A cough with phlegm lasting for two weeks despite treatment may mean that the cause is not only an allergy or a simple cold. Conditions such as bronchitis, sinus infection with post-nasal drip, asthma, acid reflux, or a bacterial chest infection may need to be considered. The medicines you mentioned mainly help with allergy symptoms, mucus thinning, and cold-related discomfort, but they may not fully address the underlying cause. Instead of changing medicines repeatedly on your own, it is important to see a doctor, especially since the cough has persisted for this long. The doctor may need to listen to your chest and sometimes advise tests, such as a chest X-ray or sputum examination. Meanwhile, drinking warm fluids, steam inhalation, and avoiding smoke, dust, and cold air may help reduce symptoms. A different expectorant or mucolytic medicine, such as ambroxol or acetylcysteine, may sometimes be used, depending on the type of phlegm and associated symptoms. Antibiotics should only be taken if a bacterial infection is confirmed or strongly suspected. Seek urgent care if you develop breathlessness, chest pain, fever, or blood in sputum.

Your symptoms may be due to a viral cold along with allergy-related throat irritation. Allergies can cause post-nasal drip, in which mucus runs down the throat, leading to a sore throat, irritation, coughing, and frequent throat clearing. Dust, smoke, weather changes, or pollen may worsen these symptoms. Antihistamine medicines such as cetirizine, levocetirizine, loratadine, or fexofenadine are often used to reduce allergy symptoms such as sneezing, a runny nose, and throat irritation. Warm saltwater gargles can help soothe throat pain, while steam inhalation can reduce nasal congestion and improve breathing. Drinking warm fluids, such as herbal teas and soup, can also provide relief. If you have a fever or body pain, paracetamol may help when taken in the recommended dose. Try to avoid cold drinks, smoking, and dusty environments, as these can worsen irritation and coughing. Most mild viral colds improve within a few days with rest and fluids. However, if you develop a high fever, pus on the tonsils, difficulty breathing, severe throat pain, or if your symptoms last more than 1 to 2 weeks, you should consult a doctor for a proper examination and treatment.