Nasometin (Bilastine)

Nasometin (bilastine) is indicated for conditions mediated by histamine release, primarily within the allergic disease spectrum, offering non‑sedating relief.

• Allergic rhinitis: reduces nasal congestion, sneezing, itching and rhinorrhea associated with seasonal or perennial allergens.
• Chronic idiopathic urticaria: diminishes the number and size of wheals and alleviates associated itching.
• Seasonal allergic rhinitis: provides rapid relief of nasal and ocular symptoms triggered by pollen exposure.

• Bilastine acts as a selective peripheral H1‑receptor antagonist. By binding to the histamine H1 receptor on mast cells, basophils and vascular endothelium, it prevents histamine from triggering the intracellular cascade that leads to vasodilation, increased vascular permeability, and sensory nerve activation. This blockade reduces itching, swelling, and other allergic manifestations without crossing the blood‑brain barrier significantly, limiting central sedation.

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

Common Side Effects

• Headache: mild to moderate intensity, often transient.
• Dizziness: occasional sensation of light‑headedness.
• Dry mouth: reduced salivation, usually resolves with continued use.
• Nausea: mild gastrointestinal discomfort.
• Fatigue: low‑grade tiredness without impairment of daily activities.
• Nasal irritation: mild local irritation after oral administration.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Angioedema: swelling of face, lips, tongue or throat.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Cardiac arrhythmia: rare reports of palpitations or irregular heartbeat.
• Hepatic injury: very uncommon elevation of liver enzymes.

Before initiating therapy, consider the following safety measures.

• Renal impairment: assess kidney function and adjust use if necessary.
• Hepatic impairment: use with caution in patients with liver disease.
• Strong P‑gp inhibitors: avoid concomitant use with agents such as ketoconazole, erythromycin or itraconazole.
• Pregnancy: safety not established; discuss risks with a healthcare professional.
• Driving or operating machinery: monitor for any drowsiness or visual disturbances.
• Store at ambient temperature: keep in the original pack, protect from moisture and light.

Bilastine may interact with other medicines; awareness of the level of interaction helps guide safe use.

Major Interactions (Avoid)

• Strong P‑glycoprotein inhibitors (e.g., ketoconazole, erythromycin, itraconazole): may increase bilastine plasma concentrations.
• Fruit juices (apple, grapefruit, orange): can reduce oral absorption of bilastine.
• Cyclosporine: may elevate bilastine levels and increase risk of adverse effects.

Moderate Interactions (Monitor Closely)

• Alcohol: may enhance sedation in susceptible individuals.
• Other antihistamines: concurrent use can increase anticholinergic burden.
• CNS depressants (e.g., benzodiazepines): monitor for additive drowsiness.