Hello As you mentioned that you are taking UNICARBAZAN ( diethylcarbazine + chlorpheniramine maleate) as this is most potent drug for tropical eosinophilia and in allergy including asthmatic allergic bronchitis ( as may be in your case ). You are also taking montelukast + levoceterizine ( bot are most potent antihistamine ) . This is right that you got relief with these drugs but not cure. When such type of patient visit ( as all these symptoms may be due to bronchospasm caused by some allergens in your case )I usually prescribe only MONTELUKAST+BAMBUTEROLE once or twice in day . Usually patient respond at once and get complete relief in cough . Whenever cough recurs take again this tablet , and stop when complete cure . Hot coffee and steam inhalation also proved relief . Hope this will help you.