteins.
• Metabolism: Extensively metabolized in the liver primarily via CYP3A4. Active metabolites include desloratadine and 3-hydroxydesloratadine.
• Elimination Half-life: Parent compound: 5.9–6.3 hours; active metabolites: 8.7–9.3 hours.
• Excretion: Mainly via feces; minor urinary excretion.

Pregnancy:

• No FDA pregnancy category assigned under the new labeling system.
• Animal studies did not demonstrate teratogenicity. However, human data are limited.
• Should only be used during pregnancy if the expected benefit justifies the potential risk.

Lactation:

• Unknown if excreted in human breast milk.
• Due to lack of data and potential risk, caution is advised. Either discontinue the drug or avoid breastfeeding if therapy is essential.

• Primary Class: Non-sedating Second-Generation Antihistamine
• Sub-class: Dual H1 Antihistamine and Platelet-Activating Factor (PAF) Antagonist

• Hypersensitivity to rupatadine or any of its components
• Severe hepatic impairment
• Co-administration with strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin)
• Known or suspected QT interval prolongation or patients at risk for arrhythmias

• Cardiac Risk: Use with caution in patients with prolonged QT interval or those on other QT-prolonging agents.
• Hepatic Impairment: Not recommended in severe hepatic disease due to altered metabolism.
• Renal Impairment: Monitor closely; limited clinical data in severe impairment.
• CNS Depression: Though non-sedating, concurrent use with alcohol or CNS depressants may cause somnolence.
• Pediatric Use: Use age-appropriate dosage forms; safety not established under 2 years.

Common Adverse Effects (≥1%):

• Nervous System: Headache, dizziness, fatigue, somnolence
• Gastrointestinal: Dry mouth, nausea
• Respiratory: Nasopharyngitis, cough (notably in children)

Uncommon or Rare Side Effects:

• Palpitations, tachycardia
• Mild elevations in liver enzymes
• Skin rash or pruritus

Serious Side Effects (Rare):

• Anaphylaxis
• QT interval prolongation (usually in overdose or with interacting drugs)

Onset & Severity:

• Generally mild and transient
• Onset within first few days of treatment
• Most side effects are not dose-dependent

Major Interactions:

• CYP3A4 Inhibitors (e.g., ketoconazole, ritonavir, erythromycin): May increase rupatadine plasma levels and risk of QT prolongation.
• Grapefruit Juice: Inhibits CYP3A4; may elevate drug levels.
• Alcohol/CNS Depressants: Can enhance CNS depressant effects like drowsiness.

Moderate Interactions:

• Macrolides & Azole Antifungals: Increased risk of cardiac effects.
• Other Antihistamines: Additive anticholinergic or sedative effects.

Enzymatic System:

• Primarily metabolized by CYP3A4.

• Pediatric Extension Approved in EU: Use of oral solution approved down to 2 years of age in allergic rhinitis and urticaria.
• Continued Endorsement in Clinical Guidelines: Included as a preferred second-generation antihistamine with dual action in updated EAACI and ARIA guidelines.
• No Major Labeling Changes: No new safety alerts or indication changes reported by FDA or EMA as of 2025.

Rupatadine Tablets:

• Store below 30°C
• Protect from moisture and direct light
• Keep in original packaging

Rupatadine Oral Solution:

• Store below 25°C
• Do not freeze
• Protect from light
• Shake well before use
• Keep bottle tightly closed