Desloratidine

# Desloratidine ## Overview - **Classification**: Second-generation tricyclic antihistamine; H1-receptor antagonist. - **Mechanism**: Selective peripheral H1-receptor antagonist, blocking histamine's effects without significant CNS penetration. ## Primary Indications 1. **Seasonal Allergic Rhinitis (SAR)** - Relief of nasal and non-nasal symptoms. 2. **Perennial Allergic Rhinitis (PAR)** - Relief of nasal and non-nasal symptoms. 3. **Chronic Idiopathic Urticaria (CIU)** - Relief of pruritus and reduction in number/size of hives. ## Adult Dosing ### Standard Dosing **Allergic Rhinitis (SAR/PAR) & Chronic Idiopathic Urticaria (CIU)** - **Dose**: **5 mg** - **Frequency**: Once daily - **Route**: Oral - **Duration**: As needed for symptom control ### Dose Adjustments - **Renal Impairment**: For severe renal impairment (CrCl <30 mL/min), consider **5 mg every other day**. - **Hepatic Impairment**: For hepatic impairment, consider **5 mg every other day**. - **Elderly Patients**: No specific dose adjustment needed based on age alone, but consider renal/hepatic function. ## Pediatric Dosing ### Neonates (0-28 days) - Desloratadine is **not recommended** for this age group. - **Special Notes**: Safety and efficacy not established. ### Infants (6-11 months) - **Indication**: Chronic Idiopathic Urticaria. - **Dose**: **1 mg** (2 mL of 0.5 mg/mL oral solution) - **Frequency**: Once daily - **Maximum**: **1 mg** per day - **Special Notes**: Use oral solution; measure carefully. ### Children (1-5 years) - **Indication**: Allergic Rhinitis, Chronic Idiopathic Urticaria. - **Dose**: **1.25 mg** (2.5 mL of 0.5 mg/mL oral solution) - **Frequency**: Once daily - **Maximum**: **1.25 mg** per day - **Special Notes**: Use oral solution; measure carefully. ### Children (6-11 years) - **Indication**: Allergic Rhinitis, Chronic Idiopathic Urticaria. - **Dose**: **2.5 mg** (either one 2.5 mg tablet or 5 mL of 0.5 mg/mL oral solution) - **Frequency**: Once daily - **Maximum**: **2.5 mg** per day ### Adolescents (12-18 years) - **Indication**: Allergic Rhinitis, Chronic Idiopathic Urticaria. - **Dose**: **5 mg** (adult dose) - **Frequency**: Once daily - **Maximum**: **5 mg** per day ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to desloratadine, loratadine, or any component of the formulation. ### Common Adverse Effects - **Common (1-10%)**: Headache, dry mouth, fatigue. - **Less Common (1-10%)**: Somnolence (less than first-gen antihistamines), pharyngitis, nausea, dizziness. - **Serious but Rare**: Hypersensitivity reactions (anaphylaxis, angioedema, rash), seizures (very rare, mostly in predisposed patients). ### Key Drug Interactions - **Ketoconazole, Erythromycin, Azithromycin, Cimetidine, Fluoxetine**: May increase desloratadine plasma levels; clinical significance usually minor. - **Alcohol**: Desloratadine does not potentiate the effects of alcohol. ## Monitoring & Follow-up - **Before Treatment**: No specific baseline tests required. - **During Treatment**: Monitor for symptom improvement and adverse effects. - **Clinical Signs**: Watch for signs of hypersensitivity reactions (rash, swelling, difficulty breathing) or unusual neurological symptoms. ## Clinical Pearls - 💡 **Non-Sedating**: Generally considered non-sedating at recommended doses, allowing daily activities. - 💡 **Flexible Dosing**: Can be taken with or without food. - 💡 **Pediatric Formulation**: Oral solution available for younger children for precise dosing. - 💡 **Onset of Action**: Symptom relief typically begins within 1-3 hours. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.