Loratadine: Overview
Introduction
- Loratadine is an antihistamine used to relieve allergy symptoms such as runny nose, sneezing, and itchy eyes.
Mechanism of Action (MOA)
- Histamine Receptor Antagonist : Loratadine works by blocking histamine H1 receptors. Histamine is a substance in the body that causes allergic symptoms.
- Non-Sedating : Unlike some older antihistamines, loratadine does not easily cross the blood-brain barrier, which minimizes its sedative effects.
Uses
- Allergic Rhinitis : Treats symptoms like runny nose, sneezing, and itching caused by hay fever or other upper respiratory allergies.
- Chronic Urticaria : Relieves itching and hives (urticaria) associated with chronic skin reactions.
Dosage
- Adults and Children (6 years and older) : Typically, 10 mg once daily.
- Children (2-5 years) : Generally, 5 mg once daily (often in syrup form).
Side Effects
- Common Side Effects :
- Headache
- Dry mouth
- Fatigue
- Drowsiness (less common compared to first-generation antihistamines)
- Rare Side Effects :
- Dizziness
- Nervousness
- Increased heart rate
- Stomach pain
- Jaundice (very rare)
Precautions
- Liver Impairment : Patients with liver disease may require a lower dose.
- Pregnancy and Breastfeeding : Consult a doctor before use.
- Drug Interactions : Caution with other CNS depressants and medications metabolized by the liver.
Key Points
- Non-Sedating : Preferred for individuals who need to avoid drowsiness.
- OTC Availability : Widely available over the counter.
- Quick Relief : Provides relief from allergy symptoms within 1-3 hours.
By understanding these points, patients and healthcare providers can effectively use loratadine to manage allergic conditions.