Hi XXXXXXX,
Welcome to XXXXXXX forum.

Are you getting difficulty in breathing/ chest pain/ high grade fever?
At what time cough is worsening? Whether whole day or at night times.

With the available described symptoms, there Appears to be possibility of influenza fever which is also called as common cold.
Presence of cough with cold suggests the diagnosis.
At times these viral infection are also associated with asthmatic bronchitis and as your condition is not improving after taking XXXXXXX syrup, this possibility should also be kept in mind.
Other possibility could be impending pneumonia , irritation of cough centre, cough variant asthma (all investigation and clinical examinations are normal, yet patient has cough).

You should consult with XXXXXXX medicine specialist and should go for thorough check up.
Possibility of asthmatic bronchitis and other pathology could be differentiated only by clinical examinations.
You should go for chest x XXXXXXX complete hemogram, erythrocyte sedimentation rate (ESR).
Meanwhile, you should take codeine sulphate syrup, benzanotate on written prescription.
Use of bronchodilators is decided after clinical examinations.
You should perform gargle three times in day; a glass of lukewarm water with a pinch of salt.
Avoid cold drinks and oily food.

Hope that helps.
Let me know your other queries.
Take care,
Dr. Mayank Bhargava

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