Kestine (Ebastine)

• Ebastine acts on histamine‑mediated allergic pathways and is indicated for the following conditions:
• Allergic rhinitis: reduces nasal congestion, sneezing, itching and watery discharge.
• Seasonal allergic rhinitis: provides symptom relief during pollen or seasonal allergen exposure.
• Chronic idiopathic urticaria: decreases the frequency and severity of hives and associated itching.

• Ebastine selectively blocks peripheral H1 histamine receptors, preventing histamine from binding to mast cells and basophils. This inhibition reduces the vascular permeability, smooth‑muscle contraction, and sensory nerve activation that underlie the classic signs of allergic reactions, thereby alleviating symptoms without significant central nervous system penetration.

Ebastine may cause adverse reactions; reported events are grouped by frequency.

Common Side Effects

• Headache: mild to moderate intensity.
• Drowsiness or fatigue: transient, often improves with continued use.
• Dry mouth: occasional, resolves after hydration.
• Nausea or abdominal discomfort: mild gastrointestinal upset.
• Dizziness: brief episodes, usually non‑serious.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips or throat requiring immediate medical attention.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Cardiac arrhythmias: rare reports of QT prolongation.
• Anaphylaxis: life‑threatening hypersensitivity reaction.
• Hepatic dysfunction: abnormal liver enzymes in isolated cases.

• When prescribing ebastine, consider the following precautions to ensure safe use.
• Pregnancy: consult a healthcare professional before use; safety data are limited.
• Elderly patients: monitor for increased sedation or dizziness.
• Renal impairment: dose adjustment may be required in severe dysfunction.
• Concomitant antihistamines: avoid additive antihistaminic effects.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Ebastine can interact with other medicines; interactions are classified by clinical significance.

Major Interactions (Avoid)

• Ketoconazole: may increase ebastine plasma concentrations.
• Erythromycin: can raise ebastine levels, increasing risk of side effects.
• Ritonavir: potent CYP3A4 inhibitor that elevates ebastine exposure.

Moderate Interactions (Monitor Closely):\n- Theophylline: may enhance central nervous system effects.

• CNS depressants (e.g., benzodiazepines): additive sedation possible.
• Alcohol: may increase drowsiness and impair coordination.