Niesena (Bilastine)

• Bilastine is employed to manage allergic conditions that are driven by histamine release, providing symptom control in diseases of the respiratory tract and skin.
• Allergic rhinitis: alleviates nasal congestion, sneezing, itching and rhinorrhea, improving daily functioning and quality of life for patients with seasonal or perennial nasal allergy.
• Chronic idiopathic urticaria: reduces the frequency and intensity of wheals and flares, decreasing itching and discomfort in patients with persistent spontaneous hives.
• Allergic conjunctivitis: mitigates ocular itching, redness and tearing associated with histamine‑mediated eye allergy.

• Bilastine acts as a selective peripheral H1‑receptor antagonist. By binding to H1 receptors on mast cells, basophils and vascular endothelium, it prevents histamine from triggering the cascade that leads to vasodilation, increased vascular permeability, itching and swelling. This peripheral selectivity provides effective allergy relief while minimizing sedation.

Bilastine is generally well tolerated, but some patients may experience adverse reactions.

Common Side Effects

• Headache: mild to moderate headache reported during treatment.
• Drowsiness: occasional mild sedation, especially at higher doses.
• Dry mouth: reduced salivation leading to a dry oral cavity.
• Nausea: transient gastrointestinal discomfort.

Serious or Rare Side Effects

• Anaphylaxis: rare severe allergic reaction requiring immediate medical attention.
• Stevens‑Johnson syndrome: extremely rare skin disorder with blistering and mucosal involvement.
• Angioedema: swelling of deeper skin layers that may affect the airway.

When prescribing bilastine, clinicians should consider several precautionary measures to ensure safe use.

• Pregnancy: use only if the potential benefit outweighs the risk; limited data are available.
• Renal impairment: assess kidney function; dose adjustment may be required in severe cases.
• Elderly: monitor for increased sedation or dizziness due to age‑related pharmacodynamics.
• Concomitant CNS depressants: avoid or use with caution as additive sedative effects may occur.
• Drug interactions: review patient medication list for agents that may alter bilastine exposure.
• Store at ambient temperature: keep below 25 °C in the original packaging, protect from moisture and direct sunlight.

Bilastine may interact with other medicines; understanding the interaction potential helps prevent reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Ketoconazole: strong CYP3A4 inhibitor that can markedly increase bilastine plasma levels.
• Erythromycin: macrolide antibiotic that may raise bilastine concentrations.
• Ritonavir: protease inhibitor that significantly elevates bilastine exposure.

Moderate Interactions (Monitor Closely)

• Antacids containing aluminum or magnesium: can reduce bilastine absorption; separate administration by at least 2 hours.
• Alcohol: may enhance sedative effects of bilastine.
• Other sedating antihistamines: concurrent use can increase drowsiness.