Tebast

• Allergic Rhinitis: Treatment of symptoms associated with seasonal and perennial allergic rhinitis, including sneezing, nasal congestion, rhinorrhea, and nasal itching.
• Chronic Idiopathic Urticaria: Relief of itching and wheals associated with chronic idiopathic urticaria.
• Other Allergic Conditions (Off-label): Used in certain cases for allergic conjunctivitis and other histamine-mediated allergic disorders.

• Adults and Adolescents (12 years and older):
• Usual dose: 10 mg orally once daily.
• May be increased to 20 mg once daily depending on clinical response.
• Children (6 to 11 years):
• Recommended dose: 5 mg orally once daily.
• Elderly:
• Same dosing as adults; monitor for tolerability due to possible comorbidities.
• Renal Impairment:
• No dosage adjustment generally required for mild to moderate impairment. Use with caution in severe impairment.
• Hepatic Impairment:
• Dose adjustment recommended in moderate hepatic impairment; contraindicated in severe hepatic impairment.
• Route of Administration: Oral tablets or oral suspension, with or without food.
• Duration of Therapy: Depends on condition severity and response; often seasonal for allergic rhinitis or continuous for chronic urticaria.

Ebastine is a selective, long-acting second-generation H1 histamine receptor antagonist. It competitively blocks peripheral H1 receptors, preventing histamine from binding and exerting its effects. This inhibition reduces the typical symptoms of allergic reactions such as vasodilation, increased vascular permeability, and sensory nerve stimulation, resulting in decreased sneezing, itching, and urticaria. Ebastine’s low penetration into the central nervous system minimizes sedative effects compared to first-generation antihistamines.

• Absorption: Rapid and efficient oral absorption; peak plasma concentration of its active metabolite, carebastine, occurs approximately 2–3 hours after administration.
• Bioavailability: Approximately 40%, increased when taken with food.
• Distribution: Widely distributed; about 97% plasma protein binding.
• Metabolism: Extensively metabolized in the liver primarily via CYP3A4 to active metabolite carebastine.
• Half-life:
• Ebastine: ~1.5 hours
• Carebastine (active metabolite): 15 to 19 hours, allowing once-daily dosing.
• Excretion: Mainly excreted through urine (around 60%) and feces (approximately 20%), largely as metabolites.

• Pregnancy:
• Limited data in humans. Animal studies show no direct teratogenic effects. Use only if clearly needed and after careful risk-benefit assessment.
• Lactation:
• Ebastine is excreted in small amounts in human breast milk. Caution advised; monitor nursing infants for adverse effects.
• General: Data are insufficient for definitive safety conclusions; caution is recommended.

• Primary Therapeutic Class: Antihistamine
• Subclass: Second-generation H1 receptor antagonist (non-sedating)

• Hypersensitivity to ebastine or any component of the formulation.
• Severe hepatic impairment.
• Concurrent use with strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin).
• Known congenital or acquired QT prolongation or cardiac arrhythmias.

• Use with caution in patients with predisposing factors for QT prolongation (e.g., electrolyte imbalance, cardiac disease).
• Avoid concomitant use with other drugs that prolong QT interval.
• Monitor liver function in patients with hepatic impairment.
• Although sedation is rare, avoid alcohol or CNS depressants concomitantly to prevent additive effects.
• Careful monitoring in elderly patients is recommended.

• Common:
• Headache
• Dry mouth
• Fatigue or mild sedation (rare)
• Gastrointestinal disturbances such as nausea or abdominal discomfort
• Less common:
• Dizziness
• Palpitations
• Rare but serious:
• QT prolongation and associated arrhythmias
• Hypersensitivity reactions including rash and angioedema
• Onset of side effects typically occurs early during treatment. Most adverse events are mild and dose-independent at therapeutic levels.

• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin, ritonavir): Can significantly increase plasma concentrations of ebastine and risk QT prolongation.
• CYP3A4 inducers (e.g., rifampicin, carbamazepine): May reduce plasma concentrations, lowering efficacy.
• Other QT-prolonging agents: Increase risk of cardiac arrhythmias.
• Alcohol: May enhance CNS depressant effects but minimal due to low sedation potential.
• Antacids: May reduce absorption; separate administration by at least two hours.

• No major recent changes in approved indications or dosing regimens.
• Regulatory agencies continue to recommend avoiding co-administration with strong CYP3A4 inhibitors to prevent cardiac risk.
• Ongoing pharmacovigilance affirms ebastine’s safety and efficacy as a preferred second-generation antihistamine with low sedative potential.

• Store at controlled room temperature, 20°C to 25°C (68°F to 77°F).
• Protect from moisture, heat, and light.
• Keep container tightly closed.
• Do not freeze.
• Shake oral suspension well before use; use within the manufacturer’s recommended period after opening (commonly 14 days).