Lergonix (Bilastine)

• Lergonix, a second‑generation H1‑antagonist, is used to manage allergic conditions by blocking peripheral histamine receptors.
• Allergic rhinitis: reduces nasal congestion, itching and sneezing associated with seasonal or perennial allergies.
• Chronic idiopathic urticaria: alleviates wheals and itching in patients with persistent hives of unknown cause.
• Seasonal allergic conjunctivitis: helps control eye itching and redness caused by pollen exposure.

• Bilastine selectively binds to peripheral H1‑histamine receptors, preventing histamine from triggering the cascade that leads to vasodilation, increased vascular permeability, and sensory nerve activation. By blocking this receptor, it reduces the typical signs of an allergic response without crossing the blood‑brain barrier in significant amounts, limiting central nervous system effects.

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

Common Side Effects

• Headache: mild to moderate pain often reported during early treatment.
• Dry mouth: sensation of oral dryness without actual salivary loss.
• Drowsiness: occasional mild sedation, less frequent than first‑generation antihistamines.
• Fatigue: feeling of reduced energy or tiredness.
• Nausea: mild stomach upset or queasiness.
• Dizziness: transient light‑headedness.

Serious or Rare Side Effects

• Anaphylaxis: severe, potentially life‑threatening allergic reaction.
• Stevens‑Johnson syndrome: rare skin blistering and mucosal involvement.
• Hepatotoxicity: abnormal liver function tests or jaundice.
• Cardiac arrhythmia: irregular heart rhythm in susceptible individuals.
• Severe hypotension: marked drop in blood pressure.
• Hematologic abnormalities: rare blood cell count changes.

Before initiating therapy with Lergonix, consider the following safety measures.

• Pregnancy: consult a healthcare professional; safety data are limited.
• Breastfeeding: discuss potential risks with a physician before use.
• Renal impairment: dose adjustment may be required in severe kidney dysfunction.
• Elderly patients: monitor for increased CNS effects such as drowsiness.
• Concomitant medications: review all current drugs for possible interactions.
• Store at room temperature: keep in the original packaging, protect from moisture and direct sunlight.

Bilastine may interact with several medicines; awareness helps avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Ketoconazole: strong CYP3A4 inhibition can raise bilastine plasma levels.
• Erythromycin: macrolide antibiotics may increase bilastine exposure.
• Diltiazem: calcium‑channel blocker may elevate bilastine concentrations.

Moderate Interactions (Monitor Closely)

• Alcohol: additive sedative effect may enhance drowsiness.
• Other antihistamines: combined use can increase risk of anticholinergic side effects.
• CNS depressants: may potentiate central nervous system depression.
• Grapefruit juice: can modestly affect bilastine metabolism.
• Rifampicin: enzyme induction may reduce bilastine effectiveness.