Histisynt

Histisynt is an oral antihistamine medication whose active ingredient is levocetirizine dihydrochloride. It is supplied in tablet form (strength not specified) and is marketed in the European Union. Levocetirizine belongs to the selective peripheral H1‑receptor antagonist class and is used to alleviate symptoms of allergic conditions. The product is regulated as a prescription or over‑the‑counter drug depending on local regulations and may be dispensed by pharmacies.

Histisynt is indicated for the symptomatic relief of allergic conditions that involve histamine release.

- Allergic rhinitis (seasonal or perennial) - Chronic idiopathic urticaria (hives) - Other histamine‑mediated skin reactions such as pruritus - Relief of nasal congestion, sneezing, itching and watery eyes associated with allergies

Like other antihistamines, levocetirine may cause adverse reactions, most of which are mild and transient.

Common: - Drowsiness or mild sedation - Headache - Dry mouth - Fatigue

Serious: - Severe skin reactions such as Stevens‑Johnson syndrome - Anaphylactic‑type hypersensitivity

Before starting Histisynt, certain precautions should be considered to ensure safe use.

- Assess renal function; dose may need adjustment in severe impairment - Use caution in patients with a history of hypersensitivity to levocetirizine or related piperazine antihistamines - Avoid driving or operating machinery if drowsiness occurs - Consider pregnancy and breastfeeding status; consult a healthcare professional - Review concomitant medications that may increase sedation - Monitor for early signs of skin reactions during initial treatment

Levocetirizine can interact with other substances, influencing its efficacy or safety profile.

Avoid: - Strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) that may raise plasma levels

Use with caution: - Alcohol or other central nervous system depressants that may enhance sedation - Additional antihistamines or sedating drugs, increasing drowsiness risk - Theophylline, because both are metabolized by similar pathways - Antacids containing aluminum or magnesium if taken simultaneously, as they may affect absorption