Desloratadine for Allergy and Urticaria Relief

Desloratadine is an oral antihistamine medication used to relieve symptoms associated with allergic conditions such as seasonal and perennial allergic rhinitis and chronic idiopathic urticaria. Available in tablets, orally disintegrating tablets, and oral solution, it works by blocking histamine receptors, thereby reducing allergy symptoms like sneezing, runny nose, and itching.

Desloratadine is indicated for:

• Relief of nasal and non-nasal symptoms of seasonal allergic rhinitis in patients 2 years of age and older (12 years and older for regular tablets).
• Relief of nasal and non-nasal symptoms of perennial allergic rhinitis in patients 6 months of age and older (12 years and older for regular tablets).
• Symptomatic relief of pruritus and reduction in the number and size of hives associated with chronic idiopathic urticaria in patients 6 months of age and older (12 years and older for regular tablets).

Desloratadine

Desloratadine is a long-acting tricyclic antihistamine that selectively blocks H1 histamine receptors, which helps to prevent the effects of histamine, a chemical involved in allergic reactions. It inhibits histamine release from mast cells and produces an anti-allergic effect within about 1 hour of administration, lasting up to 24 hours. It poorly penetrates the blood-brain barrier, minimizing sedative effects.

General Dosing

• Adults and adolescents 12 years and older: 5 mg once daily (regular tablets or orally disintegrating tablets or oral solution).
• Children 6 to 11 years: 2.5 mg once daily (orally disintegrating tablets or equivalent oral solution dose).
• Children 12 months to 5 years: 1.25 mg once daily (oral solution).
• Children 6 months to 11 months: 1 mg once daily (oral solution).
• The oral solution is dosed by volume: 0.5 mg/mL concentration.

Administration

• Can be taken with or without food.
• Orally disintegrating tablets should be placed on the tongue and allowed to disintegrate before swallowing; can be taken with or without water.
• Use a calibrated dropper or syringe with oral solution.

Special Populations

• Patients with hepatic or renal impairment: start with 5 mg every other day for adults; no pediatric dosing recommendations due to lack of data.

Desloratadine is contraindicated in patients with known hypersensitivity to desloratadine, loratadine, or any components of the formulation.

Hypersensitivity Reactions

Serious allergic reactions including rash, itching, hives, swelling, difficulty breathing, and anaphylaxis have been reported. Discontinue desloratadine immediately if such reactions occur and consider alternative treatment.

Common Adverse Reactions (≥2% in adults/adolescents)

• Pharyngitis
• Dry mouth
• Myalgia (muscle pain)
• Fatigue
• Somnolence (drowsiness)
• Dysmenorrhea (menstrual pain)

Chronic Idiopathic Urticaria Associated Adverse Events (≥2% and greater than placebo)

• Headache
• Nausea
• Fatigue
• Dizziness
• Pharyngitis
• Dyspepsia
• Myalgia

Pediatric Adverse Events (6 months to 11 years, varying by age)

• Upper respiratory tract infections
• Diarrhea
• Fever
• Irritability
• Coughing
• Somnolence
• Bronchitis
• Otitis media
• Vomiting
• Other minor infections and symptoms

Rarely Reported Spontaneous Events

• Tachycardia, palpitations
• Psychomotor hyperactivity, seizures
• Hypersensitivity reactions including anaphylaxis
• Elevated liver enzymes and rarely hepatitis

Co-administration with ketoconazole, erythromycin, azithromycin, fluoxetine (SSRI), or cimetidine (H2 antagonist) increases plasma concentration of desloratadine and its active metabolite but does not cause clinically relevant safety changes.

Pregnancy

Desloratadine is Pregnancy Category C. Animal studies have not shown teratogenic effects at high exposures, but data in pregnant women are insufficient. Use during pregnancy only if clearly needed.

Lactation

Desloratadine passes into breast milk. The decision to discontinue nursing or the drug should consider the benefits of breastfeeding and the necessity of desloratadine for the mother.

In case of overdose, perform standard procedures to remove unabsorbed drug and provide symptomatic and supportive treatment. Desloratadine and its active metabolite are not removed by hemodialysis.