Drug Guide

Generic Name

Loratadine

Brand Names Claritin, Claritin Hives Relief, Claritin Reditabs, Claritin Hives Relief Reditab, Alavert, Children's Claritin, Loratadine Redidose

Classification

Therapeutic: Antihistamine for allergy relief

Pharmacological: Selective peripheral H1 antihistamine

FDA Approved Indications

Relief of allergic rhinitis symptoms (runny nose, sneezing, nasal congestion, watery eyes, itching)
Chronic idiopathic urticaria (hives)

Mechanism of Action

Loratadine selectively antagonizes peripheral H1 histamine receptors, reducing the effects of histamine in allergy symptoms without significant central nervous system sedation.

Dosage and Administration

Adult: 10 mg once daily

Pediatric: 2-5 years: 5 mg once daily; 6 years and older: 10 mg once daily

Geriatric: Same as adult, cautious use due to potential polypharmacy and comorbidities

Renal Impairment: Adjust dose in severe impairment, typically 10 mg every other day

Hepatic Impairment: Use with caution; no specific dose adjustment recommended

Pharmacokinetics

Absorption: Rapidly absorbed, peak plasma levels in 1-2 hours

Distribution: Widely distributed, crosses placenta, minimal CNS penetration due to P-glycoprotein efflux

Metabolism: Mainly metabolized hepatically via CYP3A4 and CYP2D6 pathways

Excretion: Excreted mainly in feces and urine; unchanged drug in feces and metabolites in urine

Half Life: Approximately 8 hours

Contraindications

Hypersensitivity to loratadine or other antihistamines
Pregnancy Category B (use with caution; consult provider)

Precautions

Use with caution in hepatic impairment, may cause or worsen arrhythmias, avoid concurrent use with other QT-prolonging drugs

Adverse Reactions - Common

Headache (Common)
Somnolence (less than first-generation antihistamines) (Less common, but possible)
Fatigue (Common)

Adverse Reactions - Serious

QT prolongation / arrhythmias (Rare)
Anaphylaxis (Rare)
Hepatic impairment (Rare)

Drug-Drug Interactions

CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) may increase loratadine levels
CNS depressants may enhance sedative effects

Drug-Food Interactions

Grapefruit juice may inhibit CYP3A4, potentially increasing loratadine levels

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Evaluate for allergy symptom relief and monitor for adverse effects, especially in patients with hepatic or cardiac issues.

Diagnoses:

Ineffective breathing pattern related to allergy symptoms
Risk for adverse drug reactions

Implementation: Administer on an empty stomach for faster absorption, or with food if GI upset occurs.

Evaluation: Assess effectiveness in symptom relief and monitor for adverse reactions.

Patient/Family Teaching

Take loratadine as directed, usually once daily.
Report any signs of allergic reactions or unusual side effects.
Use caution when operating machinery or driving until effects are known.
Inform healthcare provider of all medications and supplements.

Special Considerations

Black Box Warnings:

None currently

Genetic Factors: Metabolized by CYP2D6; poor metabolizers may have increased drug levels

Lab Test Interference: May interfere with skin allergy tests, leading to false negatives

Overdose Management

Signs/Symptoms: Drowsiness, headache, tachycardia, fatigue, dry mouth

Treatment: Supportive care, activated charcoal if recent ingestion, and monitoring of cardiac function if overdose is severe.

Storage and Handling

Storage: Store at room temperature, 15-30°C (59-86°F).

Stability: Stable under normal conditions; protect from moisture.