Levocetirizine Zydus (Levocetirizine Dihydrochloride)

Levocetirizine is an H1 antihistamine that acts on allergic and urticarial conditions.

• Allergic rhinitis: reduces nasal congestion, sneezing, itching and rhinorrhea.
• Seasonal allergic rhinitis: alleviates symptoms triggered by pollen or seasonal allergens.
• Chronic idiopathic urticaria: diminishes wheal formation, itching and hives, improving quality of life.

• Levocetirizine selectively blocks peripheral H1 histamine receptors, preventing histamine from binding and activating these receptors. By inhibiting this pathway, it reduces the vascular permeability, sensory nerve stimulation, and smooth‑muscle contraction that underlie the clinical manifestations of allergic reactions and urticaria.

Levocetirizine is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Drowsiness: mild to moderate sleepiness, especially at treatment initiation.
• Fatigue: a feeling of reduced energy.
• Dry mouth: decreased salivation.
• Headache: mild to moderate cranial pain.
• Nausea: occasional stomach upset.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips or tongue requiring urgent care.
• Severe skin rash or Stevens‑Johnson syndrome: extensive epidermal detachment.
• Anaphylaxis: rapid onset of systemic allergic reaction.
• Hepatic dysfunction: abnormal liver enzymes.
• Thrombocytopenia: low platelet count with potential bleeding risk.

Before initiating therapy, consider patient‑specific factors and safety measures.

• Pregnancy: consult a healthcare professional before use; risk‑benefit assessment is required.
• Renal impairment: evaluate renal function; dose adjustment may be necessary.
• Elderly patients: monitor for increased sedation or confusion.
• Driving or operating machinery: avoid until individual response to the drug is known.
• Concomitant medications: review all current drugs for potential interactions.
• Store at ambient temperature: keep in the original packaging, protect from moisture and direct sunlight.

Levocetirizine may interact with other substances that affect the central nervous system or its metabolism.

Major Interactions (Avoid)

• Alcohol: can potentiate sedation and impair cognition.
• CNS depressants (e.g., benzodiazepines, barbiturates): additive drowsiness.
• Strong CYP3A4 inhibitors (e.g., ketoconazole): may increase levocetirizine plasma concentrations.

Moderate Interactions (Monitor Closely)

• Ritonavir: may raise drug levels, requiring observation.
• Erythromycin: potential modest increase in exposure.
• Diphenhydramine or other antihistamines: risk of cumulative anticholinergic effects.