Benzonatate
"Absolutely worthless.  I went to a clinic on Thanksgiving day and was diagnosed with an upper respiratory infection.  The doctor prescribed this and my cough has gotten SIGNIFICANTLY worse.  I'm  completely irritated.  I can't sleep, and I'm about to go to the drug store and just buy some damned cough syrup.  I'm not surprised at all to see all the one-star reviews.  Wish I could give it ZERO."