What can i take otc for a cough due to bronchitis what they prescribed guafesin cough syrup isn't helping at all my cough gets so bad at night & morng?

Dextromethorphan: Look for something with dextromethorphan in it... that will work better than guiafenesin. My personal favorite is Mucinex (guaifenesin) DM. (Actually any product with a DM behind it should have dextromethorphan). Cough is usually worse at night because of the body's biorhythms. It is worth looking into 'why' you have such a bad cough -if this doesn't work. (Sometimes if you have reactive airways it's worsened)