My 7 Month Old Son Had Cold Nd Cough From

My 7 month old son had cold nd cough from last 1 week. Now his cough totally cured but still stuffy nose. He had three Amikacin injections and on medication UVA CEF 50, COUGHMATE AND LEVOLIN. kindly suggest this medicines are correct then why he is having running nose. In how many it will cure