Histaclar (Loratadine)

Histaclar is indicated for the temporary relief of symptoms associated with various allergic conditions.

• Allergic rhinitis (seasonal and perennial) causing sneezing, nasal congestion, and runny nose
• Itching, redness, and watery eyes due to allergic conjunctivitis
• Chronic idiopathic urticaria (hives) with associated skin itching and rash
• Relief of itching and rash caused by allergic skin reactions
• Management of mild to moderate allergic conjunctivitis symptoms

• Histaclar’s active ingredient, loratadine, selectively binds to peripheral H1 histamine receptors, preventing histamine from activating these sites. By antagonizing the H1 receptor, loratadine inhibits the cascade that leads to vasodilation, increased vascular permeability, and sensory nerve stimulation, which are responsible for typical allergic manifestations such as itching, swelling, and rhinorrhea. Its limited ability to cross the blood‑brain barrier reduces central nervous system effects, distinguishing it from first‑generation antihistamines.

Like all medicines, Histaclar may cause unwanted effects, although many people experience none.

Common

• Headache
• Dry mouth
• Fatigue
• Nausea
• Mild drowsiness (rare)

Serious

• Severe skin rash or hives
• Swelling of the face, lips, or tongue (angioedema)
• Rapid heartbeat or palpitations
• Difficulty breathing or wheezing
• Elevated liver enzymes (rare)

Before using Histaclar, consider the following precautions to ensure safe and appropriate use.

• Not recommended for children under 2 years without medical advice
• Use caution if you have liver or kidney impairment
• Avoid if you have known hypersensitivity to loratadine or any excipients
• Discuss with a healthcare professional before use during pregnancy or breastfeeding
• Inform your doctor of any existing heart rhythm disorders
• Consider possible interaction with alcohol or other sedating substances
• Keep the product out of reach of children

Histaclar can interact with other medicines; some combinations should be avoided while others require monitoring.

Avoid

• Strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin)
• Monoamine oxidase inhibitors (MAOIs) taken within 14 days
• Other antihistamines or sedating antihistamines
• Excessive alcohol consumption

Use with caution

• Antifungal agents that moderately inhibit CYP3A4 (e.g., fluconazole)
• Certain antidepressants (e.g., sertraline)
• Theophylline
• Medications that may prolong the QT interval