Nefoxef (Fexofenadine Hydrochloride)

• Nefoxef (fexofenadine) acts on peripheral H1 receptors to relieve allergy‑related symptoms across several common allergic conditions.
• Allergic rhinitis: reduces nasal congestion, sneezing, itching and watery discharge.
• Seasonal allergic rhinitis (hay fever): alleviates hay‑fever symptoms during pollen season.
• Chronic idiopathic urticaria: diminishes the number and severity of hives and associated itching.
• Perennial allergic rhinitis: provides year‑round symptom control for continuous allergen exposure.
• Allergy‑induced conjunctivitis: helps reduce eye itching and redness associated with allergic eye disease.

• Fexofenadine hydrochloride is a selective peripheral H1‑receptor antagonist. By binding to the histamine H1 receptors on mast cells, basophils and other target tissues, it prevents histamine from triggering the cascade that leads to vasodilation, increased vascular permeability and sensory nerve stimulation. The drug does not cross the blood‑brain barrier appreciably, resulting in minimal central nervous system effects.

Fexofenadine may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Headache: mild to moderate headache, usually transient.
• Dry mouth: sensation of oral dryness, may improve with fluid intake.
• Drowsiness: occasional mild sedation, generally not impairing daily activities.
• Nausea: transient stomach upset, often resolves without intervention.

Serious or Rare Side Effects

• Cardiac arrhythmia: irregular heart rhythm that may require medical evaluation.
• Severe allergic reaction: anaphylaxis or angioedema presenting with swelling and breathing difficulty.
• Hepatotoxicity: signs of liver injury such as jaundice, dark urine or elevated enzymes.
• Blood dyscrasias: rare abnormalities in blood cell counts, including neutropenia or thrombocytopenia.

When prescribing or dispensing Nefoxef, several precautionary measures should be considered to ensure safe use.

• Renal impairment: dose adjustment may be required in patients with reduced kidney function.
• Hepatic impairment: monitor liver function in patients with existing liver disease.
• Concomitant CNS depressants: avoid combining with alcohol or sedatives that may increase drowsiness.
• Pregnancy: use only if clearly needed after risk‑benefit assessment.
• Elderly: start at lower dose and monitor for adverse effects.
• Store at ambient temperature: keep below 25 °C, protect from moisture and light in original packaging.

Fexofenadine can interact with several medicines, altering its absorption or effect.

Major Interactions (Avoid)

• Antacids containing aluminum or magnesium: reduce fexofenadine absorption.
• Erythromycin or azithromycin: increase systemic exposure, risk of side effects.
• Ketoconazole or other potent CYP3A4 inhibitors: may raise plasma levels.

Moderate Interactions (Monitor Closely)

• Alcohol: may enhance drowsiness.
• Other antihistamines: additive sedation.
• Warfarin: monitor INR as fexofenadine may affect anticoagulation.