I'm sorry to hear you're experiencing irritation in your nose and throat along with nasal blockage. These symptoms are commonly associated with allergic reactions or upper respiratory tract irritation.

A medication like Histafree-M, which combines Montelukast (a leukotriene receptor antagonist) and Fexofenadine (an antihistamine), is often used to relieve such allergic symptoms. Montelukast helps reduce inflammation and mucus production in the airways, while Fexofenadine blocks histamine, which causes allergy symptoms like sneezing, runny or blocked nose, and throat irritation.

However, it's important to consult an allergy specialist or an ear, nose, and throat (ENT) doctor to confirm the cause of your symptoms and get appropriate treatment. They can evaluate whether your symptoms are due to allergies, infection, or another condition and recommend the best management plan.

If your symptoms worsen, you develop difficulty breathing, high fever, or severe discomfort, please seek immediate medical attention.

For now, try to avoid known allergens or irritants, stay hydrated, and rest. Please consult a specialist doctor for a thorough evaluation and personalized treatment.To narrow down potential causes, we will need some more information.Please tell me your age and gender.