Hi Aarthi, Thank you for your query on Healthcare Magic. Frequent upper respiratory tract infections are common in preschool children with repeated cold and cough. Symptomatic treatment with oral antihistamines, mucolytics, and expectorants is enough to treat them. Maxtra contains oral antihistamine and is used in cold. And it is not helpful in cough due to nonallergic causes. And I advise you not to give medication without a prescription. As your child is having cough since 4 weeks, child needs physical examination by a Pediatrician to look into throat, ears, and lungs to know the cause of the prolonged cough. There is no permanent relief for cough and cold, but the frequency can be decreased by avoiding exposure to crowds, and patients with cold and cough. Nothing to worry as weight is within normal range for his age. Try to give infant solid food for weight gain and you can add some ghee or edible oil to make it more calorie dense. Hope I have answered your query.