One-A-Day Allergy And Hayfever Relief (Loratadine)

Loratadine is an H1‑receptor antagonist that reduces allergic symptoms by blocking histamine activity.

• Seasonal allergic rhinitis: alleviates sneezing, nasal congestion, runny nose and itchy eyes.
• Chronic urticaria: reduces the frequency and severity of hives and associated itching.
• Allergic conjunctivitis: eases eye irritation, redness and watering caused by allergens.

• Loratadine selectively blocks peripheral H1 histamine receptors, preventing histamine‑induced vasodilation, increased vascular permeability and sensory nerve stimulation. By inhibiting this pathway, it reduces the typical signs of an allergic response without significant sedation, as it does not readily cross the blood‑brain barrier.

Adverse reactions to loratadine are generally mild and reversible.

Common Side Effects

• Headache: mild to moderate intensity.
• Dry mouth: transient sensation of oral dryness.
• Fatigue: occasional tiredness not interfering with daily activities.
• Nausea: mild stomach upset.
• Drowsiness (rare): low‑grade sleepiness in sensitive individuals.

Serious or Rare Side Effects

• Stevens‑Johnson syndrome: severe skin reaction requiring immediate medical attention.
• Angio‑edema: swelling of face, lips or tongue.
• Hepatotoxicity: abnormal liver function tests.
• Hematologic abnormalities: eosinophilia or thrombocytopenia.
• Anaphylaxis: acute, life‑threatening allergic reaction.

Before using loratadine, consider the following safety measures:

• Pregnancy: consult the prescriber if you are pregnant or planning pregnancy.
• Breastfeeding: discuss potential risks with a healthcare professional.
• Liver impairment: dose may need adjustment in moderate to severe hepatic dysfunction.
• Concomitant sedatives: monitor for enhanced drowsiness when combined with CNS depressants.
• Age restrictions: not recommended for children under 2 years without medical advice.
• Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.

Loratadine may interact with several medicines; monitoring is advised.

Major Interactions (Avoid)

• Erythromycin: may increase loratadine plasma levels, raising risk of side effects.
• Ketoconazole: can elevate systemic exposure and potentiate adverse reactions.
• Ritonavir: strong CYP3A4 inhibition may raise loratadine concentrations.

Moderate Interactions (Monitor Closely)

• Theophylline: may experience altered theophylline levels.
• Antihistamine combinations: additive sedation or anticholinergic effects.
• Alcohol: may enhance drowsiness in susceptible individuals.