Hello Your son advised to take Augmentin -DS dry syrup for cold and cough . When you gave this medicine ,your son developed severe cold . No , this is not a side effect of augmentin ds ( amoxicillin+clavulanic acid )but in my opinion your son is suffering from allergic bronchitis and this ( allergy ) causes bronchoconstriction , this produces cough and cold . It was mere coincidence that you gave medicine and cold aggravated . But don t take tension . When such patient visit my clinic I advise my patient to take montelukast+ bambutrol ( 10 mg / kg body weight , each salt ) , once in a day . Hot coffee also act as bronchodilator. Continue augmentin ds as advised by your doctor , your son will get relief within a short period . But this is a prescription drug ,so please consult your doctor. Steam inhalation also provide instant relief . Hope this will help you. Good luck.