Levocetirizin Krka (Levocetirizine Dihydrochloride)

Levocetirizin is an antihistamine that acts on the H1‑receptor pathway to alleviate allergic conditions.

• Allergic rhinitis: reduces nasal congestion, sneezing, itching and watery eyes associated with seasonal or perennial allergens.
• Chronic idiopathic urticaria: diminishes the frequency and severity of hives and associated itching.
• Allergic conjunctivitis: alleviates eye redness, itching and tearing caused by allergen exposure.

• Levocetirizine Dihydrochloride is a selective peripheral H1‑receptor antagonist. By binding with high affinity to histamine H1 receptors on mast cells, basophils and vascular endothelium, it prevents histamine‑induced vasodilation, increased vascular permeability and sensory nerve stimulation. This blockade reduces the classic symptoms of allergic reactions without crossing the blood‑brain barrier in significant amounts, thereby limiting central nervous system effects.

Levocetirizin may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Drowsiness: mild to moderate sleepiness, especially after the first dose.
• Fatigue: general feeling of tiredness.
• Dry mouth: reduced salivation leading to a dry oral cavity.
• Headache: mild to moderate head pain.
• Nausea: occasional stomach upset.
• Taste disturbance: altered perception of flavors.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue or throat requiring immediate medical attention.
• Anaphylactic reaction: severe, rapid‑onset allergic response that can be life‑threatening.
• Blood dyscrasias: rare cases of neutropenia or thrombocytopenia.

Before prescribing Levocetirin, clinicians should consider several precautionary measures to ensure safe use.

• Renal function assessment: adjust dose in patients with severe renal impairment.
• Concomitant CNS depressants: avoid or monitor use with alcohol, benzodiazepines or opioids due to additive sedation.
• Driving and machinery: caution patients who experience drowsiness before operating vehicles or heavy equipment.
• Pregnancy and lactation: use only if potential benefit justifies potential risk, as safety data are limited.
• Elderly patients: start at the lowest effective dose and monitor for increased sensitivity.
• Store at ambient temperature: keep below 25 °C, retain in original packaging and protect from moisture.

Levocetirizin can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Ketoconazole or other strong CYP3A4 inhibitors: may increase levocetirizin plasma levels and risk of sedation.
• Other H1‑antihistamines: concurrent use can enhance anticholinergic effects and excessive sedation.
• Monoamine oxidase inhibitors (MAOIs): may potentiate central nervous system depression.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers such as rifampicin: may reduce levocetirizin exposure and effectiveness.
• CNS depressants (e.g., alcohol, sedative hypnotics): may increase drowsiness.
• Theophylline: may experience altered theophylline metabolism.